Vourvouri, E.C.

Parameters for coronary plaque vulnerability assessed with multidetector computed tomography and intracoronary ultrasound correlation (Article)

2009-11-01T00:00:00Z

In the absence of a fixed relationship between plaque vulnerability and flow-limiting stenosis, alternative morphological expressions exist that could predict the liability of coronary lesions to rapidly progress or rupture, causing acute coronary syndromes. Modern multidetector computed tomography technology is capable of noninvasively detecting lesion location, attenuation, remodeling and calcification pattern, which may be considered as surrogate morphological markers of vulnerability and could contribute to increase the prognostic value of individual coronary plaque burden.

Quantification of coronary plaque by 64-slice computed tomography: A comparison with quantitative intracoronary ultrasound (Article)

2008-05-01T00:00:00Z

BACKGROUND: Noninvasive assessment of coronary atherosclerotic plaque may be useful for risk stratification and treatment of atherosclerosis. MATERIALS AND METHODS: We studied 47 patients to investigate the accuracy of coronary plaque volume measurement acquired with 64-slice multislice computed tomography (MSCT), using newly developed quantification software, when compared with quantitative intracoronary ultrasound (QCU). Quantitative MSCT coronary angiography (QMSCT-CA) was performed to determine plaque volume for a matched region of interest (regional plaque burden) and in significant plaque defined as a plaque with ≥50% area obstruction in QCU, and compared with QCU. Dataset with image blurring and heavy calcification were excluded from analysis. RESULTS: In 100 comparable regions of interest, regional plaque burden was highly correlated (coefficient r = 0.96; P < 0.001) between QCU and QMSCT-CA, but QMSCT-CA overestimated the plaque burden by a mean difference of 7 ± 33 mm (P = 0.03). In 76 significant plaques detected within the regions of interest, plaque volume determined by QMSCT-CA was highly correlated (r = 0.98; P < 0.001) with a slight underestimation of 2 ± 17 mm (P = not significant) when compared with QCU. Calcified and mixed plaque volume was slightly overestimated by 4 ± 19 mm (P = ns) and noncalcified plaque volume was significantly underestimated by 9 ± 11 mm (P < 0.001) with QMSCT-CA. Overall, the limits of agreement for plaque burden/volume measurement between QCU and QMSCT-CA were relatively large. Reproducibility for the measurements of regional plaque burden with QMSCT-CA was good, with a mean intraobserver and interobserver variability of 0% ± 16% and 4% ± 24%, respectively. CONCLUSIONS: Quantification of coronary plaque within selected proximal or middle coronary segments without image blurring and heavy calcification with 64-slice CT was moderately accurate with respect to intravascular ultrasound and demonstrated good reproducibility. Further improvement in CT resolution is required for more reliable measurement of coronary plaques using quantification software.

Comparison of Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography in Women Versus Men With Angina Pectoris (Article)

2007-11-15T00:00:00Z

We compared the diagnostic accuracy of 64-slice computed tomographic (CT) coronary angiography to detect significant coronary artery disease (CAD) in women and men. The 64-slice CT coronary angiography was performed in 402 symptomatic patients, 123 women and 279 men, with CAD prevalence of 51% and 68%, respectively. Significant CAD, defined as ≥50% coronary stenosis on quantitative coronary angiography, was evaluated on a patient, vessel, and segment level. The sensitivity and negative predictive value to detect significant CAD was very good, both for women and men (100% vs 99%, p = NS; 100% vs 98%, p = NS), whereas diagnostic accuracy (88% vs 96%; p <0.01), specificity (75% vs 90%, p <0.05), and positive predictive value (81% vs 95%, p <0.001) were lower in women. The per-segment analysis demonstrated lower sensitivity in women compared with men (82% vs 93%, p <0.001). The sensitivity in women did not show a difference in proximal and midsegments, but was significantly lower in distal segments (56% vs 85%, p <0.05) and side branches (54% vs 89%, p <0.001). In conclusion, CT coronary angiography reliably rules out the presence of obstructive CAD in both men and women. Specificity and positive predictive value of CT coronary angiography were lower in women. The sensitivity to detect stenosis in small coronary branches was lower in women compared with men.

