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.

Serial postoperative follow-up studies demonstrate incomplete recovery of contractile function at 3 months. The diagnostic accuracy of dobutamine echocardiography for predicting recovery is dependent on three factors: the combining of low and high dobutamine dosages, the severity of regional dyssynergy and the timing of evaluation.

KIMMAN, G.P., ET AL.: Ten Year Follow-Up After Radiofrequency Catheter Ablation for AtrioventricularNodal Reentrant Tachycardia in the Early Days. Background: Radiofrequency (RF) catheter ablation is highly effective with a low complication rate. However, lesions created by RF energy are irreversible, inhomogeneous, and therefore potentially proarrhythmic.Objectives: The aim of this study was to examine the magnitude and importance of long-term proarrhythmic effects of RF energy.Methods and Results: Between 1991 and 1995, 120 patients underwent RF ablation for atrioventricular nodal reentrant tachycardia (AVNRT). Patient data were collected by contacting patients and/or filling out a questionnaire, and medical files were screened for recurrent, documented arrhythmias, pharmacological treatment, and repeated EP study. Referring cardiologists were asked about recurrences of tachyarrhythmias. Fourteen patients (11%) were lost to follow-up. During a mean follow-up of 10 years, six patients died. Recurrences of AVNRT were not any more observed after 3 years after ablation. A total of 29 patients (24%) suffered from new arrhythmias, 6 from type 1 atrial flutter, 6 from atrial tachycardia, 9 from atrial fibrillation, and finally 16 from symptomatic premature atrial contractions (PACs), needing medical treatment or a combination of these arrhythmias. Nine patients underwent pacemaker implantation, 4 after developing procedural atrioventricular (AV) conduction disturbances, 2 after His ablation for permanent atrial fibrillation, 1 patient for sick sinus syndrome, and another 2 patients after developing late AV block, respectively, 7 and 9 years after ablation.Conclusion: During long-term follow-up after RF ablation for AVNRT, no AVNRT recurrences were observed, but 29 patients (24%) suffered from new arrhythmias or late AV block. This potential proarrhythmic effect of RF energy promotes the application of alternative energy sources for ablative therapies for cardiac arrhythmias. (PACE 2005; 28:1302-1309 atrioventricular nodal reentrant tachycardia, radiofrequency, catheter ablation, proarrhythmia, long-term follow-up

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Several diagnostic imaging techniques are available for assessment of the anatomical and functional characteristics of CAFs.

Aims Although arrhythmia surgery and radiofrequency catheter ablation to cure atrioventricular nodal reentrant tachycardia differ in technical concept, the late results of both methods, in terms of elimination of the arrhythmogenic substrate and procedure-related new and different arrhythmias, have never been compared. This constituted the purpose of this prospective follow-up study. Methods and ResultsBetween 1988 and 1992, 26 patients were surgically treated using perinodal dissection or 'skeletonization', and from 1991 up to 1995, 120 patients underwent radiofrequency modification of the atrioventricular node for atrioventricular nodal reentrant tachycardia. The acute success rates of surgery and radiofrequency catheter ablation were 96% and 92%, respectively. Late recurrence rate in the surgical and radiofrequency catheter ablation groups was 12% and 17%, respectively. Mean follow-up was 53 months in the surgical group and 28 months in the radiofrequency catheter ablation group. The final success rate after repeat intervention was 100% in the surgical group and 98% in the radiofrequency catheter ablation group. Comparison of the initial and recent series of radiofrequency catheter ablated patients showed an increased initial success rate with fewer applications. In the radiofrequency catheter ablation group, a second-or third-degree block developed in three patients (2%), requiring permanent pacing, whereas in the surgical group no complete atrioventricular block was observed. Inappropriate sinus tachycardia needing drug treatment was observed in 13 patients (11%), mostly after fast pathway ablation, but was never observed after surgery. New and different supraventricular tachyarrhythmias arose in 27% of the patients in the surgical group and in 11% of the radiofrequency catheter ablation group, but did not clearly differ. ConclusionThis one-institutional follow-up study demonstrated comparable initial and late success rates as well as incidence of new and different supraventricular arrhythmias following arrhythmia surgery and radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia. Today radiofrequency catheter ablation has replaced arrhythmia surgery for various reasons, but the late arrhythmic side-effects warrant refinement of technique. (Eur Heart J 1999; 20: 527-534)

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.

Background One third of primary prevention implantable cardioverter‐defibrillator patients receive appropriate therapy, but all remain at risk of defibrillator complications. Information on these complications in contemporary cohorts is limited. This study assessed complications and their risk factors after defibrillator implantation in a Dutch nationwide prospective registry cohort and forecasts the potential reduction in complications under distinct scenarios of updated indication criteria. Methods and Results Complications in a prospective multicenter registry cohort of 1442 primary implantable cardioverter‐defibrillator implant patients were classified as major or minor. The potential for reducing complications was derived from a newly developed prediction model of appropriate therapy to identify patients with a low probability of benefitting from the implantable cardioverter‐defibrillator. During a follow‐up of 2.2 years (interquartile range, 2.0–2.6 years), 228 complications occurred in 195 patients (13.6%), with 113 patients (7.8%) experiencing at least one major complication. Most common ones were lead related (n=93) and infection (n=18). Minor complications occurred in 6.8% of patients, with lead‐related (n=47) and pocket‐related (n=40) complications as the most prevailing ones. A surgical reintervention or additional hospitalization was required in 53% or 61% of complications, respectively. Complications were strongly associated with device type. Application of stricter implant indication results in a comparable proportional reduction of (major) complications. Conclusions One in 13 patients experiences at least one major implantable cardioverter‐defibrillator–related complication, and many patients undergo a surgical reintervention. Complications are related to defibrillator implantations, and these should be discussed with the patient. Stricter implant indication criteria and careful selection of device type implanted may have significant clinical and financial benefits.