Giant Coronary Arterial Aneurysm of the Proximal Left Anterior Descending Artery as the Cause of Wide Splitting of the Second Heart Sound

Even in modern clinical cardiology, basic auscultation skill is not obsolete and is still important because it can always provide a clue to an underlying pathophysiology. We demonstrate an unusual mechanism of pathological wide splitting of the second heart sound due to external compression of the pulmonary trunk in a patient with a giant coronary arterial aneurysm of the proximal left anterior descending artery. Echocardiography, when combined with a three-dimensional anatomical analysis with cardiac computed tomography, was useful for elucidating the mechanism of the abnormal heart sounds.