Acute Myocardial Infarction Caused by Coronary Spasm and Dissection Treated with Medical Therapy

We report the case of a 33-year-old woman with no history of coronary risk factors or chest pain who experienced intermittent chest pain at rest for several minutes from 2 PM. At 8 AM the next day, chest pain recurred and persisted for about 1 hour. She was transported to our hospital by ambulance, where electrocardiogram showed ST-elevation in the precordial leads, and blood tests showed elevation of cardiac markers. She was diagnosed with ST-elevation myocardial infarction. Because she was a young woman without any risk factors, coronary spastic angina was suspected. Coronary angiography without intracoronary nitrate administration revealed diffuse 75% stenosis in the proximal right coronary artery (RCA) and diffuse 90% stenosis in the left anterior descending artery (LAD). A coronary spasm provocation test elicited chest pain; coronary angiography showed 99% diffuse stenosis of LAD; and electrocardiogram showed precordial ST-segment elevation. Although intracoronary nitroglycerin injection attenuated the coronary spasm in the RCA and proximal LAD, 90% stenosis and coronary dissection were observed in the midportion of the LAD. When the imaging test that was carried out before the provocation test was reexamined, the dissection was recognized, and there was no clear dissection progress after the test. Intravascular ultrasound showed dissection of the LAD, as did angiography. We treated the patient using medical therapy instead of percutaneous coronary intervention.The patient did not suffer any anginal attack and improved sufficiently to be discharged. She remained free of attacks for about 10 years to the present time, and follow-up is continuing.