Theuns, D.A.M.J.

Ventricular fibrillation and life-threatening ventricular tachycardia in the setting of outflow tract arrhythmias - The place of ICD therapy (Article)

2013-05-10T00:00:00Z

The Entirely Subcutaneous Implantable Cardioverter-Defibrillator. Initial Clinical Experience in a Large Dutch Cohort (Article)

2012-10-11T00:00:00Z

Objectives: The purpose of the study was to evaluate the efficacy and safety of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD). Background: A new entirely S-ICD has been introduced, that does not require lead placement in or on the heart. The authors report the largest multicenter experience to date with the S-ICD with a minimum of 1-year follow-up in the first 118 Dutch patients who were implanted with this device. Methods: Patients were selected if they had a class I or IIa indication for primary or secondary prevention of sudden cardiac death. All consecutive patients from 4 high-volume centers in the Netherlands with an S-ICD implanted between December 2008 and April 2011 were included. Results: A total of 118 patients (75% males, mean age 50 years) received the S-ICD. After 18 months of follow-up, 8 patients experienced 45 successful appropriate shocks (98% first shock conversion efficacy). No sudden deaths occurred. Fifteen patients (13%) received inappropriate shocks, mainly due to T-wave oversensing, which was mostly solved by a software upgrade and changing the sensing vector of the S-ICD. Sixteen patients (14%) experienced complications. Adverse events were more frequent in the first 15 implantations per center compared with subsequent implantations (inappropriate shocks 19% vs. 6.7%, p = 0.03; complications 17% vs. 10%, p = 0.10). Conclusions: This study demonstrates that the S-ICD is effective in terminating ventricular arrhythmias. There is, however, a considerable percentage of ICD related adverse events, which decreases as the therapy evolves and experience increases.

Beta-blocker therapy is not associated with symptoms of depression and anxiety in patients receiving an implantable cardioverter-defibrillator (Article)

2012-01-01T00:00:00Z

Beta-blockers are frequently prescribed to implantable cardioverter-defibrillator (ICD) patients. Beta-blocker therapy has been proposed to induce emotional distress such as depression and anxiety, but a paucity of studies has examined the relationship between beta-blockers and distress. We investigated the association between beta-blocker therapy, including type and dosage, and symptoms of anxiety and depression in a consecutive cohort of patients receiving an ICD. Between 2003 and 2010, 448 consecutively implanted ICD patients were enrolled in the prospective Mood and personality as precipitants of arrhythmia in patients with an Implantable cardioverter Defibrillator: A prospective Study (MIDAS), of which 429 completed the Hospital Anxiety and Depression Scale (HADS) and the ICD Patient Concerns questionnaire (ICDC) at baseline. Eighty per cent of all patients received beta-blocker therapy. In univariate analysis, beta-blocker therapy was not significantly associated with symptoms of anxiety, depression, and ICD concerns (β = -0.030, β = 0.007, and β = -0.045, respectively; all P's >0.36). Type of beta-blocker showed a trend towards significance for mean levels of ICD concerns (P = 0.09). No association was found between dosage and emotional distress (all P's >0.21). After adjustment for relevant clinical and demographic variables, the association of beta-blocker therapy and symptoms of anxiety, depression, and ICD concerns remained non-significant (β = 0.009, β = 0.037, and β = 0.019, respectively; all P's >0.47). In patients receiving an ICD, beta-blocker therapy was not associated with symptoms of anxiety, depression, and ICD concerns. Research is warranted that further elucidates the link between beta-blocker therapy and emotional distress in this vulnerable patient group.

Health care utilisation after defibrillator implantation for primary prevention according to the guidelines in 2 Dutch academic medical centres (Article)

2011-12-14T00:00:00Z

Background The benefit of implantable defibrillators (ICDs) for primary prevention remains debated. We analysed the implications of prophylactic ICD implantation according to the guidelines in 2 tertiary hospitals, and made a healthcare utilisation inventory. Methods The cohort consisted of all consecutive patients with coronary artery disease (CAD) or dilated cardiomyopathy (DCM) receiving a primary prophylactic ICD in a contemporary setting (2004-2008). Follow-up was obtained from hospital databases, and mortality checked at the civil registry. Additional data came from questionnaires sent to general practitioners. Results There were no demographic differences between the 2 centres; one had proportionally more CAD patients and more resynchronisation therapy (CRT-D). The 587 patients were followed over a median of 28 months, and 50 (8.5%) patients died. Appropriate ICD intervention occurred in 123 patients (21%). There was a small difference in interventionfree survival between the 2 centres. The questionnaires revealed 338 hospital admissions in 52% of the responders. Device-related admissions happened on 68 occasions, in 49/ 276 responders. The most frequently reported ICD-related admission was due to shocks (20/49 patients); for other cardiac problems it was mainly heart failure (52/99). Additional outpatient visits occurred in 19%. Conclusion Over a median follow-up of 2 years, one fifth of prophylactic ICD patients receive appropriate interventions. A substantial group undergoes readmission and additional visits. The high number of admissions points to a very ill population. Overall mortality was 8.5%. The 2 centres employed a similar procedure with respect to patient selection. One centre used more CRT-D, and observed more appropriate ICD interventions.

Long-term follow-up of prophylactic implantable cardioverter-defibrillator- only therapy: Comparison of ischemic and nonischemic heart disease (Article)

2011-12-01T00:00:00Z

Background: The benefits of primary prophylactic implantable cardioverter-defibrillators (ICDs) are actually debated, as some drawbacks become more apparent and as the natural history of cardiac disease seems to improve. Therefore, contemporary follow-up data of non-trial populations treated according to current guidelines remain necessary. The aim of this study was to evaluate mortality and the occurrence of ICD interventions in patients with coronary artery disease (CAD) and dilated cardiomyopathy (DCM) who received in the recent era a primary prophylactic ICD without resynchronization therapy. Hypothesis: Survival and event-free rates from appropriate ICD therapy are different between ischemic and nonischemic ICD patients. Methods: Prospective cohort study of 427 consecutive primary prevention ICD patients with ischemic or nonischemic heart disease, excluding patients with resynchronization. Results: Ischemic heart disease was present in 290 patients (68%), nonischemic heart disease in 137 patients (32%). During a median follow-up of 31 months (interquartile range [IQR] 15-45 months), 30 patients (7%) died. Mortality was not different in both disease categories. The incidence of appropriate ICD interventions was similar in CAD and DCM (23% vs 21%). Appropriate ICD intervention occurred more frequently in patients with atrial fibrillation (29% vs 19%). Inappropriate ICD intervention occurred in 11% of patients. Conclusions: The clinical course of ischemic and nonischemic heart disease patients treated with a primary prophylactic ICD is similar with respect to mortality and to appropriate and inappropriate ICD interventions, in spite of a younger age at baseline of the DCM patients.

Gender disparities in anxiety and quality of life in patients with an implantable cardioverterdefibrillator (Article)

2011-12-01T00:00:00Z

AimsA paucity of studies in implantable cardioverterdefibrillator (ICD) patients has examined gender disparities in patient-reported outcomes, such as anxiety and quality of life (QoL). We investigated (i) gender disparities in anxiety and QoL and (ii) the magnitude of the effect of gender vs. New York Heart Association (NYHA) functional class (III/IV), ICD shock, and Type D personality on these outcomes. Methods and resultsImplantable cardioverterdefibrillator patients (n 718; 81 men) completed the State-Trait Anxiety Inventory (STAI) and the Short-Form Health Survey 36 (SF-36) at baseline and 12 months post-implantation. The magnitude of the effect was indicated using Cohens effect size index. Multivariate analysis of covariance for repeated measures showed no differences between men and women on mean scores of anxiety (F(1,696) 2.67, P 0.10). Differences in QoL were observed for only two of the eight subscales of the SF-36, with women reporting poorer physical functioning (F(1,696) 7.14, P 0.008) and vitality (F(1,696) 4.88, P 0.028) than men. With respect to anxiety, effect sizes at baseline and 12 months for gender, NYHA class, and ICD shocks were small. A large effect size for Type D personality was found at both time points. For QoL, at baseline and 12 months, the effect sizes for gender were small, while the influence of NYHA class and Type D personality was moderate to large. ConclusionsMen and women did not differ on mean anxiety or QoL scores, except for women reporting poorer QoL on two domains. The relative influence of gender on anxiety and QoL was less than that of NYHA functional class and Type D personality.

Pre implantation psychological functioning preserved in majority of implantable cardioverter defibrillator patients 12 months post implantation (Article)

2011-11-07T00:00:00Z

Background: The impact of ICD therapy on patient well being has typically focused on mean differences between groups, thereby neglecting changes within individuals. Using an intra-individual approach, we examined (i) the prevalence of implantable cardioverter defibrillator (ICD) patients maintaining their pre implantation level of psychological functioning at 12 months, and (ii) factors associated with deterioration in functioning. Methods: Consecutively implanted ICD patients (n = 332) completed a set of standardized and validated patient reported measures at baseline and at 12 months post implantation. Results: The majority of patients (72.8% to 81.7%) preserved their pre implantation level of psychological functioning 12 months post implantation. In adjusted analysis, ICD shock (all ps < .001) and Type D personality (all ps < .05) were independent predictors of deterioration in psychological functioning at 12 months across all domains, while baseline psychological status was associated with an improvement (all ps < .05). Patients with a primary prevention indication experienced a decrease in ICD concerns (p = .03) and anxiety (p = .006), and older patients (p = .04) a decrease in anxiety symptoms during the follow-up period. By contrast, patients with left ventricular dysfunction (p = .007) and atrial fibrillation (p = .02) were more likely to experience an increase in anxiety. Conclusions: The majority of ICD patients maintained their pre implantation level of psychological functioning at 12 months. A subset of patients was at risk of poor psychological adaptation, attributable to ICD shocks, Type D personality, atrial fibrillation, and left ventricular dysfunction, while primary prevention indication and older age had a protective effect against deterioration in functioning.

Impact of left ventricular ejection fraction on occurrence of ventricular events in defibrillator patients with coronary artery disease (Article)

2011-11-01T00:00:00Z

Aims Primary preventive implantable cardioverter defibrillator (ICD) therapy is indicated in patients with coronary artery disease (CAD) and left ventricular ejection fraction (LVEF) of ≤35, but some patients in the major trials had LVEF in the range of 3035. We hypothesized that these patients constitute a lower-risk population and might derive less benefit from ICD therapy. Methods and results In this retrospective study, patients with CAD in whom an ICD was implanted for primary prevention were studied. We determined the incidence of ICD therapies in two predefined LVEF cut-off groups (≤/>20%; ≤/>30%), predictors of ICD therapies, and overall mortality. A total of 536 patients were included: 88 male, age 63 ± 10 years, follow-up 30 ± 25 months. In all, 115 patients (22) experienced appropriate ICD interventions; in 36% of them, the arrhythmia was treated with shock. Inappropriate therapy was delivered in 8%. Cumulative mortality at 5 years was 20%. Using our two cut-off levels, more ICD-therapies occurred in patients with poorer LVEF, but the difference was significant only with the cut-off value of ≤/>20%. Only 2 of 12 parameters were predictors of appropriate ICD therapy: age, odds ratio (OR) 1.047 (1.015-1.079) per year and QRS width, OR 1.014 per ms (1.004-1.024). Conclusion Refined risk stratification using different LVEF cut-off levels is not helpful in patients with CAD and LVEF ≤35. Mortality was lower than in randomized trials in this real-world setting, probably due to better drug treatment at implant.

