Coronary Sinus Catheter-Induced Heart Block During Aortic Valve Replacement: A Case Report

: Conduction abnormalities after cardiac surgery are common as is spontaneous resolution of these abnormalities. However, 1%-3% of patients will require placement of a permanent pacemaker. Patients with preexisting conduction abnormalities, undergoing reoperation, preexisting pulmonary hypertension and undergoing mitral or aortic valve operations are at a higher risk for requiring a permanent pacemaker. We present the first case described in the literature of a patient with a preexisting left bundle branch block, and heart failure with a reduced left ventricular ejection fraction of 25% who developed complete heart block after placement of a coronary sinus catheter.