64-Slice CT coronary angiography in patients with non-ST elevation acute coronary syndrome (Article)

2007-11-01T00:00:00Z

Background: A high diagnostic accuracy of 64-slice CT coronary angiography (CTCA) has been reported in selected patients with stable angina pectoris, but only scant information is available in patients with non-ST elevation acute coronary syndrome (ACS). Objectives: To study the diagnostic performance of 64-slice CTCA in patients with non-ST elevation ACS. Patients and methods: 64-slice CTCA was performed in 104 patients (mean (SD) age 59 (9) years) with non-ST elevation ACS. Two independent, blinded observers assessed all coronary arteries for stenosis, using conventional quantitative angiography as a reference. Coronary lesions with ≥50% luminal narrowing were classified as significant. Results: Conventional coronary angiography demonstrated the absence of significant disease in 15% (16/104) of patients, and the presence of single-vessel disease in 40% (42/104) and multivessel disease in 44% (46/104) of patients. Sensitivity for detecting significant coronary stenoses on a patient-by-patient analysis was 100% (88/88; 95% CI 95 to 100), specificity 75% (12/16; 95% CI 47 to 92), and positive and negative predictive values were 96% (88/92; 95% CI 89 to 99) and 100% (12/12; 95% CI 70 to 100), respectively. Conclusion: 64-slice CTCA has a high sensitivity to detect significant coronary stenoses, and is reliable to exclude the presence of significant coronary artery disease in patients who present with a non-ST elevation ACS.

Spiral multislice computed tomography coronary angiography: A current status report (Article)

2007-09-01T00:00:00Z

Multislice computed tomography coronary angiography (MSCT-CA) has emerged as a powerful noninvasive diagnostic modality to visualize the coronary arteries and to detect significant coronary stenoses. The latest generation 64-slice computed tomography (CT) scanners is a robust technique which allows high-resolution, isotropic, nearly motion-free coronary imaging. Coronary stenoses are detected with high sensitivity and a normal scan accurately rules out the presence of a coronary stenosis. With the introduction of further novel concepts in CT-technology one may expect that MSCT-CA will become a clinically used diagnostic tool.

Prognostic Significance of Myocardial Ischemia During Dobutamine Stress Echocardiography in Asymptomatic Patients With Diabetes Mellitus and No Prior History of Coronary Events (Article)

2007-05-01T00:00:00Z

The prognostic significance of myocardial ischemia assessed by dobutamine stress echocardiography in asymptomatic patients with diabetes mellitus who have no previous coronary artery disease remains unclear. We assessed the value of dobutamine stress echocardiography for risk stratification in 161 asymptomatic patients with type 2 diabetes (mean 62 ± 12 years of age; 96 men) who had no previous myocardial infarction or revascularization. End point during follow-up was hard cardiac events (cardiac death and nonfatal myocardial infarction). Ischemia was detected in 45 patients (28%). During a median follow-up of 5 years, 40 patients (25%) died (18 cardiac deaths) and 7 patients had nonfatal myocardial infarction (25 hard cardiac events). An abnormal dobutamine stress echocardiogram was associated with a higher mortality compared with a normal dobutamine stress echocardiogram (p = 0.03). In an incremental multivariate analysis model, clinical predictors of hard cardiac events were age and hypercholesterolemia. Ischemia was incremental to the clinical parameters. In conclusion, myocardial ischemia is an independent predictor of cardiac events in asymptomatic diabetic patients with no previous coronary artery disease.