Effect of cardiac resynchronization therapy-defibrillator implantation on health status in patients with mild versus moderate symptoms of heart failure (Article)

2011-10-15T00:00:00Z

Indications for cardiac resynchronization therapy (CRT) have expanded to include patients with mild congestive heart failure (CHF) symptoms (New York Heart Association [NYHA] functional class II) because of a demonstrated morbidity reduction in this subset of patients. However, little is known about postimplantation changes in their self-reported health status compared to patients with more severe CHF. The aim of this study was to examine the influence of baseline NYHA functional class on health status changes in the first 12 months after implantation of a CRT with defibrillator (CRT-D). Patients with first-time CRT-D (n = 169, 75% men, mean age 62.1 ± 10.7 years) were recruited from 3 Dutch hospitals. All patients completed the SF-36 Health Survey at the time of implantation and at 12 months after implantation. Mildly (NYHA functional class II; n = 54) and moderately (NYHA functional class III; n = 115) symptomatic CHF patients showed improved health status in several SF-36 domains at 12 months after CRT-D. When adjusting for baseline health status, the groups did not differ with respect to their health status improvement over time, but after adjustment for demographic and clinical factors, the mildly symptomatic patients reported relatively more improvement in general health (B = 10.15, SE = 3.31, p = 0.003) and social functioning (B = 10.64, SE = 3.74, p = 0.005). In conclusion, NYHA functional class II patients reported equal, and in some domains even more, improvement in health status compared to NYHA functional class III patients at 12 months after CRT-D. Hence, CRT not only prevents clinical adverse events in patients with mild CHF symptoms but also improves health status.

Clinical experience with a novel subcutaneous implantable defibrillator system in a single center (Article)

2011-09-01T00:00:00Z

Background: Implantable cardioverter-defibrillators (ICDs) reduce mortality in both primary and secondary prevention, but are associated with substantial short- and long-term morbidity. A totally subcutaneous ICD (S-ICD) system has been developed. We report the initial clinical experience of the first 31 patients implanted at our hospital. Methods: All patients had an ICD indication according to the ACC/AHA/ESC guidelines. The first 11 patients were part of the reported CE trial. The implantation was performed without fluoroscopy. The device was implanted subcutaneously in the anterior axillary line, with a parasternal lead tunneled from the xiphoid to the manubrial-sternal junction. Ventricular fibrillation (VF) was induced to assess detection accuracy and defibrillation efficacy using 65 J shocks. Results: Post-implant, 52 sustained episodes of VF were induced. Sensitivity was 100% and induced conversion efficacy was 100% (with standard polarity in 29 patients). Mean time to therapy was 13.9 ± 2.5 s (range 11-21.6 s). Late procedure-related complications were observed in 2 of the first 11 implantations (lead migration). During follow-up, spontaneous ventricular arrhythmias occurred in four patients, with accurate detection of all episodes. Inappropriate therapy was observed in five patients. Recurrences were prevented with reprogramming. Conclusions: The S-ICD system can be implanted without the use of fluoroscopy by using anatomical landmarks only. Episodes of VF were accurately detected using subcutaneous signals, and all induced and clinical episodes were successfully converted. The S-ICD system is a viable alternative to conventional ICD systems for selected patients.

Indications and outcome of implantable cardioverter-defibrillators for primary and secondary prophylaxis in patients with noncompaction cardiomyopathy (Article)

2011-08-01T00:00:00Z

Prophylactic ICDs for Noncompaction Cardiomyopathy. Background: Noncompaction cardiomyopathy (NCCM) is a rare, primary cardiomyopathy, with initial presentation of heart failure, emboli, or arrhythmias, including sudden cardiac death. Implantable cardioverter-defibrillators (ICDs) are frequently used for primary and secondary prevention in different cardiomyopathy patients, but data about ICD in NCCM are scarce. The aim of this study was, therefore, to investigate ICD indications and outcomes in NCCM patients. Methods and Results: We collected prospective data from our NCCM cohort (n = 77 pts, mean age: 40 ± 14 years). ICD was implanted in 44 (57%) patients with NCCM according to the current ICD guidelines for nonischemic cardiomyopathies: in 12 for secondary prevention (7 × ventricular fibrillation, 5 × sustained ventricular tachycardia [VT]) and in 32 patients for primary prevention (heart failure/severe LV dysfunction). During a mean follow-up of 33 ± 24 months, 8 patients presented with appropriate ICD shocks due to sustained VT after median 6.1 [1-16] months. This included 4 of 32 (13%) patients in the primary prevention group and 4 of 12 (33%) in the secondary prevention group (P = 0.04). 9 patients presented with inappropriate ICD therapy: 6 (19%) in the primary and 3 (25%) in the secondary prevention group, at a median follow-up of 4 (2-23) months. Conclusions: In our cohort of NCCM patients, an ICD was frequently implanted for primary or secondary prevention of sudden cardiac death. At follow-up, frequent appropriate ICD therapy was observed in both groups, supporting the application of current ICD guidelines for primary and secondary prevention of sudden cardiac death in NCCM.

Relation of symptomatic heart failure and psychological status to persistent depression in patients with implantable cardioverter-defibrillator (Article)

2011-07-01T00:00:00Z

Studies on psychological morbidity in patients with an implantable cardioverter-defibrillator (ICD) have focused on mean differences rather than intraindividual differences. Such an approach masks the chronicity of symptoms in individual patients and the potential differences in cardiac outcomes. We examined the prevalence and correlates of persistent depression using an intraindividual approach. Consecutive patients who had undergone ICD implantation (n = 386; 79.3% men) completed a set of validated questionnaires, including the Hospital Anxiety and Depression Scale (HADS), at baseline and 3 months after implantation. Information on ICD therapies was obtained by device interrogation. At 3 months after implantation, 52 (14%) of the 386 patients had persistent depression (HADS cutoff <8 before and 3 months after implantation). Heart failure (odds ratio [OR] 2.29; 95% confidence interval [CI] 1.26 to 4.15), cardiac resynchronization therapy (OR 1.92; 95% CI 1.05 to 3.52), New York Heart Association class III-IV (OR 2.47; 95% CI 1.36 to 4.48), diabetes (OR 2.09; 95% CI 1.01 to 4.29), Type D personality (OR 8.30; 95% CI 4.42 to 15.58), high levels of ICD concerns (OR 2.60; 95% CI 1.44 to 1.71), diuretics (OR 2.41; 95% CI 1.26 to 4.61), and psychotropic medication (OR 3.58; 95% CI 1.86 to 6.90) were all significant univariate correlates of persistent depression at 3 months. No effect was found for ICD shock during follow-up (OR 1.59; 95% CI 0.57 to 4.41). In adjusted analysis, New York Heart Association class III-IV (OR 2.95; 95% CI 1.47 to 5.89), Type D personality (OR 7.98; 95% CI 3.98 to 16.04), and the use of psychotropic medication (OR 2.73; 95% CI 1.27 to 5.84) were independent correlates of persistent depression. In conclusion, symptomatic heart failure, psychological status, and psychotropic medication use predicted persistent depression after ICD implantation.

Risk of chronic anxiety in implantable defibrillator patients: A multi-center study (Article)

2011-03-17T00:00:00Z

Background: Little is known about the prevalence of chronic anxiety in patients with an implantable cardioverter defibrillator (ICD). In a multi-center, prospective study, we examined 1) the prevalence of chronic anxiety (i.e., patients anxious at implantation and 12 months), and 2) predictors of chronic anxiety. Methods: ICD patients (N = 284; 21.1% women) anxious (cut-off ≥ 40 on the State Trait Anxiety Inventory (STAI)) at the time of implantation qualified for inclusion in the current study. Patients completed the Type D Scale at baseline and the STAI (state measure) at baseline and 12 months. Results: Of 284 patients anxious at baseline, 53.9% (153/284) remained anxious at 12-month follow-up. Diabetes (OR:2.49; 95%CI:1.16-5.36), cardiac resynchronization therapy (CRT) (OR:2.03; 95%CI:1.02-4.05), and Type D personality (OR:1.87; 95%CI:1.09-3.19) were independent predictors of 12-month anxiety, adjusting for demographic and clinical variables including ICD therapy during follow-up. Shocks (both appropriate and inappropriate during follow-up) were not associated with chronic anxiety at 12 months (OR:0.94; 95%CI:0.42-2.12). The prevalence of chronic anxiety in the 96 patients with no risk factors was 34.4% and 63.8% in the 120 patients with either diabetes, CRT, or Type D personality. Conclusions: More than 50% of ICD patients anxious at the time of implantation were still anxious at 12 months, indicating a high level of chronicity. Diabetes, CRT, and Type D personality were independent predictors of chronic anxiety. ICD patients anxious at implantation should be closely monitored and offered adjunctive psychosocial intervention if symptoms do not remit spontaneously in order to prevent adverse health outcomes.

The prognosis of implantable defibrillator patients treated with cardiac resynchronization therapy: Comorbidity burden as predictor of mortality (Article)

2011-01-01T00:00:00Z

AimsComorbidity, such as myocardial infarction, diabetes, and renal failure, plays a pivotal role in the prognosis of a patient with arrhythmias. However, data on the prognostic impact of comorbiditiy in heart failure patients with cardiac resynchronization therapy and defibrillation (CRT-D) are scarce. The purpose of this study was to determine the impact of comorbidity on survival in CRT-D patients.Methods and resultsThe study population consisted of 463 heart failure patients who received a CRT-D between 1999 and 2008 in Rotterdam and Basel. The Charlson comorbidity index (CCI) is often used as an adjusting variable in prognostic models. The Cox proportional hazards analysis was performed to determine the independent effect of comorbidity on survival. During a median follow-up of 30.5 months, 85 patients died. Mortality rates at 1 and 7 years were 6.3 and 32.3. Cumulative incidence of implantable cardioverter defibrillator (ICD) therapy at 7 years was 50, and death without ICD therapy was observed in 9 of patients. At least three comorbid conditions were observed in 81 of patients. Patients who died had a higher CCI score compared with those who survived (3.9 ± 1.5 vs. 2.9 ± 1.5; P < 0.001). An age-adjusted CCI score <5 was a predictor of mortality (hazard ratio 3.69, 95 CI 2.066.60; P < 0.001) independent from indication for ICD therapy, and from ICD interventions during the clinical course.ConclusionComorbidity is often present in heart failure patients, and a high comorbidity burden was a significant predictor of mortality in CRT-D recipients. Comorbidity cannot predict appropriate ICD therapy. Death without prior ICD therapy occurs in a minor proportion of patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2010. For permissions please email: journals.permissionsoxfordjournals.org.2010The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that the original authorship is properly and fully attributed; the Journal, Learned Society and Oxford University Press are attributed as the original place of publication with correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals. permissionsoxfordjournals.org. © Published on behalf of the European Society of Cardiology. All rights reserved.

