Mechanical dyssynchrony indices from an electrophysiological contact mapping system predict response to CRT

We present a methodology to extract mechanical dyssynchrony indices from an electrophysiological (EP) contact mapping system that was applied to a database of ten patients undergoing Cardiac Resynchronization Therapy (CRT), before and after the therapy. The mechanical dyssynchrony indices were obtained after post-processing high temporal resolution data recorded at several endocardial positions with the measuring catheter of the EP system. Velocity profiles of these catheter trajectories were analyzed to identify abnormal patterns of motion such as septal flash, whose presence is strongly related to a positive response to CRT in patients with left bundle branch block. Septal flash motion was identified in four cases, which was qualitatively validated by visual inspection of imaging data, and a strong correlation with response to CRT was observed a posteriori. Finally, the effect of biventricular pacing was clearly observable by a substantial reduction of the septal flash