Abstract 14549: Malignant Anomalous LMCA With an Interarterial Course: Atypical Presentation

A 42-year-old healthy female presented to the emergency department with coughing and shortness of breath, complicated by syncope. Before loss of consciousness, the patient reported feeling lightheaded, but no chest pain or palpitations were appreciated. Following a negative work up for cardiogenic syncope, she was discharged home with a presumed diagnosis of vasovagal syncope. Over the next 12 months, the patient had recurrent episodes of shortness of breath followed by either a presyncopal prodrome or full syncopal episodes. Each episode came on with coughing and dyspnea without significant exertion. 18 months after the original event, she was re-evaluated for cardiac etiologies of her symptoms, and CT coronary angiogram showed an anomalous left main coronary artery arising from the right coronary cusp (AAOLCA) with an interarterial course, which was subsequently confirmed on coronary angiography (figure 1). Anomalous Left Coronary Arteries of Aortic Origin (AAOLCA) present a diagnostic dilemma for cardiologist, given their vague presenting symptoms, unknown prevalence in the general population, and high risk for Sudden Cardiac Death (SCD). This patient’s syncopal episodes and presyncopal symptoms that were inconsistent with a cardiac etiology represent an atypical presentation, although there is no classic presentation for which AAOLCA is the most likely diagnosis. AAOLCA’s with an interarterial course, as seen in this patient, account for the majority of SCD caused by anomalous coronary arteries, despite making up just 1.3% of all identified cases. Referral for surgical correction is recommended for all patients AAOLCA with an interarterial course, to reduce risk of SCD. Further research is warranted regarding the true prevalence of AAOLCA in the general population, the risk of SCD associated with various AAOLCA’s, and validated screening tools for utilization of coronary CTA or MRA to identify AAOLCA’s prior to major cardiac events.