Effect of implantable cardioverter-defibrillator on left ventricular ejection fraction in patients with idiopathic dilated cardiomyopathy (Article)

2010-12-01T00:00:00Z

Current guidelines have indicated an implantable cardioverter-defibrillator (ICD) for patients with severe idiopathic dilated cardiomyopathy, for both primary and secondary prevention. Compared to coronary artery disease, the overall benefit has been smaller. A more refined risk assessment, using the left ventricular ejection fraction (LVEF) and prevention mode (primary/secondary), is still needed to guide ICD implantation. Patients included in 2 large ICD registers were analyzed regarding the appropriate therapies and improvement of LVEF, overall and in subgroups of prevention mode and LVEF <20% versus >20%. Overall, 349 patients were included; 70% were men, the mean age was 54 years, and the mean follow-up was 33 months. Cardiac resynchronization therapy (CRT) was used in 57%, and secondary prevention was present in 30%. ICD therapies were delivered to 33% of the patients, in most for ventricular tachycardia. Patients receiving an ICD for secondary prevention and non-CRT were more likely to have arrhythmic events (both p <0.05). The cumulative event rates at 5 years were 53% for secondary and 33% for primary prevention (p <0.001). Depending on the prevention mode and LVEF status (<20% vs >20%), the event rates ranged from 30% to 76%. The mean LVEF improved by 10%, independently of the stimulation mode (CRT 22% to 31%, non-CRT 26% to 35%; p <0.0001). A persistent improvement to >35% was seen in only 25% of CRT patients but in 45% of non-CRT patients (p = 0.004). In conclusion, the results from the present study have demonstrated that in patients with idiopathic dilated cardiomyopathy, the potential for LVEF improvement is considerable and that the rate of ICD interventions strongly depends on the prevention mode and LVEF. These findings could be the basis for additional risk stratification tools.

Shock as a determinant of poor patient-centered outcomes in implantable cardioverter defibrillator patients: Is there more to it than meets the eye? (Article)

2010-12-01T00:00:00Z

The medical benefits of the implantable cardioverter defibrillator (ICD) are well established, but ICD shocks are known to influence patient-centered outcomes. In this viewpoint, we examine the strength of the evidence as found in primary and secondary prevention trials that used quality of life as an outcome, and compare the influence of ICD shock with other factors (e.g., heart failure and psychological factors) as determinants of outcomes, with a view to providing recommendations for clinical practice and future research. Based on the large-scale primary and secondary prevention trials (i.e., CABG-PATCH, CIDS, AVID, AMIOVIRT, SCD-HeFT, MADIT-II, and DEFINITE), evidence for an association between ICD shocks and quality of life is mixed, with some indication that the influence of shocks may depend largely on the interval between shocks and assessment of quality of life. In order to improve the clinical management of ICD patients, we need to adopt a more rigorous and standardized methodology in future studies in order to be able to draw firm conclusions about the impact of ICD shocks on individual patients. We also need to acknowledge that the impact of shocks on psychological functioning and quality of life may not be as straightforward as previously assumed. Given that programming of the ICD is changing, leading to fewer shocks and improved quality of life, it may be timely to also examine the influence of other determinants (e.g., heart failure progression and the patient's psychological profile) of patient-centered outcomes both in research and in clinical practice.

Close connection between improvement in left ventricular function by cardiac resynchronization therapy and the incidence of arrhythmias in cardiac resynchronization therapy-defibrillator patients (Article)

2010-12-01T00:00:00Z

Aims The aim of this study was to determine the relationship between improved ejection fraction (EF) and occurrence of arrhythmias in patients with cardiac resynchronization therapy devices with defibrillator function (CRT-D). The hypothesis was that patients who experienced a marked improvement in EF also had fewer appropriate defibrillator interventions. Methods and results We analysed data of 270 patients from2 prospective registries with follow-up of ≥12 months and echocardiography performed ≥8 months after CRT-D implantation. The discriminator was whether left ventricular ejection fraction (LVEF) improved to >35 [cut-off for primary prevention implantable cardioverter-defibrillator (ICD) implantation]. Mean age was 61 ± 11 years, LVEF 22 ± 5, and follow-up 40 ± 22 months. Ischaemic cardiomyopathy was present in 48, and secondary prevention indication was present in 25. Implantable cardioverter-defibrillator interventions were delivered to 35 of patients. Echocardiography (20 ± 15 months after implantation) showed an improvement in LVEF from 22 (SD 5.4) to 30 (SD 9.8). Improvement to >35 was seen in 21 of patients. Those who improved to >35 had fewer ICD interventions than those who did not (23 vs.38; P-value 0.03). Analysing only patients with a primary prevention indication and stratifying again in patients with and without improvement of LVEF to >35, the latter had highly significant more ICD-therapies (6 vs. 31; P-value 0.0008).Conclusion Patients with CRT-D for primary prevention, whose LVEF improved to >35 during mid-term follow-up, are at low risk of first ICD therapies beyond year 1. If similar findings are reported in other patient cohorts, this might impact on decision-making at the time of battery depletion.

Effectiveness of prophylactic implantation of cardioverter-defibrillators without cardiac resynchronization therapy in patients with ischaemic or non-ischaemic heart disease: A systematic review and meta-analysis (Article)

2010-11-01T00:00:00Z

Aims: Much controversy exists concerning the efficacy of primary prophylactic implantable cardioverter-defibrillators (ICDs) in patients with low ejection fraction due to coronary artery disease (CAD) or dilated cardiomyopathy (DCM). This is also related to the bias created by function improving interventions added to ICD therapy, e.g. resynchronization therapy. The aim was to investigate the efficacy of ICD-only therapy in primary prevention in patients with CAD or DCM.Methods and results: Public domain databases, MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, were searched from 1980 to 2009 for randomized clinical trials of ICD vs. conventional therapy. Two investigators independently abstracted the data. Pooled estimates were calculated using both fixed-effects and random-effects models. Eight trials were included in the final analysis (5343 patients). Implantable cardioverter-defibrillators significantly reduced the arrhythmic mortality [relative risk (RR): 0.40; 95 confidence interval (CI): 0.27-0.67] and all-cause mortality (RR: 0.73; 95 CI: 0.64-0.82). Regardless of aetiology of heart disease, ICD benefit was similar for CAD (RR: 0.67; 95 CI: 0.51-0.88) vs. DCM (RR: 0.74; 95 CI: 0.59-0.93).Conclusions: The results of this meta-analysis provide strong evidence for the beneficial effect of ICD-only therapy on the survival of patients with ischaemic or non-ischaemic heart disease, with a left ventricular ejection fraction ≤35, if they are 40 days from myocardial infarction and ≥3 months from a coronary revascularization procedure.

Pre-implantation implantable cardioverter defibrillator concerns and Type D personality increase the risk of mortality in patients with an implantable cardioverter defibrillator (Article)

2010-10-01T00:00:00Z

Aims Little is known about the influence of psychological factors on prognosis in implantable cardioverter defibrillator (ICD) patients. We examined the influence of the distressed personality (Type D) and pre-implantation device concerns on short-term mortality in ICD patients. Methods and results Consecutively implanted ICD patients (N = 371; 79.5 men) completed the Type D Scale and the ICD Patient Concerns questionnaire prior to implantation and were followed up for short-term mortality. The prevalence of Type D was 22.4, whereas 34.2 had high levels of ICD concerns. The incidence of mortality was higher in Type D vs. non-Type D patients [13.3 vs. 4.92; hazard ratio (HR): 2.74; 95 confidence interval (CI): 1.24-6.03] and in patients with high vs. low levels of ICD concerns (11.0 vs. 4.5; HR: 2.38; 95 CI: 1.08-5.23). Type D personality (HR: 2.79; 95 CI: 1.25-6.21) and high levels of ICD concerns (HR: 2.38; 95 CI: 1.06-5.34) remained independent predictors of mortality in separate analyses, adjusting for sex, age, ICD indication, coronary artery disease, and shocks. Patients with clustering of both Type D personality and high levels of pre-implantation concerns (HR: 3.86; 95 CI: 1.64-9.10) had a poorer survival compared with patients with one or none of these risk markers in adjusted analysis. Shocks during the follow-up period were also associated with mortality (HR: 3.09; 95 CI: 1.36-7.04). Conclusion Patients with a distressed personality and high levels of pre-implantation device-related concerns had a poorer prognosis, independent of other risk markers including shocks. This subgroup of patients should be identified in clinical practice and would likely benefit from a combined distress management programme and cardiac rehabilitation.

Course of anxiety and device-related concerns in implantable cardioverter defibrillator patients the first year post implantation (Article)

2010-08-01T00:00:00Z

Aims Implantable cardioverter defibrillators (ICDs) are well accepted by most patients, but 25-33 of patients are anxious and report device-related concerns. Previous studies focused on prevalence rates and mean scores, whereas the course of anxiety over time is unknown in individual patients. We examined the trajectory of anxiety in ICD patients during a 1-year period and determinants of these trajectories. Methods and results Consecutive patients (N = 348) implanted with an ICD completed standardized measures of general anxiety and device-related concerns at five assessment occasions and the Type D Scale at baseline. Type D personality is defined by increased negative emotions and the inhibition of these emotions in social interactions. Seven trajectories were identified for state and trait anxiety and eight for device-related concerns. The course of the trajectories for general anxiety was stable over time, whereas device-related concerns showed more fluctuation, with a decrease in concerns generally spread out during the 1 year. Type D personality and social support were determinants of trajectory membership for general anxiety (all P ≤ 0.002), whereas Type D (P = 0.001), social support (P = 0.02), and ICD shock (P < 0.001) determined trajectory membership for device-related concerns. Conclusion The course of general anxiety in ICD patients was stable the first year post implantation, whereas device-related concerns fluctuated more. Type D personality and social support were determinants of trajectory membership for all outcomes, whereas ICD shock was related to device-related concerns only. A simple pre-implant screening may help identify patients at risk for high-distress trajectory membership. Published on behalf of the European Society of Cardiology.

