Echocardiography for determining the optimal atrioventricular interval in patients with dual chamber pacemakers.

Background: We investigated the clinical value of Doppler echocardiography for determining the optimal setting of atrioventricular interval in patients with dual chamber pacemakers (DDD). In 38 patients with complete atrioventricular block and DDD pacemakers, the atrioventricular interval was prolonged in a stepwise fashion by 20 ms, from 90 to 250 ms, and cardiac stroke volume and transmitral flow were measured by pulsed Doppler echocardiography. Methods: The optimal atrioventricular interval at which the cardiac stroke volume was maximal was 168.9 +/- 15.6 ms. The atrioventricular interval was 178.4 +/- 23.4 ms when the end of the A wave coincided with complete closure of the mitral valve. Results: There was a significant linear relationship between the optimal atrioventricular interval and the predicted optimal atrioventricular interval (Y = 86.2 +/- 0.5X, r = 0.70, standard error of the estimate [SEE]= 11.5, P < 0.01). Conclusion: The optimal atrioventricular interval setting for DDD pacing can be successfully determined using Doppler echocardiography, which is a noninvasive, repeatable, and simple approach.