Prognostic Significance of Akinesis Becoming Dyskinesis During Dobutamine Stress Echocardiography (Article)

2007-03-01T00:00:00Z

Background: Akinesis becoming dyskinesis (AKBD) at high-dose dobutamine stress echocardiography (DSE) has been disregarded as a marker of myocardial ischemia. However, its prognostic significance is unknown. Objectives: We sought to assess the long-term outcome of patients with AKBD during DSE. Methods: A total of 731 patients (age 62 ± 15 years, 628 men) with two or more akinetic left ventricular segments at rest underwent DSE and were followed up for a mean period of 5 ± 2.7 years. The end points considered during follow-up were hard cardiac events (cardiac death and nonfatal myocardial infarction) and heart failure. Results: Dyskinesis in two or more segments at peak stress developed in 60 patients (8%). Resting wall-motion score index was 2.6 ± 0.56 in patients with AKBD versus 2.3 ± 0.55 in patients without AKBD (P = .0002). Ischemia occurred in 197 patients (27%). During follow-up, 254 patients (35%) developed hard cardiac events and 204 patients (28%) developed heart failure. In all, 226 patients (31%) died of various causes (cardiac death in 172 patients). The annualized hard cardiac event rate was 11% in patients with AKBD and 6% in patients without (P = .03). The incidence of heart failure was significantly higher in patients with AKBD than without (47% vs 26%, P < .001). Independent predictors of hard cardiac events were age (hazard ratio [HR] 1.03 [confidence interval {CI} = 1.01-1.04]), previous myocardial infarction (HR 1.4 [CI = 1.1-1.9]), diabetes mellitus (HR 1.8 [CI = 1.3-2.5]), resting wall-motion score index (HR 1.11 [CI = 1.01-1.04]), and AKBD (HR 1.6 [CI = 1.1-2.4]). Conclusion: AKBD at peak DSE is associated with increased risk of cardiac events in patients with akinetic segments at baseline echocardiogram.

Evaluation of a hand carried cardiac ultrasound device in an outpatient cardiology clinic (Article)

2005-01-01T00:00:00Z

OBJECTIVE: To determine the diagnostic potential of a hand carried cardiac ultrasound (HCU) device (OptiGo, Philips Medical Systems) in a cardiology outpatient clinic and to compare the HCU diagnosis with the clinical diagnosis and diagnosis with a full featured standard echocardiography (SE) system. METHODS: 300 consecutive patients took part in the study. The HCU examination was performed by an experienced echocardiographer before patients visited the cardiologist. The echocardiographer noted whether the HCU device was able to confirm or reject the referral diagnosis, which abnormality was detected, and whether SE investigation was necessary. Physical examination by a cardiologist followed and thereafter, whenever required, a complete study with an SE was carried out. The HCU data were compared with the clinical diagnosis of the cardiologist and the SE diagnosis in a blinded manner. RESULTS: The cardiologist referred 203 of 300 patients for an SE study and 13 patients for transoesophageal echocardiography. In 84 patients no further examination was considered necessary. HCU echocardiography was able to confirm or reject the suspected clinical diagnosis in 159 of 203 (78%) patients. In 44 of 203 (22%) patients SE Doppler was needed. Agreement between the HCU device and the SE system for the detection of major abnormalities was excellent (98%). The HCU device missed 4% of the major findings. Among the 84 patients not referred for an SE, the HCU device detected unsuspected major abnormalities missed with the physical examination in 14 (17%). CONCLUSION: Integration of an HCU device with the physical examination augments the yield of information.

Long term outcome in patients with silent versus symptomatic ischaemia during dobutamine stress echocardiography (Article)

2005-01-01T00:00:00Z

OBJECTIVES: To compare the long term prognosis of patients having silent versus symptomatic ischaemia during dobutamine stress echocardiography (DSE). DESIGN: Observational study. SETTING: Tertiary referral centre. PATIENTS: 931 patients who experienced stress induced myocardial ischaemia during DSE. RESULTS: Silent ischaemia was present in 643 of 931 patients (69%). The number of dysfunctional segments at rest (mean (SD) 9.6 (5.1) v 8.8 (5.0), p = 0.1) and of ischaemic segments (3.5 (2.2) v 3.8 (2.1), p = 0.2) was comparable in both groups. During a mean (SD) follow up of 5.5 (3.3) years, there were 169 (18%) cardiac deaths and 86 (9%) non-fatal infarctions. Multivariable Cox regression analysis showed age (hazard ratio (HR) 1.1, 95% confidence interval (CI) 1.02 to 1.05), previous myocardial infarction (HR 1.4, 95% CI 1.1 to 2.0), and number of ischaemic segments during the test (HR 2.0, 95% CI 1.0 to 3.7) as independent predictors of cardiac death and myocardial infarction. For every additional ischaemic segment there was a twofold increment in risk of late cardiac events. The annual cardiac death or myocardial infarction rate was 3.0% in patients with symptomatic ischaemia and 4.6% in patients with silent ischaemia (p < 0.01). Silent induced ischaemia was an independent predictor of cardiac death and myocardial infarction (HR 1.7, 95% CI 1.1 to 2.0). During follow up symptomatic patients were treated more often with cardioprotective therapy (p < 0.01) and coronary revascularisation (145 of 288 (50%) v 174 of 643 (27%), p < 0.001). CONCLUSIONS: Patients with silent ischaemia had a similar extent of myocardial ischaemia during DSE compared to patients with symptomatic ischaemia but received less cardioprotective treatment and coronary revascularisation and experienced a higher cardiac event rate.

Improvement of stress LVEF rather than rest LVEF after coronary revascularisation in patients with ischaemic cardiomyopathy and viable myocardium (Article)

2005-01-01T00:00:00Z

OBJECTIVE: To evaluate prospectively the response of left ventricular ejection fraction (LVEF) to high dose dobutamine infusion in patients showing substantial viability, with and without improved resting LVEF after revascularisation. METHODS: Before and 9-12 months after revascularisation, 50 patients with ischaemic cardiomyopathy (LVEF 32 (8)%) and substantial myocardial viability (> or = 4 viable segments) underwent radionuclide ventriculography and dobutamine stress echocardiography. Patients were divided into group 1, patients with, and group 2, patients without significant improvement in resting LVEF (> or = 5% by radionuclide ventriculography) after revascularisation. The response of LVEF during dobutamine stress echocardiography was compared in these two groups. RESULTS: Groups 1 and 2 were comparable in baseline characteristics, resting LVEF, and number of viable segments (mean (SD) 7 (4) v 6 (2), not significant). After revascularisation, the LVEF response during dobutamine stress echocardiography improved significantly in both groups (group 1, 34 (10)% to 56 (8)%; group 2, 32 (10)% to 46 (11)%; both p < 0.001). Interestingly, although resting LVEF did not improve in group 2, peak stress LVEF after revascularisation did (p < 0.001). Group 1 patients had, however, a greater increase in peak stress LVEF (group 1, 22 (10)%; group 2, 13 (9)%; p < 0.01). New York Heart Association and Canadian Cardiovascular Society classes decreased in both groups. CONCLUSIONS: Although patients with viable myocardium did not always have improved rest LVEF after revascularisation, peak stress LVEF improved. Assessment of improvement of resting function may not be the ideal end point to evaluate successful revascularisation.

Pulsed wave tissue Doppler imaging for the quantification of contractile reserve in stunned, hibernating, and scarred myocardium (Article)

2004-01-01T00:00:00Z

OBJECTIVES: To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium. DESIGN: Observational study. SETTING: Tertiary referral centre. PATIENTS: 70 patients with reduced left ventricular function caused by chronic coronary artery disease. METHODS: Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred. RESULTS: 253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001). CONCLUSIONS: Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damage

Relation between left ventricular contractile reserve during low dose dobutamine echocardiography and plasma concentrations of natriuretic peptides (Article)

