DDD versus DDDR pacing: effects on the occurrence of atrial arrhythmias and the quality of life in patients with the sick sinus syndrome.

OBJECTIVE: To evaluate the efficiency of adaptive rate dual-chamber pacing to control the recurrence of atrial arrhythmias in patients with the brady-tachy variant of the sick sinus syndrome (SSS) with or without associated AV block.

METHOD: A total of 23 patients were included in this double-blind, randomised, crossover study. In each patient a CPI 1230 dual pacemaker was implanted. The pacemaker was programmed blind to the investigator in a randomised order to four different pacing modalities for a period of four weeks each: DDD, lower rate 60 PPM; DDD, lower rate 80 PPM; DDD-R, lower rate 60 PPM; and DDD-R, lower rate 80 PPM. The incidence of atrial tachyarrhythmia events was determined by interrogating the event counter of the pacemaker, 24-hour Holter monitoring in each mode and documentation of the need for reprogramming, electro-cardioversion and antiarrhythmic medication. The quality of life in each pacing mode was assessed by quality-of-life questionnaires and patient diaries.

RESULTS: None of the pacing modes were significantly better for the whole patient group with respect to the suppression of atrial arrhythmias. However, there were significant individual differences in the occurrence of atrial tachyarrhythmias and tolerance for each mode.

CONCLUSION: In dual-chamber pacing for patients with the brady-tachy variant of the SSS, the ideal programming cannot be predicted. Individual mode setting with usage of the pacemaker event counter should be performed to find the best antitachycardia mode.