Scholten, M.F.

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.

Acute success and short-term follow-up of catheter ablation of isthmus-dependent atrial flutter; a comparison of 8 mm tip radiofrequency and cryothermy catheters (Article)

2008-04-01T00:00:00Z

Objectives: To compare the acute success and short-term follow-up of ablation of atrial flutter using 8 mm tip radiofrequency (RF) and cryocatheters. Methods: Sixty-two patients with atrial flutter were randomized to RF or cryocatheter (cryo) ablation. Right atrial angiography was performed to assess the isthmus. End point was bidirectional isthmus block on multiple criteria. A pain score was used and the analgesics were recorded. Patients were followed for at least 3 months. Results: The acute success rate for RF was 83% vs 69% for cryo (NS). Procedure times were similar (mean 144±48 min for RF, vs 158±49 min for cryo). More applications were given with RF than with cryo (26±17 vs. 18±10, p<0.05). Fluoroscopy time was longer with RF (29±15 vs. 19±12 min, p<0.02). Peak CK, CK-MB and CK-MB mass were higher, also after 24 h in the cryo group. Troponin T did not differ. Repeated transient block during application (usually with cryoablation) seemed to predict failure. Cryothermy required significantly less analgesia (p<0.01), and no use of long sheaths (p<0.005). The isthmus tended to be longer in the failed procedures (p=0.117). This was similar for both groups, as was the distribution of anatomic variations. Recurrences and complaints in the successful patients were similar for both groups, with a very low recurrence of atrial flutter after initial success. Conclusions: In this randomized study there was no statistical difference but a trend to less favorable outcome with 8 mm tip cryocatheters compared to RF catheters for atrial flutter ablation. Cryoablation was associated with less discomfort, fewer applications, shorter fluoroscopy times and similar procedure times. The recurrence rate was very low. Cryotherapy can be considered for atrial flutter ablation under certain circumstances especially when it has been used previously in the same patient, such as in an AF ablation.

Topics in Atrial Fibrillation Management (Doctoral Thesis)

2006-03-29T00:00:00Z

Atrial fibrillation (AF) is the most frequently encountered arrhythmia in clinical practice. Physicians of almost all specialities have to deal with this arrhythmia and its consequences. The incidence of AF rises proportional with age. 75 % of patients with AF are older than 75 years. AF is not a benign disease. It can result in symptomatic palpitations, symptoms of pump failure, and above all an increase in the incidence of thrombo-embolic events like stroke. In the Framingham study it was shown that AF also independently increases mortality. In patients with heart failure the presence of AF further increases the risk of death. For a long time the only therapy available to the treating physician was digoxin. Today the therapeutic options are too numerous to cover in one thesis, however, they options are mentioned briefly in chapter one.

Imaging of a coronary artery bypass graft during coronary sinus venography (Article)

2006-01-01T00:00:00Z

Retrograde coronary sinus perfusion to maintain viability during cardiac surgery means that a connection via the capillary system to the coronary arteries, and potentially bypass grafts, may be possible. Coronary sinus (CS) venography prior to resynchronisation therapy in this patient with previous bypass grafting was associated with visualisation of these grafts.

Anticoagulation in atrial fibrillation and flutter. (Article)

2005-09-01T00:00:00Z

Atrial fibrillation and atrial flutter are important risk factors for stroke. Based on a literature search, pathogenesis of thromboembolism, risk assessment in patients, efficacy of anticoagulation therapy and its alternatives are discussed. Special emphasis is put on issues like paroxysmal atrial fibrillation, atrial flutter and anticoagulation surrounding catheter ablation and cardioversion. A strategy for anticoagulation around the time of pulmonary vein ablation is suggested.

Ablation lesions in Koch's triangle assessed by three-dimensional myocardial contrast echocardiography. (Article)

2004-12-09T00:00:00Z

BACKGROUND: Myocardial contrast echocardiography (MCE) allows visualization of radiofrequency (RF) ablation lesions in the left ventricle in an animal model. Aim: To test whether MCE allows visualization of RF and cryo ablation lesions in the human right atrium using three-dimensional echocardiography. METHODS: 18 patients underwent catheter ablation of a supraventricular tachycardia and were included in this prospective single-blind study. Twelve patients were ablated inside Koch's triangle and 6, who served as controls, outside this area. Three-dimensional echocardiography of Koch's triangle was performed before and after the ablation procedure in all patients, using respiration and ECG gated pullback of a 9 MHz ICE transducer, with and without continuous intravenous echocontrast infusion (SonoVue, Bracco). Two independent observers analyzed the data off-line. RESULTS: MCE identified ablation lesions as a low contrast area within the normal atrial myocardial tissue. Craters on the endocardial surface were seen in 10 (83%) patients after ablation. Lesions were identified in 11 out of 12 patients (92%). None of the control patients were recognized as having been ablated. The confidence score of the independent echo reviewer tended to be higher when the number of applications increased. CONCLUSIONS: 1. MCE allows direct visualization of ablation lesions in the human atrial myocardium. 2. Both RF and cryo energy lesions can be identified using MCE.

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.

Comparison of monophasic and biphasic shocks for transthoracic cardioversion of atrial fibrillation (Article)

2003-01-01T00:00:00Z

OBJECTIVE: To compare the efficacy of cardioversion in patients with atrial fibrillation between monophasic damped sine waveform and rectilinear biphasic waveform shocks at a high initial energy level and with a conventional paddle position. DESIGN: Prospective randomised study. PATIENTS AND SETTING: 227 patients admitted for cardioversion of atrial fibrillation to a tertiary referral centre. RESULTS: 70% of 109 patients treated with an initial 200 J monophasic shock were cardioverted to sinus rhythm, compared with 80% of 118 patients treated with an initial 120 J biphasic shock (NS). After the second shock (360 J monophasic or 200 J biphasic), 90% of the patients were in sinus rhythm in both groups. The mean cumulative energy used for successful cardioversion was 306 J for monophasic shocks and 159 J for biphasic shocks (p < 0.001). CONCLUSIONS: A protocol using monophasic waveform shocks in a 200-360 J sequence has the same efficacy (90%) as a protocol using rectilinear biphasic waveform shocks in a 120-200 J sequence. This equal efficacy is achieved with a significantly lower mean delivered energy level using the rectilinear biphasic shock waveform. The potential advantage of lower energy delivery for cardioversion of atrial fibrillation needs further study.