Comparison of immediate and delayed automatic antitachycardia pacing for the termination of atrial tachyarrhythmias.
OBJECTIVE
Automatic atrial antitachycardia pacing (ATP) can terminate atrial tachyarrhythmias (ATs) in patients with an implanted device. We investigated if the programmable delay between AT onset and ATP influences therapy efficacy.


METHODS
Patients with intermittent ATs and an implanted DDDRP pacemaker were randomized to receive ATP either immediately or 30min after AT detection. After four months stored data were interrogated, AT-related symptoms were assessed, and patients crossed over to the alternative treatment arm for another four months. Stored atrial electrograms were analyzed for degree of AT organization and ATP success.


RESULTS
In 22 patients (64% male; 72+/-7 years), ATP success rates were higher during immediate than during delayed ATP (device classification: 59+/-7% vs. 22+/-5%, P<0.01; manual analysis: 36+/-6% vs. 12+/-5%, P<0.01). Higher efficacy of immediate ATP was associated with a larger proportion of organized (Type I) AT prior to therapy (71% vs. 44% during delayed ATP). No difference was found in total AT numbers and duration, AT burden or related symptoms.


CONCLUSIONS
The programmable delay between arrhythmia onset and therapy delivery significantly influences the success-rate of ATP. However, a higher efficacy of immediate compared with delayed ATP does not translate into a reduction of AT burden or related symptoms.
Vollmann
Dirk
D
Department of Cardiology and Pneumology, Georg-August-University, Göttingen, Germany. dirkvollmann2000@aol.com
Kollet
Eveline
E
Lüthje
Lars
L
Busse
Sabine
S
Unterberg
Christina
C
D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013610:Tachycardia / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome