[Spasm of the left main coronary artery resistant to intracoronary vasodilators. Apropos of a case].

Coronary spasm is essentially and angiographic diagnosis. Catheter-induced spasm is frequent during coronary angiography and usually regresses after the administration of intracoronary vasodilators. The authors report a case of coronary spasm with subocclusion of the left main coronary artery: the coronary narrowing remained significant after intracoronary vasodilator therapy, suggesting an organic component. The spasm was relieved only after a prolonged intravenous infusion of isosorbide dinitrate.