A Case of Coronary Cameral Fistula with associated Aneurysm: Role of MDCT in diagnosis
A coronary cameral fistula (CCF) is an abnormal communication between a coronary artery and any cardiac chamber . CCF is an uncommon disorder with an incidence of 0.1% in patients undergoing coronary angiography . Although most patients are asymptomatic, it can lead to symptoms of angina pectoris. Commonly the right coronary artery is affected, although left sided coronary artery fistulae are well documented .Multiple fistulae may also occur. Over 90% of fistulae drain into the right side of the heart and therefore cause a shunt. Chronic large volume shunts through these fistulae may cause major aneurysmal enlargement of the proximal feeding coronary artery in addition to enlargement of the receiving vessel or chamber.The uninvolved coronary artery and chambers are usually normal . Most CCFs are reported as congenital and have only rarely been reported as acquired. Coronary cameral fistula with associated aneurysm (CCFAA) is even rarer.Multiple fistulae or multiple entry points may also occur, which affect the surgical management and can rarely be missed on catheter angiography. The termination sites of CCFs in decreasing order of frequency are the right ventricle, right atrium and left ventricle. Traditional imaging techniques to diagnose a coronary cameral fistula include echocardiography and catheter angiography. However, echocardiography is operator dependent and limited by availability of a good acoustic window, and it may not show the entire course of the fistula. Catheter angiography is invasive and overlaps between a tortuous fistula and adjacent cardiovascular structures may hamper complete evaluation of the lesion. Amongst recent technological advancements in cardiac imaging, MDCT is an emerging non-invasive technique for the imaging of coronary arteries because of its high contrast , spatial resolution and its capability of whole-heart volumetric acquisition in a single (10-14 seconds) breath-hold with submillimeter isotropic resolution.