Automatic atrial anti-tachy pacing for the termination of spontaneous atrial tachyarrhythmias: clinical experience with a novel dual-chamber pacemaker.
Automatic atrial anti-tachy pacing (aATP) is a novel approach to treat paroxysmal/persistent atrial tachyarrhythmias in pacemaker patients. To evaluate the efficacy of aATP in terminating spontaneous atrial flutter/tachycardia episodes (AT), a dual-chamber stimulator with extensive diagnostic capabilities and programmable aATP therapies (AT500(TM), Medtronic Inc.) was implanted in 30 patients with conventional pacing indications. During a mean follow-up time of 5.5 (1-12) months, aATP was delivered for 10494 AT. According to automatic device analysis, 8289 AT were treated with success (success-rate 79.0%). On 468 AT stored with the corresponding atrial EGM, an additional manual analysis was performed. The success-rate based on automatic analysis of these AT episodes (73.1%) was comparable to that found for all treated AT (79.0%), but manual EGM analysis revealed that only 209 of the 468 treated AT episodes (44.7%) were actually terminated by aATP. The aATP success-rate in the slower (cycle length 360-270 ms) AT detection zone was significantly higher (73.8%, 62/84 eps) than in the overlapping, faster (cycle length 270-220 ms) AT zone (38.3%, 147/384 eps, P<0.01).


CONCLUSIONS
According to manual analysis, 1. aATP was safe and had a success-rate of 44.7%, 2. aATP success-rate was higher for AT in the slower than in the faster detection zone and 3. automatic analysis overestimated the efficacy of aATP.
Vollmann
D
D
Department of Cardiology and Pneumology, Georg-August-University, Goettingen, Germany. DirkVollmann2000@aol.com
Stevens
J
J
Buchwald
A B
AB
Unterberg
C
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation; D004869:Equipment Safety / Q000295:instrumentation; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006325:Heart Atria / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012680:Sensitivity and Specificity; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome