Coronary artery spasm has been proposed as a definite cause of vasospastic angina and as a contributor to other acute cardiac events, including unstable angina, acute myocardial infarction, and sudden cardiac death. It has also been demonstrated that silent ischaemia caused by coronary artery spasm could initiate potentially fatal arrhythmias in patients without flow limiting structural coronary artery lesions. We report a case of prolonged sinus arrest after an attack of coronary artery spasm.

A 50 year old woman presented with recurrent spontaneous chest pain that usually occurred in the morning. She had been diagnosed as having hypertension two months previously without taking any medication. Resting ECG showed normal sinus rhythm without ST-T wave change (panel A). Treadmill exercise test with Bruce protocol showed no significant ST change with good exercise tolerance. Holter monitoring was applied, during which the patient had severe chest pain followed by syncope at midnight. Holter monitoring during chest pain showed pronounced ST segment elevation (panel B) followed by bradycardia (panel C). After normalisation of ST segment elevation, prolonged (28 seconds) sinus arrest followed (panel D), which was the cause of her syncope. Coronary angiography showed no significant luminal narrowing. The patient was treated with a calcium channel blocker and nitrates, with a subsequent uneventful clinical course.