An entirely subcutaneous implantable cardioverter-defibrillator (Article)

2010-07-01T00:00:00Z

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) prevent sudden death from cardiac causes in selected patients but require the use of transvenous lead systems. To eliminate the need for venous access, we designed and tested an entirely subcutaneous ICD system. METHODS: First, we conducted two shortterm clinical trials to identify a suitable device configuration and assess energy requirements. We evaluated four subcutaneous ICD configurations in 78 patients who were candidates for ICD implantation and subsequently tested the best configuration in 49 additional patients to determine the subcutaneous defibrillation thresh old in comparison with that of the standard transvenous ICD. Then we evaluated the longterm use of subcutaneous ICDs in a pilot study, involving 6 patients, which was followed by a trial involving 55 patients. RESULTS: The best device configuration consisted of a parasternal electrode and a left lateral thoracic pulse generator. This configuration was as effective as a transvenous ICD for terminating induced ventricular fibrillation, albeit with a significantly higher mean (±SD) energy requirement (36.6±19.8 J vs. 11.1±8.5 J). Among patients who received a permanent subcutaneous ICD, ventricular fibrillation was successfully detected in 100% of 137 induced episodes. Induced ventricular fibrillation was converted twice in 58 of 59 patients (98%) with the delivery of 65J shocks in two consecutive tests. Clinically significant adverse events included two pocket infections and four lead revisions. After a mean of 10±1 months, the device had successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia. CONCLUSIONS: In small, nonrandomized studies, an entirely subcutaneous ICD consistently detected and converted ventricular fibrillation induced during electrophysiological testing. The device also successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia. (ClinicalTrials.gov numbers, NCT00399217 and NCT00853645.).

Long-term outcome of alcohol septal ablation in patients with obstructive hypertrophic cardiomyopathy: A word of caution (Article)

2010-05-01T00:00:00Z

Background: The impact of alcohol septal ablation (ASA)-induced scar is not known. This study sought to examine the long-term outcome of ASA among patients with obstructive hypertrophic cardiomyopathy. Methods and Results: Ninety-one consecutive patients (aged 54±15 years) with obstructive hypertrophic cardiomyopathy underwent ASA. Primary study end point was a composite of cardiac death and aborted sudden cardiac death including appropriate cardioverter-defibrillator discharges for fast ventricular tachycardia/ ventricular fibrillation. Secondary end points were noncardiac death and other nonfatal complications. Outcomes of ASA patients were compared with 40 patients with hypertrophic cardiomyopathy who underwent septal myectomy. During 5.4±2.5 years, primary and/or secondary end points were seen in 35 (38%) ASA patients of whom 19 (21%) patients met the primary end point. The 1-, 5-, and 8-year survival-free from the primary end point was 96%, 86%, and 67%, respectively in ASA patients versus 100%, 96%, and 96%, respectively in myectomy patients during 6.6±2.7 years (log-rank, P=0.01). ASA patients had a ≈5-fold increase in the estimated annual primary end point rate (4.4% versus 0.9%) compared with myectomy patients. In a multivariable model including a propensity score, ASA was an independent predictor of the primary end point (unadjusted hazard ratio, 5.2; 95% CI, 1.2 to 22.1; P=0.02 and propensity score-adjusted hazard ratio, 6.1; 95% CI, 1.4 to 27.1; P=0.02). Conclusions: This study shows that ASA has potentially unwanted long-term effects. This poses special precaution, given the fact that ASA is practiced worldwide at increasing rate. We recommend myectomy as the preferred intervention in patients with obstructive hypertrophic cardiomyopathy.

Editorial: Defibrillation threshold testing at implantation: Can we predict the patient with a high defibrillation threshold? (Article)

2010-03-01T00:00:00Z

Posttraumatic stress in implantable cardioverter defibrillator patients: The role of pre-implantation distress and shocks (Article)

2010-01-01T00:00:00Z

Prediction of Appropriate Defibrillator Therapy in Heart Failure Patients Treated With Cardiac Resynchronization Therapy (Article)

2010-01-01T00:00:00Z

The necessity of implantable cardioverter-defibrillator (ICD) implantation in patients with systolic heart failure (HF) who undergo cardiac resynchronization therapy (CRT) may be questioned. The aim of this study was to identify patients at low risk for sustained ventricular arrhythmia. One hundred sixty-nine consecutive patients with HF (mean age 60 ± 12 years, 125 men, 73% in New York Heart Association class III) referred for CRT and prophylactic, primary prevention ICD implantation underwent baseline clinical and echocardiographic assessment and regular device follow-up. The primary study end point was appropriate ICD therapy. During a mean follow-up period of 654 ± 394 days, 35 patients (21%) had sustained ventricular arrhythmias requiring appropriate ICD therapy. Of the 3 patients who experienced sudden cardiac death, 2 had been treated with appropriate ICD therapy before sudden cardiac death. In a multivariate model, only history of nonsustained ventricular tachycardia (p = 0.001), a severely (<20%) decreased left ventricular ejection fraction (p = 0.001), and digitalis therapy (p = 0.08) independently predicted appropriate ICD therapy. Patients with 0 (n = 46), 1 (n = 36), 2 (n = 73), and 3 (n = 14) risk factors for appropriate ICD therapy had a 7%, 14%, 27%, and 64% and 0%, 6%, 10%, and 43% incidence of appropriate ICD therapy for ventricular arrhythmias and for rapid ventricular tachycardia or ventricular fibrillation, respectively. In conclusion, apart from commonsense considerations (age and significant co-morbidities), ICD addition seems ineffective in CRT patients without nonsustained ventricular tachycardia, digoxin therapy, and severely reduced left ventricular systolic function.

Rationale and design of WEBCARE: A randomized, controlled, web-based behavioral intervention trial in cardioverter-defibrillator patients to reduce anxiety and device concerns and enhance quality of life (Article)

2009-12-23T00:00:00Z

Background: The implantable cardioverter defibrillator (ICD) is generally well accepted, but 25-33% of patients experience clinical levels of anxiety, depression, and impaired quality of life (QoL) following implantation. Few trials in ICD patients have investigated whether behavioral intervention may mitigate the development of these adjustment problems. We present the rationale and study design of the WEB-based distress management program for implantable CARdioverter dEfibrillator patients (WEBCARE) trial.Methods: WEBCARE is a multi-center, multi-disciplinary, randomized, controlled behavioral intervention trial designed to examine the effectiveness of a web-based approach in terms of reducing levels of anxiety and device concerns and enhancing QoL. Consecutive patients hospitalized for the implantation of an ICD will be approached for study participation while in hospital and randomized to the intervention arm (n = 175) versus usual care (n = 175) at baseline (5-10 days post implantation). Patients will complete assessments of patient-centered outcomes at baseline, 14, 26, and 52 weeks after implantation. Patients randomized to the intervention arm will receive a 12-week web-based behavioral intervention starting 2 weeks after implantation. Primary endpoints include (ii) patient-centered outcomes (i.e., anxiety, depression, ICD acceptance, QoL); (iii) health care utilization; and (iiii) cost-effectiveness. All primary endpoints will be assessed with standardized and validated disease-specific or generic questionnaires. Secondary endpoints include (iii) cortisol awakening response; and (iiii) ventricular arrhythmias.Discussion: WEBCARE will show whether a behavioral intervention using a web-based approach is feasible and effective in reducing anxiety and ICD concerns and improving QoL in ICD patients.

Analysis of implantable defibrillator longevity under clinical circumstances: Implications for device selection (Article)

2009-10-01T00:00:00Z

Introduction: Information about implantable cardioverter-defibrillator (ICD) longevity is mostly calculated from measurements under ideal laboratory conditions. However, little information about longevity under clinical circumstances is available. This survey gives an overview on ICD service times and generator replacements in a cohort of consecutive ICD patients. Methods: Indications for replacement were classified as a normal end-of-service (EOS), premature EOS, system malfunction, infection and device advisory, or recall actions. From the premature and normal EOS group, longevity from single-chamber (SC), dual-chamber (DC), and cardiac resynchronization therapy defibrillator (CRT-D), rate-responsive (RR) settings, high output (HO) stimulation, and indication for ICD therapy was compared. Differences between brands were compared as well. Results: In a total of 854 patients, 203 ICD replacements (165 patients) were recorded. Premature and normal EOS replacements consisted of 32 SC, 98 DC and 24 CRT-D systems. Longevity was significantly longer in SC systems compared to DC and CRT-D systems (54 ± 19 vs. 40 ± 17 and 42 ± 15 months; P = 0.008). Longevity between non-RR (n = 143) and RR (n = 11) settings was not significantly different (43 ± 18 vs. 45 ± 13 months) as it also was not for HO versus non-HO stimulation (43 ± 19 vs. 46 ± 17 months). Longevity of ICDs was not significantly different between primary and secondary prevention (42 ± 19 vs. 44 ± 18 months). The average longevity on account of a device-based EOS message was 43 ± 18 months. Average longevity for Biotronik (BIO, n = 72) was 33 ± 10 months, for ELA Medical (ELA, n = 12) 44 ± 17 months, for Guidant (GDT, n = 36) 49 ± 12 months, for Medtronic (MDT, n = 29) 62 ± 22 months, and for St. Jude Medical (SJM, n = 5) 31 ± 9 months (P < 0.001). Conclusion: SC ICD generators had a longer service time compared to DC and CRT-D systems. No influence of indication for ICD therapy and HO stimulation on generator longevity was observed in this study. MDT ICDs had the longest service time. (PACE 2009; 1276-1285).

The ischemic etiology of heart failure in diabetics limits reverse left ventricular remodeling after cardiac resynchronization therapy (Article)

2009-09-01T00:00:00Z

Aim of the Study: The aim of this study was to evaluate reverse volumetric left ventricular (LV) remodeling after cardiac resynchronization therapy (CRT) in patients with heart failure (HF) with vs. without diabetes mellitus (DM). Methods: The study comprised 130 consecutive patients with HF (mean age, 61±12 years) who underwent CRT. Thirty patients (23%) had DM [mean glycated haemoglobin (HbA1c), 7.2±3.4%; 13 (43%) on insulin therapy]. Echocardiography, including tissue Doppler measurements, was performed before CRT and between 3 and 6 months after CRT. Echocardiographic response was defined as a >15% reduction in LV end-systolic volume (ESV). Results: Patients with DM had more often hypertension (60% vs. 29%, P<.05) and ischemic HF etiology (87% vs. 51%, P<.05), but similar pre-CRT echocardiographic findings. After CRT, patients with DM had equal reductions in QRS duration and lateral-to-septal mechanical delay, but less improvement in LV ESV, mitral annular tissue velocity, the myocardial performance (or Tei) index and the E/E′ ratio (ratio of early transmitral peak filling velocity to early mitral annular peak diastolic velocity, an indicator of LV filling pressure). Patients without reverse volumetric LV remodeling had more often DM [hazard ratio (HR), 1.897; P=.042] and an ischemic HF etiology (HR, 2.308; P=.006). An ischemic HF etiology (HR, 2.119; P=.018) was the only independent predictor of poor reverse volumetric LV remodeling. Conclusion: Ischemic etiology of HF is an independent predictor of poor echocardiographic response to CRT. Patients with DM and HF have a relatively poor echocardiographic response to CRT most probably due to a high incidence of ischemic etiology of HF.

