Analysis of body surface potential maps in cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) aims at improving systolic function inpatients with heart failure. We investigated the use of body surface potential mapping (BSPM) in the understanding of the activation sequence in the myocardium during biventricular (BiV) pacing. We acquired BSPM recordings in 29 patients with an implanted BiV device during normal sinus rhythm, right ventricular (RV) pacing, left ventricular (LV) pacing and BiV pacing. We compared potential maps during BiV pacing to those during R V pacing and L V pacing by a 2-D correlation. By studying BSPM maps, we observed that 38% of our patients presented potential maps similar to those observable when pacing with a single lead. These patients may not be taking full advantage of the potential benefits of CRT.