[Unstable angina pectoris--combination of an epicardial stenosis and a Prinzmetal spasm]

A 61-year-old man presented with recurrent angina pectoris at rest for 3 days. The medical history revealed hypertension and an elevated cholesterol level as cardiovascular risk factors.

The physical examination revealed no pathological findings. ECG at admission showed no signs of ischemia, while high-sensitive Troponin T was slightly elevated. Echocardiography showed diastolic dysfunction and biatrial dilatation.

During another episode of angina at rest, ECG showed T-wave inversion in lead aVL. Therefore, coronary angiography was performed. At the beginning of the examination the patient complained of angina at rest and ECG showed ST-elevation in the inferior leads. Coronary angiography revealed a subtotal stenosis in the middle part of the RCA. After intracoronary nitroglycerin injection there was a high-grade stenosis in this region. An intracoronary acetycholin provocation test was performed which reproduced a focal spasm in the area of the RCA stenosis with simultaneous changes in the ECG and reproduction of the patient's unusual angina. After implantation of a bare metal stent a subsequent ACH-test did not elicit any further coronary spasm. Four weeks after the procedure the patient had no further complaints under medical treatment.

This case illustrates a patient with a focal Prinzmetal-type spasm with ST-elevation on top of a high-grade stenosis of the right coronary artery as an explanation for the unstable angina. Coronary spasm of the Prinzmetal-type can occur in vessels with epicardial stenosis as well as in vessels without stenosis. In some cases focal coronary spasm can be prevented by the implantation of a stent.