Effect of different atrioventricular delays in patients with dual chamber pacing on left ventricular function at rest: echo-doppler study

ABSTRACT

In presence of normal SA node function, VDD mode, is often the most efficient means to pace the heart in a truly physiological pattern. In this study, Doppler echocardiography has been used to assess at rest both cardiac systolic and diastolic functions during VDD mode of pacing at different atrioventricular delays [AVD] and VVI mode at the same rate. In conclusion, this study confirms the hemodynamic benefit gained by patients with complete A-V block from the dual chamber mode of pacing, and demonstrates the simplicity, reliability and reproducibility of the echo-Doppler study in assessment of myocardial performance and the necessity of atrial systole. The study also stressed the importance of a properly timed atrial contraction, and that there is an optimal AV delay at which myocardial function is at its maximum. Finally, the interindividual variability of the optimal AV delay has been confirmed