Influence of the atrio-ventricular delay optimization on the intra left ventricular delay in cardiac resynchronization therapy

Abstract

Background: Cardiac Resynchronization Therapy (CRT) leads to a reduction of left-ventricular dyssynchrony and an acute and sustained hemodynamic improvement in patients with chronic heart failure. Furthermore, an optimized AV-delay leads to an improved myocardial performance in pacemaker patients. The focus of this study is to investigate the acute effect of an optimized AVdelay on parameters of dyssynchrony in CRT patients.

Optimal Atrioventricular Delay in CRT Patients Can Be Approximated Using Surface Electrocardiography and Device Electrograms

“…5). Previous publications have examined the effect of programming AVDs 50 ms longer or shorter than the optimal value and have demonstrated that the short AV delays produce significantly inferior EF 7 and cardiac output 30 . In the present study 30 ms was chosen as the hemodynamically significant deviation from the optimal AVD.…”

“…A large amount of evidence indicates significant dependence of CRT efficacy on the location of the pacing sites and relative timing of the pacing pulses 6–8 . A few single‐center studies suggested that optimization of the programmed atrioventricular (AVD) and interventricular (VVD) delays may incrementally improve the long‐term outcome of the biventricular pacemaker therapy 9–11 .…”

Cardiac Resynchronization Therapy Optimization Using Noninvasive Cardiac Output Measurement

“…Device optimization is practiced routinely only by a minority of implanting centers and those physicians who do perform it restrict this to patients who initially fail to respond to CRT 19 . A number of studies have shown that AV, and to a lesser extent VV delay optimization, have potential clinical benefits 11, 12, 27, 28 . From a purely physiological point of view, the optimal AV delay should enable the completion of passive LV filling prior to active filling by left atrial contraction to be followed immediately by ventricular systole.…”

Interatrial Conduction Correlates with Optimal Atrioventricular Timing in Cardiac Resynchronization Therapy Devices

“…The optimal device AV delay can be determined by either accounting for these factors 12 or, alternatively, by iterating through a number of device settings and evaluating cardiac function at each. Earlier publications have indicated that interatrial conduction time (IACT), defined as the delay between the activation of the right and left atria, may be an important determinant of the optimal AV delay 12,13 . We have previously reported a positive correlation between IACT and optimal AV during atrial pacing 14 .…”