2004-01-01T00:00:00Z

BACKGROUND: In ischaemic cardiomyopathy, raised plasma concentrations of natriuretic peptides are associated with a poor long term prognosis, while the presence of contractile reserve is a favourable sign. OBJECTIVE: To assess the relation between plasma natriuretic peptides and contractile reserve. DESIGN: Prospective observational study. SETTING: Tertiary referral centre. PATIENTS: 66 consecutive patients undergoing low dose dobutamine stress echocardiography to evaluate contractile reserve in regions with contractile dysfunction at rest, divided into two groups: group 1, 31 patients with ischaemic cardiomyopathy (left ventricular ejection fraction < or = 40%) and heart failure symptoms; group 2, 35 patients with normal left ventricular function. MAIN OUTCOME MEASURES: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), measured using immunoradiometric assays. Contractile reserve was defined as an improvement in segmental wall motion score during infusion of low dose dobutamine. RESULTS: Plasma ANP and BNP concentrations were higher in group 1 than in group 2 (mean (SD): ANP, 17.8 (32.8) v 7.2 (9.7), p < 0.005; BNP, 24.4 (69.0) v 5.0 (14.3) pmol/l, respectively; p < 0.001). In group 1, the presence of contractile reserve was inversely related to ANP and BNP levels; however, patients with contractile reserve had lower ANP and BNP concentrations than patients without contractile reserve (ANP, 14.2 (9.1) v 24.2 (44.2), p < 0.05; BNP, 20.2 (25.5) v 37.5 (93.8) pmol/l, respectively; p < 0.05). CONCLUSIONS: Plasma natriuretic peptide concentrations are raised in patients with left ventricular dysfunction, but in the presence of preserved myocardial contractile reserve, relatively low levels of ANP and BNP are present.

Prognostic value of dobutamine stress echocardiography in patients with diabetes (Article)

2003-01-01T00:00:00Z

OBJECTIVE: The aim of this study was to assess the incremental value of dobutamine stress echocardiography (DSE) for the risk stratification of diabetic patients who are unable to perform an adequate exercise stress test. Exercise capacity is frequently impaired in patients with diabetes. The role of pharmacologic stress echocardiography in the risk stratification of diabetic patients has not been well defined. RESEARCH DESIGN AND METHODS: We studied 396 diabetic patients (mean age 61 +/- 11 years, 252 men [64%]) with limited exercise capacity who underwent DSE for evaluation of known or suspected coronary artery disease (CAD). End points were hard cardiac events (cardiac death and nonfatal myocardial infarction) and all causes of mortality. RESULTS: During a median follow-up of 3 years, 97 patients (24%) died (55 cardiac deaths), and 27 patients had nonfatal myocardial infarction. In an incremental multivariate analysis model, clinical predictors of hard cardiac events were history of congestive heart failure, previous myocardial infarction, hypercholesterolemia, and ejection fraction at rest. The percentage of ischemic segments was incremental to the clinical model in the prediction of hard cardiac events (chi(2) = 37 vs. 18, P < 0.05). Clinical predictors of all causes of mortality were history of congestive heart failure, age, hypercholesterolemia, and ejection fraction at rest. Wall motion score index at peak stress was incremental to the clinical model in the prediction of mortality (chi(2) = 52 vs. 43, P < 0.05). CONCLUSIONS: DSE provides incremental data for the prediction of mortality and hard cardiac events in patients with diabetes who are unable to perform an adequate exercise stress test.

Quantification of regional left ventricular function in Q wave and non-Q wave dysfunctional regions by tissue Doppler imaging in patients with ischaemic cardiomyopathy (Article)

2003-01-01T00:00:00Z

OBJECTIVE: To quantify regional left ventricular (LV) function and contractile reserve in Q wave and non-Q wave regions in patients with previous myocardial infarction. DESIGN: An observational study. SETTING: Tertiary care centre. PATIENTS: 81 patients with previous myocardial infarction and depressed LV function. INTERVENTIONS: All patients underwent surface ECG at rest and pulsed wave tissue Doppler imaging at rest and during low dose dobutamine infusion. The left ventricle was divided into four major regions (anterior, inferoposterior, septal, and lateral). Severely hypokinetic, akinetic, and dyskinetic regions on two dimensional echocardiography at rest were considered dysfunctional. MAIN OUTCOME MEASURES: Regional myocardial systolic velocity (Vs) at rest and the change in Vs during low dose dobutamine infusion (DeltaVs) in dysfunctional regions with and without Q waves on surface ECG. RESULTS: 220 (69%) regions were dysfunctional; 60 of these regions corresponded to Q waves and 160 were not related to Q waves. Vs and DeltaVs were lower in dysfunctional than in non-dysfunctional regions (mean (SD) Vs 6.2 (1.9) cm/s v 7.1 (1.7) cm/s (p < 0.001), and DeltaVs 1.9 (1.9) cm/s v 2.6 (2.5) cm/s (p = 0.009), respectively). There were no significant differences in Vs and DeltaVs among dysfunctional regions with and without Q waves (Q wave regions: Vs 6.2 (1.8) cm/s, DeltaVs 1.6 (2.2) cm/s; non-Q wave regions: Vs 6.3 (1.9) cm/s, DeltaVs 2.0 (2.0) cm/s). CONCLUSIONS: Quantitative pulsed wave tissue Doppler demonstrated that, among dysfunctional regions, Q waves on the ECG do not indicate more severe dysfunction, and myocardial contractile reserve is comparable in Q wave and non-Q wave dysfunctional myocardium.

