PREDICTING CHRONIC OPTIMAL A-V INTERVALS FOR BIVENTRICULAR PACING VIA OBSERVED INTER-ATRIAL DELAY

摘要

Herein provided are methods for optimizing the atrio-ventricular (A-V) delay for efficacious delivery of cardiac resynchronization therapy. The A-V delay is set such that pacing-induced left ventricular contraction occurs following completion of left atrial (LA) contraction. This maximizes left ventricular filling (preload) which theoretically results in optimal LV contraction via the Frank-Starling mechanism. In CRT devices, the programmed A-V delay starts with detection of electrical activity in the right atrium (RA). Thus, a major component of the A-V delay is the time required for inter-atrial conduction time (IACT) from the RA to the LA. This IACT can be measured during implantation as the time from the atrial lead stimulation artifact to local electrograms in a coronary sinus (CS) catheter. Assuming that the beginning of LA contraction closely corresponds with the beginning of LA electrical activity, the optimal AV delay should be related to the time between the start of RA electrical activity and the start of LA electrical activity plus the duration of LA atrial contraction. Thus the inventors hypothesized that during atrial pacing the IACT measured at implantation correlated with the echocardiographically defined optimal paced AV delay (PAV).