A 57 year old male smoker, with a long history of hypertension, presented with angina. The physical examination was unremarkable. An ECG showed sinus rhythm and T inversion over lateral leads. A coronary angiogram (panel A) showed normal left anterior descending (LAD) and circumflex arteries. An extremely tortuous coronary fistula forming multiple loops was observed. The origin of the fistula from the LAD was not clearly seen from multiple views and it appeared to drain into the coronary sinus.

A contrast enhanced multislice spiral computer tomography (MSCT) with retrospective ECG gated reconstruction was performed to delineate the site of origin and termination of the fistula. Multiplanar reconstruction images showed the fistula originated from a diagonal branch of LAD and it formed multiple loops before terminating in the left ventricular cavity (panels B, C).

The patient underwent exercise thallium which was negative for myocardial ischaemia. In view of the stable angina, absence of heart murmur, and no objective evidence of coronary artery steal, the patient was managed conservatively.

Coronary–cameral fistulas are often caused by aberrancies of normal embryological development. Major sites of origin of fistula are the right coronary artery (55%), left coronary artery (35%), and both coronary arteries (5%). Major termination sites are the right ventricle (40%), right atrium (26%), pulmonary arteries (17%), and less frequently the superior vena cava or coronary sinus, and least often the left atrium and left ventricle. The resultant physiologic derangement depends upon the site of origin and termination of the fistula and the size of the connection. The current case demonstrates that the size and anatomical features of a coronary–cameral fistula can be reliably established by MSCT, as opposed to conventional methods such as coronary angiography or with retrograde thoracic and aortic root aortography.

Selective angiography of the left main coronary artery from right anterior oblique view.

Three dimensional reconstruction image of multislice spiral computed tomography (MSCT) showing the origin of the coronary fistula from the dilated diagonal branch and the small left anterior descending coronary artery distal to the site of origin.

Sagittal view of MSCT showing coronary fistula terminating in the left ventricular cavity.