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Background: Positive electrocardiogram (ECG) changes in patients with unstable angina or non-ST elevation myocardial infarction are well known, but problem arises when no specific changes in ECG are identified. The aim of this study is to evaluate the prevalence of these changes in hospitalized patients at Amir Kabir Hospital of Arak. Materials and Methods: This study was a cross-sectional one that was conducted on 124 patients hospitalized at the heart emergency ward of Arak Amir Kabir Hospital with unstable angina and non-ST elevation myocardial infarction. ECG changes and serum cardiac enzyme levels were analyzed on admission and 12 hours after admission. Results: According to patients’ history and serum cardiac enzymes, 62 patients had undergone myocardial infarction without ST segment elevation, 98.4% of whom had ECG changes and 1.5% showed no ECG changes. Of the 60 patients, who had been hospitalized with unstable angina, 90% showed ECG changes and the rest 10% revealed no such changes. Conclusion: In comparison to other studies reporting that 50% of patients with unstable angina and non ST elevation myocardial infarction reveal no ECG changes, a high percentage of patients referring with a chest pain to the heart emergency ward of Amir Kabir Hospital, had no significant changes in their ECG and were not hospitalized.

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Background: Left main coronary artery divides into left anterior descending and circumflex arteries. Total occlusion of the left main coronary artery without extensive MI and cardiogenic shock is a rare finding. Case: The patient is a 50-year-old man that had referred to doctor’s office with history of exert ional chest pain two months earlier. Although he did not have history of rest angina, he had history of smoking as well as positive family history for coronary artery diseases. Exercise test with echocardiography revealed significant S-T depression. Hence, coronary angiography was done for the patient which showed total occlusion of the left main and originated left circumflex artery from right coronary artery and left anterior obliq filled from right coronary artery. The patient was candidate for coronary artery bypass graft. Conclusion: Total occlusion of the left main coronary artery without cardiogenic shock and death is a rare finding. This phenomenon occurs when occlusion is chronic and it is followed by right coronary artery with well-developed collateral which might be presented with stable angina. The mainstay treatment for total occlusion of the left main coronary artery is coronary artery bypass graft