Case Presentation: The incidence of congenital coronary artery anomalies has been estimated at approximately 1%. Although the majority of anomalies are benign, some are life-threatening. Malignant aberrant vessels passing between the aorta and pulmonary trunk are at risk for sudden death, especially in the left coronary artery distribution.
A 34 year old Caucasian female with a relevant history of COPD, iron deficiency anemia, bipolar disorder, alcohol and tobacco abuse presented to the emergency department with a four month history of chest tightness and dyspnea associated with lightheadedness on exertion and increased anxiety. Physical examination and laboratory results were unremarkable; electrocardiogram (ECG) showed a normal sinus rhythm. She declined further workup and was discharged. Due to ongoing symptoms, three months later the patient agreed to a myocardial perfusion scan with adenosine which showed a normal ejection fraction and multiple reversible defects in the left anterior descending and left circumflex territories. A subsequent coronary CT angiogram (CCTA) revealed an anomalous origin and course of the left main coronary artery (LMCA). The patient’s LMCA arose from the right coronary cusp and ran between the aortic root and pulmonary outflow tract and arrived in the superior aspect of the interventricular groove. A cardiac catheterization confirmed the anomalous LMCA and she was referred to a tertiary level center for further management. Due to the position of the LMCA, a coronary artery transplant could not be performed; she underwent a coronary artery bypass graft and had an uncomplicated post-operative course.
Discussion: Although most coronary artery anomalies are asymptomatic and do not require intervention, some aberrancies are malignant; they impede myocardial perfusion and can lead to myocardial ischemia or sudden cardiac death. Patients with malignant aberrancies often have unremarkable exam findings, laboratory studies and ECG. Some patients may have a positive stress test with the coronary anomaly identified on CCTA and confirmed on cardiac catheterization. The standard management is surgical intervention; usually a coronary artery transplant is performed unless there is an anatomical barrier which necessitates another approach. Compared to our patient’s aberrant LMCA, a normal LMCA originates just superior to the left cusp of the aortic valve and travels along the atrioventricular groove and does not pass between the aorta and pulmonary arteries. Our patient’s anomalous LMCA had a malignant intra-arterial course which carried a high risk for sudden cardiac death and necessitated urgent identification and intervention.
Conclusions: Physicians should keep congenital coronary artery anomalies in their differential for patients who present with persistent cardiac complaints.