Simultaneous electrical and mechanical mapping using 3D cardiac mapping system: novel approach for optimal cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) restores synchrony in heart failure patients. However, a significant proportion of patients implanted with CRT devices do not realize any benefit from CRT. Placing a left ventricular (LV) lead at the sites of electrical or mechanical delay has been advocated to maximize response to CRT, but there is currently no technique described to measure mechanical delay in real-time. We describe a novel technique that can be used intraoperatively to assess mechanical and electrical activation of the coronary sinus for guidance of LV pacing site optimization during CRT implantation.