A viewpoint on the impact of device advisories on patient-centered outcomes (Article)

2009-08-01T00:00:00Z

Device advisories due to potential hardware failure comprise one of the downsides of implantable cardioverter defibrillator (ICD) therapy. The impact of advisories on patient-centered outcomes has largely been overlooked. We examined the impact of ICD advisories on patient-centered outcomes via a systematic literature review. PubMed was searched in the period from 1980 to present using a combination of at set of a priori search terms. The reference lists of the included papers were searched by hand. A total of six studies were identified. All advisories were Class I, Class II, or a combination. The sample size across studies varied between 30 and 86 patients subject to an advisory; four of six studies used a case-control design and two of six a prospective study design. There was considerable variability between notification of the advisory and assessment of the patient-centered outcomes, ranging from 1 to 24 months. A mixture of generic and disease-specific patient-centered outcome measures was used. The evidence for an impact on device advisories was mixed, with the two prospective studies showing an increase in anxiety over time, whereas none of the larger case-control studies found a difference in patient-centered outcomes between cases and controls. Evidence for an impact of device advisories on patient-centered outcomes is mixed. In order to incorporate a patient-centered approach in clinical care, patient-centered outcomes should form part of standard clinical practice and if available the assessments entered into ICD registries. Such registries would provide important insights into the impact of ICD advisories on patients' well being.

Usefulness of Left Ventricular Systolic Dyssynchrony by Real-Time Three-Dimensional Echocardiography to Predict Long-Term Response to Cardiac Resynchronization Therapy (Article)

2009-06-01T00:00:00Z

Real-time 3-dimensional echocardiography (RT3DE) allows simultaneous timing of regional volumetric changes as a net result of longitudinal, radial, circumferential left ventricular (LV) contraction, hence LV systolic dyssynchrony. We sought to examine real-time 3-dimensional echocardiographically derived dyssynchrony for prediction of long-term response to cardiac resynchronization therapy (CRT) in a prospective study. Ninety consecutive patients with heart failure (mean age 60 ± 12 years, 73% men, New York Heart Association class III in 97%) underwent clinical and echocardiographic assessments at baseline and at 12 months after CRT including real-time 3-dimensional echocardiographically derived LV systolic dyssynchrony index. The systolic dyssynchrony index (SDI) was defined as the SD of time to minimum systolic volume of the 16 LV segments, expressed in percent RR duration. CRT response was defined as a >15% decrease in LV end-systolic volume on real-time 3-dimensional echocardiogram. After 12 months of CRT, 68 patients (76%) were responders. Feasibility of the SDI was 94%. An SDI >10% predicted CRT response with good sensitivity (96%), specificity (88%), positive likelihood ratio (8), and negative likelihood ratio (0.05). Patients with an SDI >10% had mean change (-21%, -31%, 39% vs -13%, -10%, 10%) in LV end-diastolic volume, LV end-systolic volume, and LV ejection fraction, respectively, compared with baseline versus patients with an SDI <10% (p <0.01). Mean acquisition and analysis duration of single-patient RT3DE was 8 minutes (range 6 to 13). Interobserver variabilities of LV end-systolic volume and SDI were 5% and 11%, respectively. In conclusion, RT3DE provides accurate identification of reverse volumetric LV remodeling after CRT. From these accurate volumetric data, RT3DE provides more intuitive assessment of dyssynchrony and response to CRT as a simple, reproducible, and fast technique. CRT can be individually tailored using RT3DE and seems very effective in patients with heat failure with real-time 3-dimensional echocardiographic evidence of dyssynchrony.

Quantification of Left Ventricular Systolic Dyssynchrony by Real-Time Three-Dimensional Echocardiography (Article)

2009-03-01T00:00:00Z

Objective: To assess real-time 3-dimensional echocardiography (RT3DE)-derived left ventricular (LV) systolic dyssynchrony parameters: (1) normal values, (2) characteristics in patients with heart failure (HF) and a wide or narrow QRS complex, (3) interobserver and intraobserver variability with current state of the art RT3DE hardware and software technology, and (4) incremental value in patients with HF who receive cardiac resynchronization therapy (CRT). Methods: The study involved 84 patients with HF (mean age 54 ± 15 years, 50 men) and 60 healthy volunteers (mean age 41 ± 15 years, 36 men). Semiautomated LV endocardial border tracking was used to calculate regional time-to-minimum systolic volume and to generate parametric maps and the systolic dyssynchrony index (SDI), defined as the standard deviation of time-to-minimum systolic volume of the 16 LV segments expressed in percentage of R-R duration. Results: The volume rate of the RT3DE datasets in patients with HF was 31 ± 9 Hz (range 15-42 Hz). The normal value of the SDI was 4.1% ± 2.2% (range <1.0%-8.9%). Patients with HF had a larger SDI (13.4% ± 8.1%, P < .001). There was only a weak correlation (r2 = 0.07, P < .05) between the QRS duration and the SDI. Interobserver interclass correlation and variability of the SDI depended on image quality (good: 0.993 and 9%, moderate: 0.907 and 16%, respectively). Interobserver agreement for the identification of the most delayed LV segment depended on image quality (good: 90%, moderate: 76%). Thirty-nine patients underwent CRT. At the 12-month follow-up, LV volumetric responders had a significant reduction in the SDI (16.3% ± 3.3% to 7.7% ± 2.4%, P < .001). Conclusion: With state of the art technology, RT3DE allows reproducible assessment of LV systolic dyssynchrony, which may be useful to identify potential responders to CRT.

Analysis of 57,148 transmissions by remote monitoring of implantable cardioverter defibrillators (Article)

2009-03-01T00:00:00Z

Introduction: Remote monitoring of implantable cardioverter defibrillators (ICD) is designed to decrease the number of ambulatory visits and facilitate the early detection of adverse events. We examined the impact of remote monitoring on clinical workload by a comprehensive analysis of transmitted events. Methods: The study population consisted of 146 recipients of ICD capable of remote monitoring. Data were transmitted daily or in case of pre-specified events (e.g., arrhythmia, out-of-range lead and/or shock impedance). Transmitted events were classified as clinical (disease-related) or system-related. Event rates/patient/month were calculated and compared according to events classification and clinical groups. Results: During a mean follow-up of 22 ± 16 months, a total of 57,148 remote transmissions were recorded. Of these transmissions, 1009 (1.8%) were triggered by a pre-specified event, including induced ventricular fibrillation (VF) episodes during defibrillation threshold testing. The median number of events/patient/month was 0.14. Event rates were similar in patients with primary and secondary prevention indications for ICD (0.15 vs. 0.11). After exclusion of the induced VF episodes, 5.6% of transmitted events were classified as system-related and 94.4% as clinical. The median number of clinical events/patient/month was 0.023. The clinical event-free rates were 62% and 45%, at 1 and 4 years, respectively. Conclusion: Remote monitoring of ICD patients is feasible. Despite the large number of data transmissions, remote monitoring imposed a minimal additional burden on the clinical workload. The rate of triggered data transmissions by critical events was, relatively, very low.

Increased anxiety in partners of patients with a cardioverter- defibrillator: The role of indication for ICD therapy, shocks, and personality (Article)

2009-02-01T00:00:00Z

Background: The partner of the implantable cardioverter-defibrillator (ICD) patient serves as an important source of support for the patient, which may be hampered if the partner experiences increased distress. We examined (1) potential differences in anxiety and depressive symptoms in ICD patients compared to their partners, and (2) the extent to which the partner's personality is a more important determinant of partner distress than patient clinical characteristics, using a prospective design. Methods: Consecutively implanted ICD patients (n = 196) and their partners (n = 196) completed a set of psychological questionnaires at baseline and 6 months after implantation. Results: Analysis of variance with repeated measures showed that partners had significantly higher levels of anxiety compared to patients (F(1,390) = 16.431; P < 0.001) but not depressive symptoms (F(1,390) = 0.186; P = 0.67). There was a significant overall reduction in anxiety (F(1,390) = 79.552; P < 0.001) and depressive symptoms (F(1,390) = 39.868; P < 0.001) over 6 months, with group (i.e., patient vs partner) exerting a stable effect on anxiety (F(1,390) = 0.966; P = 0.33) and depressive symptoms (F(1,390) = 0.025; P = 0.87). These results remained in adjusted analysis. Determinants of anxiety and depressive symptoms in partners included secondary prophylaxis in patients (Ps < 0.001-0.002), Type D personality of the partner (Ps < 0.001-0.001), secondary prophylaxis by shock interaction (P = 0.002; anxiety only), and secondary prophylaxis by Type D interaction (Ps = 0.001-0.003). Conclusions: Partners had higher levels of anxiety but not depression than ICD patients. Partner distress could be attributed not only to the partner's personality, but also to patient clinical characteristics, primarily secondary prophylaxis for ICD therapy. These results indicate that information on the clinical characteristics of the patient in addition to partner characteristics may help identify partners at risk of distress.

One year follow-up after cryoballoon isolation of the pulmonary veins in patients with paroxysmal atrial fibrillation (Article)

2008-11-01T00:00:00Z

Aims: Pulmonary vein isolation (PVI) with cryoenergy delivered through a balloon is a new approach in the treatment of atrial fibrillation (AF), but long-term follow-up is lacking. The aim of this study was to provide insight in the success rate and the incidence of recurrences. Methods and results: Patients with symptomatic AF despite anti-arrhythmic drugs (AADs) were treated with cryoballoon PVI. Daily transtelephonic ECG monitoring, 24 h Holter-ECG, and an arrhythmia-focused questionnaire were used to document AF. One hundred and forty-one patients completed a follow-up of 457 ± 252 days. Before ablation, Holter-ECG showed AF in 45%, including 16% continuous AF throughout the recording. Event recording revealed a median AF burden of 26%. The questionnaire showed a median of weekly AF complaints lasting for hours. All but one patient had successful PVI with a single procedure. After ablation, AF (defined as lasting for more than 30 s) was seen in 11% of Holter-ECGs, with 1% continuous AF. The event recording showed an AF burden of 9%. The median patient reported no more AF-related symptoms. Recurrence during the first 3 months was predictive for later recurrence. A second procedure was performed in 24 patients. The freedom of AF was 59% without AADs after 1,2 procedures. Four right phrenic nerve paralyses occurred, all resolving within 6 months. No PV stenoses were observed. Conclusion: Pulmonary vein isolation with a cryothermal balloon is an effective treatment for paroxysmal AF, resulting in a clinical success rate comparable to studies involving radiofrequency ablation. Temporary right phrenic nerve paralysis is the most important complication.

