A comparison of quality-of-life in patients with dual chamber pacemakers and individually programmed atrioventricular delays

Dual chamber pacemakers are increasingly implanted to achieve optimal hemodynamics by AV synchrony, but the effect of AV delay programming on the patient's quality-of-life has been less well studied. The influence of an individually programmed AV delay between 100 and 250 ms on quality-of-life was investigated in a randomized, double-blind crossover study of 13 patients (69 +/- 10 years of age) with dual chamber pacemakers implanted because of high degree AV block. During radionuclide ventriculography at rest, the ''optimal AV delay'' with the maximal left ventricular ejection fraction and the ''most unfavorable AV delay'' with the least ejection fraction were determined. The ejection fraction at rest with the ''optimal AV delay'' was 51% +/- 10%, and with the ''most unfavorable AV delay,'' 44% +/- 11% (P < 0.0001). The optimal AV delay determined by radionuclide ventriculography correlated well with the optimal AV delay determined by Doppler echocardiography using flow velocity integrals (r = 0.78, P < 0.0016). Each patient was assigned in random order to either AV delay during a 2-week period and then the pacing mode was switched for another 2-week period. At the end of each period, patients were assessed by a functional status questionnaire to assess physical capability and two further questionnaires to quantify cardiovascular symptoms or self-perceived health. There were no differences in the two AV delays regarding the patient's perceived physical capability and specific symptoms. The patient's total judgment was identical to the optimal AV delay (score 36% +/- 19%) and the most unfavorable AV delay (33% +/- 21%). Thus, in patients with a dual chamber pacemaker, an individually programmed AV delay affects left ventricular function at rest, but has no influence on quality-of-life. The determination of the flow velocity integral by Doppler echocardiography is a simple and reliable method to optimize the AV delay if necessary.