Israel Medical Association Journal

Background: Patients with right bundle branch block (RBBB) prior to transcatheter aortic valve implantation (TAVI) are at high risk for immediate post-procedural heart block and long-term mortality when discharged without a pacemaker.

Objectives: To test whether prophylactic permanent pacemaker implantation (PPI) is beneficial.

Methods: Of 795 consecutive patients who underwent TAVI, 90 patients had baseline RBBB. We compared characteristics and outcomes of the prophylactic PPI with post-TAVI PPI. Need for pacing was defined as  greater than 1% ventricular pacing.

Results: Forty patients with RBBB received a prophylactic PPI (group 1), and in 50 the decision was based on standard post-procedural indications (group 2). There were no significant differences in clinical baseline characteristics. One patient developed a tamponade after a PPI post-TAVI. A trend toward shorter hospitalization duration in group 1 patients was observed (P = 0.06). On long-term follow-up of 848 ± 56 days, no differences were found in overall survival (P = 0.77), the composite event-free survival of both mortality and hospitalizations (P = 0.66), or mortality and syncope (P = 0.65). On multivariate analysis, independent predictors of the need for pacing included baseline PR interval increase of 10ms (odds ratio [OR] 1.21 per 10 ms increment 95% confidence interval [95%CI] 1.02–1.44, P = 0.028), and the use of new generation valves (OR 3.92, 95%CI 1.23–12.46, P = 0.023).

Conclusions: In patients with baseline pre-TAVI RBBB, no outcome differences were found with prophylactic PPI. On multivariate analysis, predictors of the need for pacing included baseline long PR interval, and the use of newer generation valves.

Background: Idiopathic left ventricular tachycardia with a right bundle branch block configuration and left axis deviation, first described by Belhassen et al., is a rare electrocardiographic-electrophysiologic entity. Radiofrequency catheter ablation has been proposed as a good therapeutic option, but the best criteria for determining the optimal site of ablation are still under debate.

Objectives: To report the clinical features, electrophysiologic characteristics, results of RFA[1], and long-term outcome in 18 patients with "Belhassen's VT” treated in our laboratory during the last 10 years, stressing the best electrophysiologic criteria for determining the optimal site of ablation.

Methods: Eighteen consecutive patients with this specific VT[2] underwent RFA in our laboratory during the last 10 years. RFA was acutely successful in 17 patients after one or two procedures (15 and 2 patients, respectively) using 4.1 ± 2.2 RF pulses. The putative ablation sites were defined by good pace-mapping (3 patients), earliest recorded Purkinje spike prior to the QRS onset during VT or sinus rhythm (6 patients), earliest endocardial activation during VT (1 patient), and diastolic potential preceding the Purkinje spike during VT and/or late diastolic potential in sinus rhythm (7 patients). In the patients with a definite successful ablation, the ratio of successful to unsuccessful radiofrequency pulse delivery to the diastolic potential site was compared to that of other methods. The ratio of successful RFA at the diastolic potential site (5:8) was higher than in the other methods (8:31), and the difference was statistically significant (P = 0.05). Successful ablation sites were more basal when the diastolic potential site was chosen.

Conclusion: The results of the present study confirm the high success rate and safety of RFA using conventional techniques in the management of “Belhassen VT,” suggesting that this procedure can be proposed as a first-line therapy. Ablating at a site demonstrating a late diastolic potential is at least as effective as ablating at a ventricular exit site, although the use of combined electrophysiologic criteria may be the optimal approach.