RESUMO
INTRODUCTION: Total occlusion of the left main coronary artery is a very rare finding in coronary angiography because of its highly lethal nature. Right coronary artery dominance and extensive collateral circulation are the principal determinant factors of survival after total occlusion of the left main coronary artery. The impact on the left ventricle is often significant with a profound alteration of its systolic function. CASE PRESENTATION: We describe a 52-year-old North African man, a tobacco smoker, who presented symptoms of unstable angina related to a total chronic occlusion of his left main coronary artery with a right coronary artery stenosis. Unexpectedly, the impact on his left ventricle was absent with normal dimensions and systolic function. He underwent a successful on-pump coronary artery bypass grafting with uneventful postoperative course and good recovery. CONCLUSIONS: Total occlusion of the left main coronary artery is a rare condition, the fact that the left ventricle retains a normal size and systolic function makes it exceptional, which must be kept in mind to avoid dangerous examinations and delayed treatment. Coronary artery bypass surgery should be considered the main treatment of total chronic occlusion of the left main coronary artery.