Angina pectoris due to possible vasospasm of small coronary arteries

Recently, the presence of vasospasm in small coronary arteries is speculated in animals and humans. A 40-year-old female patient complained of chest pain at rest. Left ventriculogram showed normal wall motions. Left and right coronary arteries were also normal. After methylergometrine maleate was selectively administered to a right coronary artery, she complained of chest pain, and ST-segment elevation was detected in leads II, III, and aVF of ECG. Right coronary arteriography was performed immediately, but no coronary stenosis was found. The next day, methylergometrine maleate was again administered intravenously and the patient complained of chest pain, but no ischemic changes were observed in ECG. Thallium-201 myocardial scintigraphy followed immediately. Apical perfusion defect was detected in stress image. In the delayed image, it showed complete redistribution. Three days later, catheterization and scintigraphy were performed at the same time. When methylergometrine maleate was administered to the left coronary artery, she complained of chest pain within a few minutes of the injection; however, ECG remained unchanged. 201Tl myocardial scintigraphy was performed immediately. In the stress image, it showed apical perfusion defect as shown in the intravenous methylergometrine maleate injection study. It also showed complete redistribution in the delayed image. Apical perfusion defect can be attributed to myocardial ischemia of left coronary artery, which are too small to be detected by conventional coronary arteriography. Vasospasm in small coronary arteries may be involved in this phenomenon.