Bibliogr. s.531

BACKGROUND: Absence of the left circumflex artery (LCX) is an extremely rare congenital anomaly of the coronary circulation. While some coronary circulation anomalies are associated with significant complications, including sudden cardiac death and premature atherosclerosis, absence of the LCX is largely considered benign, though it has been associated with exertional chest pain, which may mimic acute coronary syndrome. Diagnosis is made when heart catheterization is performed in the work up for acute coronary syndrome or when computed tomography coronary angiography is performed during evaluation of coronary artery disease. CASE REPORT: We report a 55 year old female who presented with non-exertional chest pain in the setting of an emotional stressor. The initial work up was only significant for elevated troponins, and subsequent left heart catheterization revealed findings consistent with congenital absence of the LCX. No significant stenosis was appreciated, and no intervention was performed. Following catheterization, the patient’s troponins began to trend down, and her chest pain resolved. CONCLUSIONS: Congenitally absent LCX is a rare entity detected when work up is performed to rule out acute coronary syndrome in patients presenting with exertional chest pain. This is the first reported case of chest pain unrelated to physical activity reported in a patient with an absent LCX. There is no specific treatment for an absent LCX; however, proper identification of this anomaly and differentiation from complete occlusion of the LCX is important in making an accurate diagnosis of myocardial ischemia and for choosing the best intervention when ischemia is present.