Left Coronary Artery Circumflex Branch Arising From Main Stem of Pulmonary Artery: An Uncommon Anatomical Variation.

The left circumflex coronary artery anatomy is considered highly variable. Herein, we present a case of a 9-year-old male child with a remarkable medical history of a spontaneously closed interventricular septal defect, without residual regurgitation, who was referred for cardiological evaluation in view of orthopedic surgery. During the preoperative examination, echocardiography was performed, which showed multiple flows in the interventricular septum as well as a diastolic flow at the level of the pulmonary valve. Due to these findings, it was decided to perform a cardiac catheterization. On cardiac catheterization, it was diagnosed an anatomical variation of the circumflex branch of the left coronary artery arising from the main stem of the pulmonary artery. Significant stenosis was remarkable, as well as collateral circulation of both the circumflex and the left anterior descending artery with the right coronary artery. The child finally at the age of 11 underwent cardiothoracic surgery. To conclude, during asymptomatic cardiological evaluation, we should always think about the possibility of anatomic variations of the coronary arteries. Missing these types of anomalies may predispose to inadvertent life-threatening complications or sudden death.