Three-dimensional transthoracic echocardiographic visualization of an aorto-left ventricular tunnel: a case report.

BACKGROUND: Aorto-left ventricular tunnel (ALVT) is a rare congenital cardiac defect consisting of an extracardiac communication between the ascending aorta and the left ventricle. It may mimic aortic regurgitation, particularly when an eccentric diastolic jet and a systodiastolic murmur are present. Accurate anatomical delineation is essential to distinguish tunnel flow from valvular regurgitation and to guide intervention. CASE SUMMARY: A 19-year-old man was referred after an abnormal murmur was detected during a routine health examination. He had no exertional symptoms or history of prolonged fever. Physical examination revealed a grade 3/6 systodiastolic murmur at the third left sternal border. Transthoracic echocardiography demonstrated a tunnel-like communication between the aortic root and the left ventricle, with abnormal eccentric flow entering the left ventricular cavity and associated aortic regurgitation. Real-time three-dimensional transthoracic echocardiography improved spatial visualization of the tunnel and its relationship to the aortic valve. Computed tomography angiography confirmed an extracardiac tunnel running near the commissural region between the right coronary cusp and non-coronary cusp, without coronary artery involvement. The lesion was classified as type I ALVT. The patient underwent surgical closure with reinforcement of the aortic annular/commissural region. Post-operative recovery was uneventful. DISCUSSION: This case highlights the value of real-time three-dimensional transthoracic echocardiography in clarifying ALVT anatomy when conventional two-dimensional imaging suggests but does not fully define the lesion. Multimodality imaging is useful for confirming the extracardiac course of the tunnel and excluding coronary involvement before intervention. Although transcatheter closure may be feasible in selected cases, surgery was selected because the tunnel was adjacent to the aortic cusp/commissural region and required direct closure with annular/commissural reinforcement.