Syncope occurs frequently in adolescents, and is often benign. Potential worrisome syncopal events include those occurring with exertion, concurrent chest pain, dyspnoea or palpitations, and those with focal or diffuse neurologic changes.

A 16-year-old female was referred to our institution for a history of exercise-induced spells. She was diagnosed since the age of 2 years with neurocardiogenic syncope and postural orthostatic tachycardia syndrome. She had been evaluated at multiple institutions, and was followed by pediatric neurology for a diagnosis of migraines. Owing to recurrent worsening symptoms and a syncopal episode requiring resuscitation, an echocardiogram was performed. The right coronary was normal, but the left coronary artery ostium could not be identified well. Doppler patterns were suspicious of an abnormal left coronary artery, and computed tomography angiography was performed. This revealed a single coronary artery arising from the right aortic sinus, with the left coronary artery arising from the proximal coronary trunk and coursing through the infundibular septum. This was surgically treated utilising a left internal mammary artery bypass graft to the left anterior descending coronary artery. A year later, she has not experienced any recurrence of syncope, and has returned to athletic activity.

This case highlights the index of suspicion that must be present when evaluating any patient with syncope, both clinically and via echocardiography. A computed tomography angiogram is indicated for better evaluation of coronary artery anatomy when an anomalous coronary cannot be ruled out by echocardiography.