Ventricular fibrillation with diminished internal mammary artery graft flow during sternal retraction.

Ventricular fibrillation is a common arrhythmia encountered after the termination of cardiopulmonary bypass. Risk is augmented in patients who are undergoing repeat cardiac procedures with most documented complications occurring during repeat sternotomy. Aortic valve surgery is more complex after coronary artery bypass grafting using internal mammary arteries, and it compounds the increased risk of repeat sternotomy. This case report describes a low-flow state artificially created by sternal retraction applying tension on a right internal mammary artery to posterior descending artery anastomosis, with resultant unrecognized myocardial ischemia yielding refractory ventricular fibrillation during aortic valve replacement.