Arteriovenous connection between the aorta and the coronary sinus through a giant fistulous right coronary artery.

Coronary arteriovenous fistulas are rare. The right coronary artery (RCA) seems to be the most common site of origin, while the right ventricle, right atrium and the main pulmonary artery are the most common draining chambers. We report on a patient with fistulas in both coronary arteries: one arising from the circumflex artery and draining into the coronary sinus (CS), and a fistulous connection between the proximal aorta and the CS, represented by an enlarged and cirsoid RCA. Despite the factthat the non-invasive diagnosis of coronary fistulas has traditionally been difficult, in this case echocardiography led to the suspicion of the anomaly.