Clinical utility and cost effectiveness of a personal ultrasound imager for cardiac evaluation during consultation rounds in patients with suspected cardiac disease (Article)

2003-01-01T00:00:00Z

OBJECTIVE: To assess the clinical utility and cost effectiveness of a personal ultrasound imager (PUI) during consultation rounds for cardiac evaluation of patients with suspected cardiac disease. METHODS: 107 unselected patients from non-cardiac departments (55% men) were enrolled in the study. After the physical examination the consultant cardiologist performed an echocardiographic study with a PUI. The final report was given instantly to the referring physician. All patients subsequently underwent a study with a standard echocardiographic device (SED). For each patient the consultant cardiologist noted whether the findings of the PUI were adequate for final diagnosis. The total cost when full echocardiography was used was compared with the cost when the PUI was used. The time interval from request to diagnosis was also compared. RESULTS: In 84 (78.5%) patients no further examination with an SED was regarded as necessary. Twenty three patients (21.5%) required a further detailed examination with the SED because of the need for haemodynamic information. There was an excellent agreement for the detection of abnormalities between the two devices (96%). The total cost was euro;132 per patient with the SED and euro;75 per patient with the PUI. According to this study, the use of the PUI can lead to a 33.4% reduction of total cost. The mean time from request to diagnosis at the authors' institution was four days for the SED and instantly for the PUI, for additional potential cost savings. CONCLUSIONS: Immediate echocardiographic assessment during consultation rounds can lead to significant cost savings and can shorten the time to diagnosis.

Ultrasound stethoscopy (Doctoral Thesis)

2002-11-27T00:00:00Z

In this thesis we repmi the many evaluation studies with the hand-held ultrasound device in the assessment of different cardiac pathologies and in different clinical settings. The reason for using the tetm "ultrasound stethoscopy" is that these devices are augmenting our physical examination by allowing to visualise the heart and hence extend our physical sense of "seeing". Since stethoscopy stands for "seeing the heart" as previously mentioned, the tenn ultrasound stethoscope seems to be the most appropriate term describing these instruments. One could argue that the introduction of echocardiography at the bedside could weaken the importance of auscultation and the physical examination in particular. However, it was echocardiography that brought out the limitations of physical examination in many cardiac conditions and also exposed human auditory limitations (7-10). Although auscultation entered a modem era with the introduction of electronic stethoscopes (11 ), physicians rely on more sophisticated technology. Inadequate training and time pressure due to increasing work load of patients in combination with the availability of advanced technologies are the reasons of poor auscultatory proficiency seen in recently trained physicians particularly in developed countries (12). Nevertheless, we have to admit that direct observation such as seeing is more accurate for cardiac diagnosis than indirect observation such as hearing. "Seeing" enables the preclinical detection of pathologies and especially pathologies that are beyond physical signs, e.g. small mass lesions. The first reactions from experienced echocardiographers to the ultrasound stethoscope were related to its capabilities/limitations and the training required for physicians who use it (13). The last 2 years refinements in the technology of the ultrasound stethoscopes and addition of modalities like spectral Doppler and M-Mode have improved the diagnostic potentials of these devices. No doubt that training is required to use an imaging device. Recently the American Society of Cardiology (14) published guidelines regarding the use of ultrasound stethoscopes recommending Level I of training (15) as an absolute minimal level required. However, recent studies have shown that it is possible to train physicians and students for the detection of significant pathologies in a short period ( 16,17).

