AV DELAY OPTIMIZATION AND MANAGEMENT OF DDD PACED PATIENTS WITH DILATED CARDIOMYOPATHY

Ten DDD paced patients, suffering from dilated cardiomyopathy in the N YHA functional classes III or IV were studied by means of Doppler echo cardiography at different programmed values of atrioventricular (AV) d elay (200, 150, 120, 200, and 80 msec). The following variables were e valuated: LV diameter, ejection fraction, mitral and aortic flow veloc ity integrals, and stroke volume. During VDD pacing, a resting AV dela y associated with the best diastolic filling and systolic function was identified and programmed individually. Shortening of the AV delay to about 200 msec was associated with a gradual and progressive improvem ent. Further decrease ca used an impairment of systolic function. The patients were clinically and hemodynamically reevaluated after 2 month s of follow-up. A reduction of NYHA class and an improvement of LV fun ction were consistently found. The reported data suggest that programm ing of an optimal AV delay may improve myocardial function in DDD pace d patients with congestive heart failure. This result may be the conse quence of an optimization of left ventricular filling and a better use of the Frank-Starling law.