Left Main Coronary Artery Fistula Presenting as Heart Failure: A Case Report

Area of Science:

• Cardiology
• Cardiovascular Surgery
• Medical Imaging

Background:

• Coronary artery fistulas (CAFs) are uncommon abnormal connections between coronary arteries and heart chambers/vessels.
• While often congenital, CAFs can be acquired and typically cause a left-to-right shunt.
• Larger fistulas may lead to heart failure, ischemia, or atrial enlargement, necessitating intervention.

Purpose of the Study:

• To report a case of a massive left atrial dilation and heart failure caused by a left-main-coronary-artery-to-left-atrium fistula.
• To highlight the importance of considering CAFs in unexplained cardiac chamber enlargement and heart failure.

Main Methods:

• A 44-year-old woman with a history of cardiothoracic surgery presented with heart failure and massive left atrial dilation.
• Multimodal imaging identified a large left main coronary artery aneurysm with a fistula to the left atrium.
• Surgical repair involved aneurysm resection, graft replacement, fistula closure, and left atrial appendage exclusion.

Main Results:

• The patient had a large left main coronary artery aneurysm (6.0 cm) with a significant fistula to the left atrium.
• This resulted in massive left atrial dilation, high prosthetic mitral valve gradient, pulmonary hypertension, and reduced ejection fraction.
• Post-surgical repair, her symptoms resolved, and cardiac function improved.

Conclusions:

• Unexplained cardiac chamber enlargement and heart failure warrant investigation for coronary artery fistulas.
• Coronary artery fistulas are a treatable cause of heart failure that can be overlooked.
• Prompt diagnosis and surgical management of CAFs can lead to significant clinical improvement.