New-onset atrial fibrillation is an independent predictor of in-hospital mortality in hospitalized heart failure patients: Results of the EuroHeart Failure Survey (Article)

2008-07-01T00:00:00Z

Aims: The prognostic significance of atrial fibrillation (AF) in hospitalized patients with heart failure (HF) remains poorly understood. To evaluate in what way AF and its different modes of presentation affect the in-hospital mortality in patients admitted with HF. Methods and results: The EuroHeart Failure Survey was conducted to ascertain how hospitalized HF patients are managed in Europe. The survey enrolled patients over a 6-week period in 115 hospitals from 24 countries. For this analysis, patients were categorized into three groups according to the type of AF, previous AF (patients known to have had AF prior to admission), new-onset AF (no previous AF with AF diagnosed during hospitalization), and no AF (no previous AF and no AF during hospitalization). Clinical variables, duration of hospitalization, and in-hospital survival status were assessed and compared among groups. Of the 10 701 patients included in the survey; 6027 (57%) had no AF, 3673 (34%) had previous AF, and 1001 (9%) had new-onset AF. Patients with new-onset AF had a longer stay in the intensive care unit (ICU) when compared with previous AF and no AF patients (mean 2.6 ± 5.3, 1.2 ± 3.5, and 1.5 ± 4.1 days, respectively; P < 0.001). In-hospital mortality was higher among patients with new-onset AF when compared with previous AF or no AF patients (12, 7, and 7% respectively; P < 0.001). After adjusting for multiple clinical variables, new-onset AF (not previous AF) was an independent predictor of in-hospital mortality (odds ratio 1.53, 95% CI 1.1-2.0). Conclusion: In hospitalized patients with HF, new-onset AF is an independent predictor of in-hospital mortality and a longer ICU and hospital stay.

Triggered alerts to detect lead malfunction: One step beyond (Article)

2008-07-01T00:00:00Z

Symptoms versus objective rhythm monitoring in patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation (Article)

2008-06-01T00:00:00Z

Background: Pulmonary vein (PV) ablation is a treatment option for patients with atrial fibrillation (AF). The efficacy of treatment is often assessed by the evaluation of symptoms. However, a high proportion of AF episodes occur in the absence of symptoms as observed in pharmacological treated patients. The purpose of this study was to assess the association of symptoms and AF in patients who underwent PV ablation for the treatment of paroxysmal AF. Methods: All consecutive patients scheduled for PV ablation received an event recorder 1 month prior to the ablation for the period of 4 months. Event strips were sent by telephone on a daily basis, and in case the patient suffered palpitations or other symptoms believed to be related to the arrhythmia. Results: Forty-one patients (7 females; mean age 52 years (range 24 to 71 years)) sent a total of 3046 event strips (735 before ablation; 2311 after ablation). Before ablation, a total amount of 244 event strips were obtained of which were 85 (35%) were asymptomatic. After ablation, a total amount of 254 AF event strips were obtained of which 164 were asymptomatic (65%). Correlation between symptoms and rhythm was often absent during AF. Conclusion: Our data demonstrate that for the evaluation of effectiveness of PV ablation, the lack of symptoms during follow-up is not a valid indication. Objective rhythm monitoring in order to detect asymptomatic AF should be performed.

Prevention of inappropriate therapy in implantable defibrillators: A meta-analysis of clinical trials comparing single-chamber and dual-chamber arrhythmia discrimination algorithms (Article)

2008-04-25T00:00:00Z

Introduction: A proposed benefit of dual-chamber arrhythmia discrimination is a reduction in inappropriate therapy in implantable cardioverter-defibrillators (ICDs). The aim of this meta-analysis was to establish whether dual-chamber arrhythmia discrimination algorithms reduce inappropriate device therapy. Methods and results: Public domain databases, MEDLINE, EMBASE, and Cochrane Register of Controlled Trials, were searched from 1996 to 2006. Two investigators abstracted data independently. Pooled estimates were calculated using both fixed-effects and random-effects models. We retrieved 5 prospective studies comparing dual-chamber with single-chamber arrhythmia discrimination, accumulating data on 748 patients. Pooled per-patient based analysis demonstrated that the number of patients receiving inappropriate ICD therapy was not different between single- and dual-chamber devices (odds ratio [OR] 1.23; 95% CI, 0.83 to 1.81; p = 0.31). Per-episode based analysis demonstrated a favoring benefit for dual-chamber arrhythmia discrimination (OR 0.64; 95% CI, 0.52 to 0.78; p < 0.001). A mean reduction of 1.1 inappropriately treated atrial episodes per patient was observed with dual-chamber arrhythmia discrimination (p < 0.001). Conclusions: Dual-chamber arrhythmia discrimination is associated with a reduction in the number of inappropriate treated episodes. The number of patients who experience inappropriate therapy is not reduced by dual-chamber discrimination.

Reverse of Left Ventricular Volumetric and Structural Remodeling in Heart Failure Patients Treated With Cardiac Resynchronization Therapy (Article)

2008-03-01T00:00:00Z

Patients with heart failure and mechanical dyssynchrony suffer a progressive increase in left ventricular (LV) mass and asymmetrical regional hypertrophy with eventual poor prognosis. The present study sought to investigate whether cardiac resynchronization therapy (CRT) could reverse these abnormalities. The study included 66 consecutive heart failure patients who received CRT. All patients underwent serial evaluation before, 3 months after, and 12 months after CRT. At 12 months after CRT, 50 patients (76%) were echocardiographic volumetric responders, defined as a >15% reduction in LV end-systolic volume. LV end-systolic volume was decreased from 214 ± 97 ml to 179 ± 88 ml at 3 months and was further decreased to 158 ± 86 ml at 12 months after CRT (all p <0.01). LV ejection fraction was improved from 18% ± 4% to 28% ± 7% (p <0.001) at 3 months without further change at 12 months after CRT. LV mass was reduced from 242 ± 52 g to 222 ± 45 g at 3 months and was further reduced to 206 ± 50 g at 12 months after CRT (all p <0.01). Improvement of LV geometry was seen as improvements of the end-diastolic (1.64 ± 0.14 vs 1.77 ± 0.17, p <0.001) and the end-systolic (1.63 ± 0.14 vs 1.99 ± 0.22, p <0.001) sphericity indexes, respectively, at 3 months, without further significant changes at 12 months after CRT. Volumetric responders had a reduction in LV mass from 240 ± 50 to 210 ± 38 at 3 months, and LV mass was further reduced to 186 ± 37 g at 12 months after CRT (all p <0.01). In contrast, nonresponders had a progressive increase in LV mass from 248 ± 59 g to 258 ± 54 g at 3 months, and LV mass was further increased to 269 ± 60 g at 12 months after CRT (all p <0.05). Likewise, only in volumetric responders, regression of the asymmetric hypertrophy of the lateral wall was noted. In conclusion, CRT results in not only volumetric improvement but also in true reverse LV structural remodeling, evidenced by progressive reduction in LV mass and restoration of regional wall symmetry.

Clustering of device-related concerns and type D personality predicts increased distress in ICD patients independent of shocks (Article)

2008-01-01T00:00:00Z

Background: This study examined the impact of clustering of device-related concerns and Type D personality on anxiety and depressive symptoms during a six-month period and the clinical relevance of shocks, implantable cardioverter defibrillator (ICD) concerns, and Type D. Methods: Consecutively implanted ICD patients (n = 176) completed questionnaires at baseline and six months and were divided into four risk groups: (1) No risk factors (neither ICD concerns nor Type D); (2) ICD concerns only; (3) Type D only; (4) Clustering (both ICD concerns and Type D). Results: The prevalence of Type D and concerns were 21.6% and 34.7%. Analysis of variance for repeated measures showed a reduction in anxiety over time (P < 0.001), with the risk groups exerting a stable (P = 0.14) but differential effect (P < 0.001); the highest level was seen in the clustering group. Similar results were found for depression, although depressive symptoms did not decrease (P = 0.08) and the impact of clustering was less clear. These results were confirmed in adjusted analysis, with shocks (P = 0.024) also being associated with anxiety but not depression. The impact of ICD concerns and Type D personality on anxiety and depression at baseline and six months was large (≥0.8) compared to negligible to moderate for shocks (0.0-0.6). Conclusions: ICD patients with psychosocial risk factor clustering had the highest level of anxiety, whereas the pattern for depression was less consistent. Shocks influenced outcomes, but the impact was smaller compared to ICD concerns and Type D personality. It may be timely to expand the focus beyond shocks when seeking to identify ICD patients at risk for adverse clinical outcome due to their psychological profile.

Predictors of Cardiac Events After Cardiac Resynchronization Therapy With Tissue Doppler-Derived Parameters (Article)

2007-12-01T00:00:00Z

Background: To evaluate the prognostic value of tissue Doppler imaging (TDI)-derived parameters (E/E′ ratio and Tei index) in heart failure (HF) patients who underwent cardiac resynchronization therapy (CRT). Methods and Results: The study comprised 74 consecutive HF patients (mean age 60 ± 11 years) who underwent CRT. Echocardiography including TDI measurements was performed in all patients at baseline and 3 months after CRT. During a median follow-up period of 720 days (range 210 to 1020 days), 21 patients (28%) had events (8 deaths, and hospitalization for HF in the remaining 13). From the baseline clinical and echocardiography data, univariable Cox-regressions analysis revealed that only diabetes (hazard ratio [HR] 3.703, P < .01), E/A ratio (HR 3.492, P < .001), and E/E′ ratio (HR 1.130, P < .001) were predictors for cardiac events. From the 3-month follow-up data, the E/A ratio (HR 2.988, P < .005), E/E′ ratio (HR 1.170, P < .001), left ventricular ejection fraction (HR 0.835, P < .01), deceleration time (HR 0.977, P < .05), and the Tei index (HR 15.784, P < .001) were predictors for cardiac events. After multivariable analysis, only diabetes (HR 5.544, P < .05), the 3-month E/E′ ratio (HR 1.229, P < .001), and change in Tei index (HR 32.174, P < .001) were independent predictors for cardiac events. Patients with a high baseline and 3-month follow-up E/E′ ratio had an 88% cardiac event rate. Conclusions: The Tei index and E/E′ ratio are independent predictors of poor response and cardiac events after CRT.

