Alternatives when coronary sinus pacing is not possible.

Biventricular pacing via a branch vein of the coronary sinus is not always possible due to anatomical reasons including phrenic nerve stimulation, scarred myocardium unable to sense or pace, and distorted anatomy prohibiting entry into the coronary sinus. Three patients are described in which alternative site pacing with an electrode in the right ventricular outflow tract alone or as a part of biventricular pacing system in the right ventricle provided a major improvement in dyspnea, congestive heart failure, New York Heart Association functional class, and ability to ambulate.