Myocardial infarction and sinus node dysfunction as late complications after patch closure of the coronary arteriovenous fistula

Background. A coronary arteriovenous fistula is an uncommon cardiac anomaly. The fistula is frequently small with insignificant shunt. Surgical closure is generally recommended for patients with this condition when it is symptomatic. The mortality and morbidity of surgical closure is quite low. Methods and Results. A 63-year-old man developed acute posterolateral myocardial infarction, severe mitral regurgitation, and severe sinus node dysfunction two to three years after ligation of the drainage outlet of a large coronary arteriovenous fistula originating from the left circumflex artery and draining into the right atrium. Conclusions. It was postulated that, after patch closure of the fistulous outlet, a progressive retrograde thrombus formation inside the fistulous vessel, eventually involving the orifice of the left circumflex artery was responsible for these late events. Coronary bypass surgery of the related vessel is advised for such a type of surgical intervention.