Young man with chest pain and an abnormal echocardiogram

A man in his 40s with a history of hyperlipidaemia presented with intermittent, dull left-sided chest pain for 2 weeks that was not consistently exertional. He denied dyspnoea, cough, fevers, recent travel or exposure to sick people. He did not smoke or use alcohol or illicit drugs. There was no pertinent family history. Physical examination, an ECG, basic laboratories and a chest X-ray were unremarkable. The patient was referred for an exercise nuclear study and did 11 min on the Bruce protocol without angina or ischaemic ECG changes. Myocardial scintigraphic perfusion images at stress and rest were normal. A transthoracic echocardiogram was performed (figure 1). Figure 1 Transthoracic echocardiogram ((A) apical four-chamber view; (B) parasternal short-axis view). What is the most likely diagnosis? 1. Aortic dissection 2. Sinus of Valsalva aneurysm 3. Anomalous coronary artery 4. Unroofed coronary sinus type of atrial septal defect The echocardiogram shows the presence of an anomalous, retroaortic coronary artery sign (sensitivity 63%, specificity 94%) (figure 2A,B; …