Pulmonary vein isolation using an occluding cryoballoon for circumferential ablation: Feasibility, complications, and short-term outcome (Article)

2007-09-01T00:00:00Z

Aims: To assess safety, feasibility and short term outcome of pulmonary vein (PV) isolation in paroxysmal atrial fibrillation (AF) with a cryoballoon. Methods: We consecutively treated 57 patients with a double lumen 23 or 28 mm cryoballoon. The acute results, complications and follow-up over the first three months were analysed, using a comprehensive and intensive follow-up period. Results: During 57 procedures, 185 of 220 targeted PV's were successfully isolated using the cryoballoon (84%) (balloon group, 33 patients). In 33 veins (15%) an additional segmental isolation (hybrid group, 24 patients) was necessary with a standard cryocatheter to achieve isolation. The average procedure times were respectively 211 ± 108 and 261 ± 83 minutes (NS), the average fluoroscopy times 52 ± 36 and 66 ± 33 minutes (NS). The number of balloon applications did not differ between both groups: respectively a median 9 (4-18) and 10 (5-17) (NS). We observed four phrenic nerve paralysis after ablation of the right superior PV: two resolved immediately after cessation of the cryoenergy, one recovered after 3 months, one persisted up to 6 months. A daily transtelephonic rhythm recording showed a significant drop in mean AF burden from 24% to 10%, 8% and 5% during the three consecutive months of follow-up (p < 0.01 versus baseline). No differences were observed between the treatment groups. 34 patients (60%) were completely free from AF after a single procedure. Conclusions: Balloon cryoablation of the pulmonary veins with additional segmental isolation if necessary, is a good approach for patients presenting with paroxysmal AF, showing a significant reduction in AF burden after a single procedure. The major complication seems to be phrenic nerve paralysis after ablation of the right superior PV, but this is potentially reversible over several months.

Baseline Predictors of Cardiac Events After Cardiac Resynchronization Therapy in Patients With Heart Failure Secondary to Ischemic or Nonischemic Etiology (Article)

2007-08-01T00:00:00Z

We evaluated the value of baseline parameters derived from tissue Doppler imaging (TDI) for event prediction in patients with heart failure (HF) secondary to ischemic and nonischemic cause who underwent cardiac resynchronization therapy (CRT). Seventy-four consecutive patients with HF (mean age 59 ± 11 years) underwent CRT. Baseline clinical parameters included New York Heart Association class, 6-minute walking distance, HF cause, and diabetes. TDI-derived parameters included lateral and septal E/E′ ratios defined as peak early left ventricular (LV) filling velocity (E wave) to TDI-derived peak early diastolic velocity of the mitral annulus (E′ wave). During a median follow-up of 720 days, 21 patients (28%) had cardiac death or hospitalization for HF. These patients more often had an ischemic cause (p <0.05), diabetes (p <0.05), and restrictive filling (p <0.001), less often had LV dyssynchrony (p <0.05), and had higher septal and lateral E/E′ ratios (p <0.001 for the 2 comparisons). In a multivariable model using a forward selection algorithm, only the lateral E/E′ ratio remained an independent predictor of cardiac outcome. After 3 months of CRT, TDI-derived systolic mitral annular systolic and diastolic velocities improved significantly in nonischemic patients for the septal and lateral sides. In contrast, in ischemic patients no significant improvements were seen. Significant improvements were seen in septal and lateral E/E′ ratios in ischemic and nonischemic patients. However, the improvement in lateral E/E′ ratio was significantly less and absolute 3-months E/E′ ratios were worse in ischemic patients. In conclusion, baseline lateral E/E′ ratio is an independent predictor for cardiac events in patients with HF treated with CRT. The worse clinical outcome in ischemic patients may be due to failure of improvement in systolic and diastolic mitral annular velocities after CRT, resulting in a less pronounced improvement in LV filling pressures as demonstrated by this E/E′ ratio.

Type-D personality but not implantable cardioverter-defibrillator indication is associated with impaired health-related quality of life 3 months post-implantation (Article)

2007-08-01T00:00:00Z

Aims: Little is known about the impact of ICD indication (primary vs. secondary) on health-related quality of life (HRQL). Indication may also interact with psychological factors, such as personality. Using a prospective design, we examined whether ICD indication and type-D personality (i.e. experiencing increased negative emotions paired with emotional non-expression) serve as modulators of HRQL at baseline and 3 months post-implantation. Methods and results: Consecutively implanted ICD patients (n = 154) completed the Type-D Scale (DS14) at baseline and the Short-Form Health Survey 36 (SF-36) at baseline and 3 months. Of all patients, 82 (53%) received an ICD due to prophylactic reasons; the prevalence of type-D was 23%. Indication had no influence on HRQL (P = 0.75). Further stratification by personality showed a main effect for type-D personality (P < 0.001), with type-D patients generally experiencing poorer HRQL; there was no main effect for indication (P = 0.45) nor was the interaction effect indication by type-D significant (P = 0.22). There was a significant improvement in HRQL over time (P = 0.001). Type-D remained an independent predictor of impaired HRQL, adjusting for clinical factors and shocks during follow-up (P < 0.001). However, in adjusted analysis there was no longer a significant change in HRQL over time (P = 0.099). Conclusion: Type-D personality but not ICD indication was associated with impaired HRQL at the time of implantation and at 3 months. In the quest for enhancing risk stratification in clinical practice, personality factors, such as type-D, should not be ignored, as both type-D and poor HRQL have been associated with increased risk of mortality in cardiac patients.

A grateful heart (Article)

2007-07-01T00:00:00Z

Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy (Article)

2007-02-01T00:00:00Z

Aims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixty patients (72% males, mean age 59 ± 10 years) who were referred for CRT according to the ACC/ESC guidelines were enrolled in the study. All patients underwent spectral PW-TDI before and 1 year after CRT. Two left ventricular (LV) dyssynchrony time intervals, TOand TP(time to onset and peak of LV myocardial velocity, respectively), LSD were recorded. Left ventricular dyssynchrony was defined as LSD ≥60 ms. Clinical response was defined as an improvement in >1 NYHA class plus improvement in 6-min walk distance (6MWD) ≥25%, echocardiographic response was defined as a ≥15% reduction in LV end-systolic volume (LV-ESV). One year after CRT, 50 patients (83%) were clinical responders and 47 patients (78%) were echocardiographic responders. Both TOand TPLV dyssynchrony indices failed to predict echocardiographic CRT outcome. In addition, there were no significant differences between 'synchronous' and 'dyssynchronous' patient populations at baseline or follow-up in either clinical (NYHA class and 6MWD) or echocardiographic (LV ejection fraction, LV end-diastolic, and end-systolic) variables. Conclusion: The great majority of patients referred for CRT benefit clinically from it. However, spectral PW-TDI failed to predict CRT outcome. When PW-TDI dyssynchrony was applied for selection of proper CRT patients, up to 80-86% of the patients with synchronous LSD that had proven clinical and echocardiographic benefit from CRT would have been denied CRT.

Implantable defibrillator therapy: more than defibrillation... (Doctoral Thesis)

2005-04-27T00:00:00Z

During the past 25 years, the implantable cardioverter-defibrillator (ICD) has evolved from the treatment of last resort to the gold standard for patients at high risk for lifethreatening ventricular tachyarrhythmias. Patients at high risk include those who survived life-threatening ventricular tachyarrhythmias, and patients with cardiac diseases who carry an increased risk for these tachyarrhythmias. We performed a clinical assessment during implantation and follow-up of our patients in Rotterdam. Part I Prognosis and follow-up of patients with an ICD In Chapter 1, the clinical benefit of ICD therapy, survival, and adverse events of patients who received an ICD at the Erasmus MC Rotterdam are described. Our data confirm the benefit from ICD implantation, especially for those patients with a poor left ventricular function. In Chapter 2, defibrillation efficacy testing is investigated. The role of a second defibrillation threshold test after implantation appears questionable. With the advances in ICD technology, defibrillation thresholds are low and stable, which changed the mode of death in ICD patients from instantaneous arrhythmic death to heart failure. Our data demonstrate that despite the advanced ICD technology, a subset of patients may require a second defibrillation efficacy test to confirm a poor prognosis. The feasibility of remote monitoring of ICD therapy is discussed in Chapter 3. The expanding indications for ICD therapy and the complexity of current devices have a high impact on follow-up policy. Currently, the quality of medical supervision only depends on scheduled regular follow-up visits, which is time consuming and expensive. Too long follow-up intervals may have the disadvantage of a delay in the awareness of changes of the clinical course of the underlying disease or in the technical status of the device. Transmission of stored ICD data can overcome this problem and thus offers the potential to improve patient care. Finally, a case of Twiddler’s syndrome, which was detected by home monitoring is presented in Chapter 4. Part II Rhythm discrimination by the ICD The primary goal of the ICD is to detect and subsequently terminate ventricular tachyarrhythmias. The secondary goal is to deliver therapy only when necessary. Inappropriate therapy due to atrial tachyarrhythmias is the most common adverse event in ICD patients. In this second part of the thesis, rhythm discrimination by the ICD is investigated. Chapter 5 describes a confusing stored ICD electrogram. This electrogram demonstrates an apparent induction of ventricular tachycardia after appropriate pacing by the ICD. However, accurate analysis demonstrated an artefact representing a ventricular premature beat initiating the ventricular tachycardia. The initial clinical experience with a new dual-chamber algorithm, SMART, is discussed in Chapter 6. This new algorithm is based on comparison of atrial and ventricular rates, which divide tachyarrhythmias into 3 rate branches. Next, applicable single- and dual-chamber arrhythmia discriminators are applied in order to classify the tachyarrhythmia. In our series, the SMART algorithm achieved a sensitivity of 100%, with a positive predictive value of 95.6% for all ventricular arrhythmias. The majority of misclassified episodes appeared to be atrial tachyarrhythmias with stable atrioventricular conduction. In Chapter 7, the evolution of timing-based detection algorithms in ICDs is studied. Over the last 25 years, ICDs base arrhythmia discrimination on timing-based detection criteria in order to avoid inappropriate therapy for atrial tachyarrhythmias. Original single-chamber detection criteria have been implemented as such in dualchamber devices. Atrial signals can be reliably recognized with atrial leads and improved arrhythmia discrimination algorithms based on atrial signals were developed. However, this did not reduce the incidence of inappropriate therapy over time with the development of algorithms as was proven with comparative studies. Chapter 8 evaluated whether clinical characteristics can predict inappropriate therapy due to atrial tachyarrhythmias. We identified a history of atrial tachyarrhythmias and recurrent slow ventricular tachycardias, rate < 170 bpm, as independent predictors of inappropriate therapy. Whether device selection should depend on the knowledge of a history of atrial tachyarrhythmias still is open for debate, as inappropriate therapy equally occurs in patients with single- and dualchamber devices. The results of our prospective, randomized study comparing the performance of tachyarrhythmia detection algorithms in single- and dual-chamber devices are presented in Chapter 9. During a mean follow-up of 12 months, the investigators classified 653 tachyarrhythmia episodes with stored electrograms: 391 episodes were ventricular tachyarrhythmias and 262 epsiodes were atrial tachyarrhythmias. Overall, no significant difference in tachyarrhythmia detection, atrial or ventricular, between single- and dual-chamber devices was observed. Not sinus tachycardia or atrial fibrillation were a problem, but atrial tachyarrhythmias with stable N:1 atrioventricular conduction remain a problem for both devices. In Chapter 10, a systematic approach for the analysis of stored electrograms is proposed. Stored electrograms in ICDs have not only improved our patient management, but also contributed to our understanding of tachyarrhythmias. Stored electrograms are usually visually analyzed, but the analysis can also be performed in a methodological way by application of blocks containing physiologic information. Part III Single-chamber, dual-chamber or biventricular devices In Chapter 11, we studied factors influencing appropriate therapy and survival in ICD patients with single- and dual-chamber devices, in an era that dual chamber devices were only implanted for patients with bradycardia indication. Survival analysis demonstrated no significant difference between patients with single- and dualchamber devices for mortality and for event-free rate of appropriate therapy. A tendency to less inappropriate interventions was observed in a small series of dual chamber devices. In addition, it was observed that a history of atrial fibrillation contributed to appropriate therapy. Resynchronization therapy by means of biventricular pacing is a novel therapy for patients with heart failure and severely diminished left ventricular function associated with intracardiac conduction delay. In Chapter 12, we present a brief review of early trials evaluating the therapeutic effect of biventricular pacing. Furthermore, we propose a method to select the optimal right and left ventricular pacing sites together with a technique of left ventricular lead positioning. The incidence of ventricular tachyarrhythmias in ICD patients with resynchronization therapy is presented in Chapter 13. Event-free survival was analyzed for patients with either a primary or a secondary prevention indication for ICD therapy. Ventricular tachyarrhythmias are very common for congestive heart failure patients with a secondary prevention indication. Patients with primary prophylaxis have an annual event rate of 10%, even when they tend to have a worse heart failure class. The decision-making process to implant an ICD in heart failure patients for primary prophylaxis of sudden cardiac death has presently become a clinical decision, based on low left ventricular ejection fraction plus heart failure.

