Coronary spasm-related acute myocardial infarction in a patient with essential thrombocythemia.

We report a case of essential thrombocythemia (ET) in a 30-year-old female who exhibited inferior wall ST-elevation acute myocardial infarction (AMI) without significant obstructive coronary artery disease. Right coronary vasospasm was observed after intra-coronary methylergonovine administration and she received verapamil 120 mg/dthereafter and hydroxyurea 1500 mg/d for thrombocythemia. After discontinuation of the hydroxyurea for 9 mo based on the impression of coronary spasm-related instead of coronary thrombosis-related AMI, her platelet count rose but no chest pain was observed. It is suggested that coronary spasm potentially plays a role in patients with ET, AMI and no significant coronary artery stenosis.