Heart Failure and CRT: Insights from Noninvasive ECG Imaging (ECGI)

Delayed left ventricular (LV) activation and asynchronous contraction accompany more than 30% of advanced heart failure (HF) cases. Cardiac resynchronization therapy (CRT) using biventricular pacing is an electrical approach aimed at restoring synchrony. However, detailed electrical information on the electrophysiologic substrate of HF and the effects of CRT has been limited, mostly because of the requirement for invasive mapping. Electrocardiographic Imaging (ECGI) is a method for noninvasive epicardial electrophysiologic mapping, developed in our laboratory. In my presentation, I will describe ECGI images of native cardiac activation in patients with both ischemic and nonischemic cardiomyopathy, and how they are altered by CRT. The results may provide new insights into yet unresolved issues such as patient selection for CRT, lead placement, efficacy of LV pacing alone, and why CRT is not beneficial in 30% of patients. References: 1. P. Jia, C. Ramanathan, R.N. Ghanem, K. Ryu, N. Varma, Y. Rudy. Electrocardiographic Imaging of Cardiac Resynchronization Therapy in Heart Failure: Observations of Variable Electrophysiological Response. Heart Rhythm 2006;3:296-310. 2. S. Ghosh, J.N.A. Silva, R.M. Canham, T.M. Bowman, J. Zhang, E.K. Rhee, P.K. Woodard, Y. Rudy. Electrophysiological Substrate and Intraventricular LV Dyssynchrony in Non-ischemic Heart Failure Patients Undergoing Cardiac Resynchronization Therapy. Heart Rhythm 2011;8:692-699.