Left ventricular regional remodeling and lead position during cardiac resynchronization therapy

During CRT, systolic WT increases in segments remote to LV-LP, decreases in concordant segments, and remains unchanged in adjacent segments. Only marginal changes occur in wall thickness. In nonresponders with nonischemic cardiomyopathy, deleterious changes in segmental myocardial function occur, and further studies on how to treat these patients best are warranted.