The study of a case of single coronary artery using stress 201thalium single photon emission computed tomogram

A 48-year-old female, who had been having episodes of chest discomfort and oppression lasting for several minutes for 15 years was diagnosed as having a single left coronary artery by coronary angiography. The electrocardiogram taken during a chest pain attack demonstrated the depression of the ST-segment in leads II, III, aVF, and V4-6. The chest pain was relieved, and the ischemic change in ECG was improved by sublingual nitroglycerine. 201Thalium single photon emission computed tomography under stress indicated poor uptake in both the anterior and infero-posterior myocardium, which was compatible with the change in ECG either during the attack or during exercise. The anterior myocardial ischemia was reduced by propranolol and the chest pain was successfully relieved by propranolol. The chest pain in this case might have partly been due to the myocardial ischemia in the anterior and infero-posterior myocardium, under stress, which could have been the steal phenomenon to lateral myocardium due to the anatomical anomaly, besides other possible mechanisms for chest pain proposed in the case of single coronary artery. Our findings suggested that 201Thalium stress single photon emission computed tomography is a useful method for detecting the myocardial ischemia in patients with single coronary artery and those suffering from chest pain without any coronary stenosis.