Nonatherosclerotic Coronary Angina: Lung Steals Blood From the Heart

Abstract

INTRODUCTION: Angina occurs when myocardial oxygen demand exceeds oxygen supply; the clinical manifestation is often chest discomfort. Several non-atherosclerotic conditions have been studied and reported in literature that cause angina in rarity. CASE PRESENTATION: A 40 year old Chinese healthy male presented to the emergency department with chest pain described as heavy, retrosternal, non-radiating, constant for 30 minutes associated with dizziness, nausea and palpitations which started while lifting a weight of 40 pounds. It relieved gradually with rest. His physical activity was limited due to the chest discomfort (CCS Class II angina). He had a smoking history of 10 packs per day without alcohol or illicit substance use and an insignificant family history. His physical exam was positive for grade II/VI continuous murmur at the left sternal border, with clear lungs and normal jugular venous pressure. His exercise stress test which was terminated at 7 minutes as he developed dizziness, ST segment depression in the lateral leads along with non-sustained ventricular tachycardia and a transient left bundle branch block. Cardiac catheterization showed insignificant coronary artery disease but revealed a fistula leading from the Left anterior descending (LAD) to the main pulmonary artery. This was confirmed by Coronary CT angiogram coursing within the epicardial fat along the lateral aspect of the pulmonary outflow tract. An attempt to coil the fistula via the pulmonary circulation was unsuccessful. Robotic arm assisted ligation in the operating room showed a 1-cm long feeding vessel coming off the LAD with only one visualized branch, which was isolated and ligated close to the LAD. TEE was used to confirm the presence and absence of flow. This resulted in patient recovery without any complications. DISCUSSION: A coronary artery fistula (CAF) is an abnormal communication between an epicardial coronary artery and a cardiac chamber or a major vessel. They may present at any age and are mostly congenital. Whether or not a patient will develop symptoms depends on the degree of volume overload and severity of the left to right shunt. Coronary angiography still remains the gold standard for diagnosis. Surgical ligation and transcatheter embolization are known treatment options for CAF. CONCLUSIONS: Our patient presented with symptoms of stable angina, further unmasked during exercise stress testing. His symptoms are explained by the â€steal†phenomenon where coronary blood flow is shunted to the pulmonary artery at the expense of myocardium, resulting angina. Symptoms abated after successful ligation of the fistula using a robotic arm.