Intercostal muscle twitching from right ventricular apical pacing.

A patient with a dilated cardiomyopathy underwent successful implantation of a cardiac resynchronization therapy defibrillator. The device system included an active fixation lead placed at the right ventricular (RV) apex. Pacing from the RV apex unexpectedly led to left-sided intercostal muscle stimulation and twitching. This intercostal muscle twitching resolved completely with movement of the lead to the RV outflow tract. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.