Comparison of two antitachycardia pacing modes in supraventricular tachycardia.

The comparative efficacy of two different antitachycardia pacing techniques was evaluated in 22 consecutive patients who received the pacemaker Intertach with an atrial electrode for drug refractory, recurrent supraventricular tachycardia (SVT). The Intertach has two consecutive programmable primary and secondary termination modes. The termination programs investigated were adaptive autodecremental burst pacing and adaptive decremental scanning. Atrioventricular nodal reentrant tachycardia was present in 15 patients and atrioventricular reentrant tachycardia due to Wolff-Parkinson-White syndrome in seven patients. The prospective comparison was arranged in a randomized, cross-over study over a period of 12 months. To assess long-term efficacy, diagnostic data of the pacemakers were obtained in intervals of 3 months. In addition, noninvasive programmed stimulation was performed to compare the incidence of pacing-induced atrial fibrillation with both termination programs. During a follow-up of 12 months the overall success rate of autodecremental burst pacing and decremental scanning was 80% and 95%, respectively. Decremental scanning was more effective in 12 patients and less successful in two patients than autodecremental burst pacing. During noninvasive electrophysiological studies, pacing induced atrial fibrillation could be documented in three of ten patients (30%) using autodecremental burst pacing, compared to one of ten patients (10%) using decremental scanning. These data suggest that decremental scanning proved to be more successful in the long-term management of patients with recurrent SVT than autodecremental burst pacing. Furthermore, the occurrence of pacing-induced atrial fibrillation could be documented more frequently with autodecremental burst pacing compared to decremental scanning.