Iatrogenic left main coronary artery stenosis.

Iatrogenic left main coronary artery stenosis is a potentially life-threatening complication of cardiac valve replacement surgery due to injury by perfusion cannulas. This requires prompt clinical recognition and diagnosis by repeat coronary angiography, and treatment by early coronary artery bypass grafting. We present 3 patients who had normal coronary arteries prior to valve replacement surgery, and who developed severe left main coronary artery stenosis after surgery. Accelerating angina and refractory ventricular arrhythmia were presenting clinical manifestations. Coronary artery bypass grafting was successfully performed in all 3 patients.