Patients, mean age 70 years, with automatic implantable cardioverter-defibrillators treated with dual-chamber rate responsive pacing (DDDR-70) have a higher mortality than patients with backup ventricular pacing (VVI-40) at 3.7-year follow-up.

Background. One study showed in 506 patients with automatic implantable cardioverter-defibrillators (AICDs) that the mortality at 1-year follow-up was 6.5% with ventricular backup pacing at 40/minute (VVI-40) versus 10.1% in patients with dual-chamber rate responsive pacing at 70/minute (DDDR-70). Methods. We performed a retrospective study to determine all-cause mortality in all patients at a university hospital who had AICDs without indications for antibradycardia pacing. Of 535 patients, mean age 70 6 12 years, 271 patients had backup ventricular pacing with a VVI-40, and 264 patients had dual-chamber rate responsive pacing with a DDDR-70. Results. At 3.7-year mean follow-up, all-cause mortality was 19% (50 of 264 patients) in patients with DDDR-70 pacing versus 11% (29 of 271 patients) with VVI-40 pacing (p , .01). Conclusion. Because of the increased mortality, increased cost, and complexity for dual-chamber rate responsive pacing in patients with AICDs, concomitant DDDR pacing at a rate of 70/minute in patients without an indication for antibradycardia pacing is not warranted.