CRAVT: a prospective, randomized study comparing transvenous cryothermal and radiofrequency ablation in atrioventricular nodal re-entrant tachycardia. (Article)

2004-12-01T00:00:00Z

BACKGROUND: Transvenous catheter ablation of atrioventricular nodal re-entrant tachycardia (AVNRT) with radiofrequency (RF) is effective and safe, but carries a 1-3% incidence of early and potentially late heart block. Cryothermy can create transient effects, and identify potentially successful ablation sites and decrease the risk for permanent heart block. METHODS: In this prospective, randomized trial 102 patients with recurrent narrow QRS-complex tachycardia suggestive of AVNRT were randomized to either RF or cryoablation before a diagnostic study. RESULTS: In 63 patients with AVNRT, 33 were randomized to RF and 30 to cryoablation. Procedural success was achieved, respectively, in 30 (91%) patients in the RF and 28 (93%) in the cryoablation group. The median number of cryothermal applications was significantly lower than the number of RF applications (2 versus 7, p<0.005). No accelerated junctional rhythm was seen with cryothermy, while it was present in 31/33 RF patients. Both fluoroscopy and procedural times were comparable. The radiological position of the successful site in relation to anatomical landmarks was slightly different (p<0.05). No cryothermy related complications were observed, and no permanent AV conduction disturbances occurred. During a mean follow up of 13+/-7 months long-term clinical success was seen in one additional patient in each group. In the same period, 3 patients in both groups experienced recurrent AVNRT. CONCLUSION: Cryoablation is as effective and safe as RF for AVNRT. Significantly fewer applications are necessary, with comparable procedure times. This makes cryothermy useful for the treatment of tachyarrhythmias near the compact AV node.

Ice mapping during cryothermal ablation of accessory pathways in WPW: the role of the temperature time constant. (Article)

2004-03-01T00:00:00Z

AIM: Cryothermal energy has the ability reversibly to demonstrate loss of function with cooling, ice mapping, at less deep temperatures. The purpose of this study was to investigate the time course of the temperature during ice mapping of accessory pathways. METHODS AND RESULTS: Thirteen patients with the Wolff-Parkinson-White (WPW) syndrome underwent cryoablation. After identification of a prospective ablation site, ice mapping was performed by cooling the tip to a minimum of -30 degrees C. Successful ice mapping was defined by loss of accessory pathway (AP) conduction. A total of 104 ice maps were analyzed. Successful ice mapping was demonstrated in 17 attempts. There was no significant difference in mapping temperature between successful and unsuccessful ice mapping (-29.4+/-3.2 degrees Celsius vs -30.4+/-1.7 degrees Celsius). The temperature time constant tau during successful ice mapping was significantly shorter compared with unsuccessful ice mapping (7.0+/-1.1 s vs 10.1+/-1.3 s; P<0.0001). The response time (RT) to mapping temperature of -30 degrees C was significantly prolonged in unsuccessful ice mapping attempts (35.8+/-4.5 s vs 53.5+/-11.0 s; P<0.0001). Significant correlations were found between successful ice mapping and the temperature time constant, and between RT and the temperature time constant (P<0.001). CONCLUSION: The ability to identify prospective ablation sites by ice mapping was demonstrated. Successful ice mapping attempts were characterized by a short temperature time constant and a short response time to mapping temperature with a sudden disappearance of pathway conduction.

Home monitoring in ICD therapy: future perspectives (Article)

2003-01-01T00:00:00Z

The expanding indications for ICD therapy and the complexity of current devices will have impact on follow-up policy. The application of ICD therapy requires elaborate attention to technical aspects, arrhythmias, and the clinical course of the underlying disease. Currently, the quality of medical supervision is dependent on scheduled regular follow-up visits. A disadvantage of long intervals can be a delay in the physician's or patient's awareness of changes in the clinical status. Some patients will need more intensive follow-up while others will have the device as a stand-by and only need technical follow-up. A possibility to address this situation, is the transmission of data, already stored in the implanted device. This will guarantee continuous patient surveillance and could possibly help to avoid unnecessary follow-up visits.

Deterioration of left ventricular function following atrio-ventricular node ablation and right ventricular apical pacing in patients with permanent atrial fibrillation (Article)

2002-01-01T00:00:00Z

AIMS: Transcatheter radiofrequency ablation of the atrio-ventricular (AV) node followed by ventricular pacing has been shown to improve symptoms and quality of life of patients with atrial fibrillation (AF). It is assumed that function improves, but this has been less well demonstrated. The aim of this study was to assess the long-term effect of AV node ablation and ventricular pacing on left ventricular ejection fraction (LVEF) in patients with permanent AF. METHODS AND RESULTS: All 12 patients studied had permanent AF for at least 12 months (mean age 70 years, range 41 to 78). LVEF was determined 6 days and 3 months after AV node ablation by radionuclide ventriculography, at a paced rate of 80 beats . min (-1). Cardiac dimensions were measured by means of transthoracic echocardiography. No major changes in pharmacological therapy were made during 3 months follow-up period. LVEF showed a significant deterioration after 3 months follow-up period for the group (47.5 +/- 14.4%; 6 days after ablation vs 43.2 +/- 13.7%; 3 months after ablation, P < 0.05). There were no significant differences in left ventricular cavity dimensions directly after AV node ablation and 3 months later (LVEDD 51.2 +/- 10.7 mm vs 52.6 +/- 8.6 mm, P = NS: LVESD: 36.1 +/- 14.2 mm vs 36.6 +/- 9.7 mm, P = NS). Left atrial size did not show reduction 3 months after AV node ablation (50.8 +/- 13.6 mm vs 51.0 +/- 14.1 mm, P = NS). CONCLUSION: The restoration of a regular ventricular rhythm following AV node ablation for patients in permanent AF does not result in improvement in left ventricular function.

Initial clinical experience with a new arrhythmia detection algorithm in dual chamber implantable cardioverter defibrillators. (Article)

2001-07-20T00:00:00Z

AIM: Inappropriate therapy, due to poor discrimination of supraventricular tachycardia (SVT) from ventricular tachycardia (VT) remains a major problem in patients with an implantable cardioverter defibrillator (ICD). Theoretically, the addition of atrial sensing in discrimination algorithms should improve this differentiation. The aim of the study is to evaluate the performance of a new tachycardia discrimination algorithm, SMART Detection. METHODS AND RESULTS: Twenty-six patients received a non-thoracotomy ICD system (Phylax AV, Biotronik, Germany). All documented spontaneous arrhythmia episodes were analyzed. During a mean follow-up of 8 months, a total number of 139 events with stored electrograms were recorded in 12 patients. The final diagnosis was ventricular fibrillation (VF) or polymorphic VT (n=20), monomorphic VT (n=69), SVT (n=26), other ventricular arrhythmia (n=3) and T wave oversensing (n=21). In 6 episodes a dual tachycardia was present. Considering SVT episodes, inappropriate therapy occurred in 2 cases of atrial flutter due to stable ventricular rate (<30 ms), 1 case of atrial tachycardia and 2 cases of sinus tachycardia due to a sudden onset (> 10%). CONCLUSION: With the SMART Detection algorithm, discrimination of VT from SVT achieved a sensitivity of 100%, with an accuracy of 95.6% for all ventricular arrhythmias. In the case of SVT, the algorithm appropriately detected and inhibited therapy in 88% of atrial fibrillation.

Transseptal left heart catheterisation guided by intracardiac echocardiography (Article)

2001-01-01T00:00:00Z

OBJECTIVE: To develop a novel approach of transseptal puncture guided by intracardiac echocardiography and to assess its efficacy. METHODS: Transcatheter intracardiac echocardiography with a 9 MHz rotating transducer was performed to guide transseptal puncture in 12 patients (mean age 43.1 years, range 31-68) who underwent radiofrequency catheter ablation of left sided accessory pathways. Initially, the echocardiography and transseptal catheters were placed adjacent to each other in the superior vena cava and were withdrawn to the level of the fossa ovalis. RESULTS: The successful puncture site was associated with visualisation of the fossa ovalis (12 patients, 100%) and the aorta (12 patients, 100%), tenting of the fossa (six patients, 50%), penetration of the needle visualised by the ultrasound catheter (12 patients, 100 %), and echocardiographic contrast material applied in the left atrium (12 patients, 100%). The characteristic jump of the needle onto the fossa ovalis was observed simultaneously with fluoroscopy and intracardiac ultrasound (12 patients, 100%). All procedures were successful. There were no complications associated with the transseptal procedure. CONCLUSIONS: Intracardiac echocardiography is feasible to guide transseptal puncture. The optimal puncture site can be assessed by simultaneous detection of the characteristic downward jump of the transseptal needle onto the fossa ovalis by intracardiac ultrasound and fluoroscopy.