Session S23.6

Use of Body-Surface Potential Mapping and Computer Model Simulations for Optimal Programming of Cardiac Resynchronization Therapy Devices

R Mohindra*, JL Sapp, JC Clements, BM Horacek

Dalhousie University
Halifax, Nova Scotia, Canada

Cardiac Resynchronization Therapy (CRT) is one of the prophylactic treatment options for patients suffering from heart failure and conduction block. It has been proposed that by optimizing the timing of activation between the ventricles (V-V interval), with the aid of electrocardiographic body-surface potential mapping (BSPM), the success rate of CRT devices could be improved.
We recorded 120-electrode BSPM data sampled at 2000 Hz from two patients with implanted CRT devices for V-V intervals ranging from -80 ms to +80 ms between left-ventricular (LV) and right-ventricular (RV) stimuli. Custom torso and heart geometry were extracted from CT images and were used along with second-order Tikhonov regularization to perform the inverse calculation of epicardial potentials from BSPMs. Isochrones of activation were derived from the maximum negative slope of the epicardial electrograms. As well, we used a computer model of ventricular activation to simulate activation maps for normal activation, activation with left bundle branch block and CRT pacing with different V-V intervals. From both clinically recorded and computer simulated maps, two measures of inter-ventricular synchrony were derived for a variety of V-V settings: the difference between the mean LV and RV activation times and the area between the LV and RV percent surface activated curves.
Our results obtained by inverse solution and by computer model simulations both indicate CRT pacing helped to restore the synchrony of RV and LV activation in terms of the two measures we used. As well, the computer model results provided a baseline measure by which our metrics of synchrony can be evaluated. We have demonstrated that by aiming to minimize asynchrony in ventricular activation patterns, an optimal CRT pacing V-V interval can be selected.

(Abstract Control Number: 158)