Massive congenital coronary arteriovenous malformation presenting with exertional dyspnea and desaturation in an adult: a case report and review of the literature.

A coronary arteriovenous fistula is a congenital or acquired coronary artery anomaly in which blood is shunted into a cardiac chamber, great vessel or other structure, superceding the myocardial capillary network. The clinical presentation may be heralded by the development of dyspnea, congestive heart failure, angina, endocarditis, dysrhythmias or myocardial infarction. The authors describe a left to right coronary artery to coronary sinus shunt that produced an elevation in right atrial pressure during exercise and thereby opened a patent foramen ovale and manifested as exercise-induced desaturation. Although noninvasive imaging may facilitate the diagnosis and identification of the origin and insertion of coronary arteriovenous fistulae, cardiac catheterization is necessary for the precise delineation of coronary anatomy, and to show the presence of concomitant atherosclerosis and structural anomalies. Possible therapeutic options in the management of coronary arteriovenous malformations include transcatheter embolization, surgical correction or expectant management.