Name : Noshin
Affiliation : Chamran Hospital
Academic Degree: Head of Radiology Department of Chamran Hospital
Resident : Ramin Pourghorban
Gender : Female
Age : 52
52 year-old female with severe hypotension
Imaging Procedures and Findings
Axial, sagittal and coronal oblique and 3-D volume rendered CT images show a tortuous and elongated RCA with a fistulous communication to the coronary sinus. Left circumflex artery is abnormally originated from RCA. Also noted is abnormal SVC drainage to left atrium. Image 1 demonstrates tortuous coronary artery (RCA) in right anterior cardiac border. White arrow on image-1 shows the enlarged coronary sinus. Insertion of the RCA fistula (fistula neck) to coronary sinus is shown on image-3. Abnormal origin of Left circumflex artery (long arrow) from RCA is depicted on image-5. Dilated RCA is originated from right aortic coronary sinus and left anterior descending artery (LAD) has normal appearance. Images 6 and 9 reveal that SVC drains to left atrium. Anomalous LCX is also shown on images 8-9. Volume-rendered CT scan (combined image-10) better depicts the elongated and tortuous RCA.
Normal coronary arteries terminate in broom-like arborizations, which penetrate the myocardium. CAF is defined as a direct precapillary connection between a branch of a coronary artery and the lumen of a cardiac chamber, the coronary sinus or superior vena cava, or a pulmonary artery or pulmonary vein close to the heart. Congenital fistulous connections between the coronary system and a cardiac chamber appear to represent persistence of embryonic intratrabecular spaces and sinusoids. They are the most common congenital coronary anomalies affecting hemodynamic parameters.CAF arises from the right coronary artery (RCA) in approximately 50% of patients, the left coronary artery (LCA) in approximately 42% of patients, and both the RCA and LCA in approximately 5% of patients. The majority of symptomatic CAFs originate from the RCA, but asymptomatic CAFs demonstrate a greater prevalence of origin from the LCA. More than 90% of the fistulas drain into the venous circulation. Low-pressure structures are the most common sites of drainage of the CAF. The most common drainage sites in order of decreasing frequency are the right ventricle (41%), right atrium (26%), pulmonary artery (17%), coronary sinus (7%), left atrium (5%), left ventricle (3%), and superior vena cava (1%).
Tortuous RCA with a fistula to the coronary sinus, abnormal origin of LCX, SVC drainage to left atrium
1. Zenooz N. et al. Coronary Artery Fistulas: CT Findings. RadioGraphics 2001; 29: 781??789.
2. Pelech AN. Coronary artery fistula. http://www.emedicine.com/ped/topic2505.htm. Accessed August 07, 2011.