Prognostic value of dobutamine-atropine stress myocardial perfusion imaging in patients with diabetes (Article)

2002-01-01T00:00:00Z

OBJECTIVE: Exercise tolerance in patients with diabetes is frequently impaired due to noncardiac disease such as claudication and polyneuropathy. This study assesses the prognostic value of dobutamine stress myocardial perfusion imaging in patients with diabetes. RESEARCH DESIGN AND METHODS: A total of 207 consecutive diabetic patients who were unable to undergo exercise stress testing underwent dobutamine-atropine stress myocardial perfusion imaging. Follow-up was successful in 206 of 207 (99.5%) patients. A total of 12 patients underwent early (<60 days) revascularization and were excluded from the analysis. End points during follow-up were hard cardiac events, defined as cardiac death and nonfatal myocardial infarction. RESULTS: Abnormal myocardial perfusion was detected in 125 (64%) patients. During 4.1 +/- 2.4 years of follow-up, 73 (38%) deaths occurred, 36 (49%) of which were due to cardiac causes. Nonfatal myocardial infarction occurred in 7 (4%) patients, and 45 (23%) patients underwent late coronary revascularization. Cardiac death occurred in 2 of 69 (3%) patients with normal myocardial perfusion and in 34 of 125 (27%) patients with perfusion abnormalities (P < 0.0001). A multivariable Cox proportional hazard model demonstrated that, in addition to clinical and stress test data, an abnormal scan had an incremental prognostic value for prediction of cardiac death (hazard ratio 7.2, 95% CI 1.7-30). The summed stress score was an important predictor of cardiac death; the hazard ratio was 1.2 (95% CI 1.07-1.34) per one-unit increment. CONCLUSIONS: Dobutamine-atropine stress myocardial perfusion imaging provides additional prognostic information incremental to clinical data in patients with diabetes who are unable to undergo exercise stress testing.

Left ventricular hypertrophy screening using a hand-held ultrasound device (Article)

2002-01-01T00:00:00Z

AIMS: To test the diagnostic potential of a hand-held ultrasound device for screening for left ventricular hypertrophy in a hypertensive population using a standard echocardiographic system as a reference. METHODS: One hundred consecutive hypertensive patients were enrolled. An experienced investigator performed measurements of the thickness of the anterior septum and posterior wall using the parasternal 2D-long axis view and the end-diastolic dimension of the left ventricle with both imaging devices. Left ventricular hypertrophy was defined as an increase in left ventricular mass > or = 134 g x m(-2) for men and > or = 110 g x m(-2) for women, when indexed for body surface area and > or = 143 g x m(-1) for men and > or = 102 g x m(-1) for women, when indexed for height. RESULTS: Sixty-five men and 35 women were studied (age 60 +/- 11 years); mean duration of hypertension: 13 +/- 11 years; mean blood pressures: systolic 150 +/- 20 mmHg and diastolic 89 +/- 11 mmHg. The anterior septum and posterior wall were visualized in all patients with both imaging devices. The standard echocardiographic system identified left ventricular hypertrophy by body surface area in 18 (18%) patients and by height in 26 (26%) patients. The agreement between the standard echocardiographic system and the hand-held device for the assessment of left ventricular hypertrophy was 93%, kappa: 0.77 (left ventricular mass/body surface area) and 90%, kappa: 0.76 (left ventricular mass/height). CONCLUSIONS: We conclude that hand-held devices can be effectively applied for screening for left ventricular hypertrophy in hypertensive patients.

Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography (Article)

2001-01-01T00:00:00Z

OBJECTIVE: To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. PATIENTS: 30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men). METHODS: Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with (99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch. RESULTS: Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, kappa = 0.77, p = 0.001 v fundamental imaging). CONCLUSIONS: Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability.

Aneurysm of the abdominal aorta (Article)

2001-01-01T00:00:00Z