[2 cases of agenesis of the left coronary trunk in adults]

Agenesis of the left main coronary artery is a congenital condition the prognosis of which is reputed to be good in adults, provided no associated heart disease is present. The first case reported here illustrates the benign character of the anomaly. In contrast, the second case shows that when associated with proximal atheromatous stenosis of the single right coronary artery the anomaly may have catastrophic consequences. The anatomical variants and morbid associations of left main coronary artery agenesis are described.