Occlusion of a congenital right coronary–to–vena cava superior fistula induces temporary junctional bradycardia and atrial fibrillation

Introduction The finding of a congenital right coronary–to–vena cava superior (RCVCS) fistula is extremely rare. The overall prevalence of coronary artery fistulae is 0.02%–0.9%, of which the coronary-to–pulmonary artery fistula is the most common type (78%) and the coronary-to–vena cava superior fistula the least common (1.8%). Symptoms such as dizziness, palpitations, angina, reduced exercise capacity, and/or fatigue may accompany this phenomenon, but most coronary fistulae are asymptomatic. Patients who developed secondary pulmonary hypertension owing to left-to-right shunting via the arteriovenous fistula will likely be symptomatic, as illustrated in this case report, whereas in normal-pressure fistulas symptoms are less frequent. Therapeutic occlusion of the fistula is, certainly in the case of symptoms, recommended, since an increased risk exists for endocarditis, transient ischemic attacks, coronary steal phenomenon, pericardial tamponade, myocardial ischemia, and even hydrops fetalis when left untreated. Various treatment strategies are described, varying from cardiothoracic surgery to minimal invasive occlusion by using devices like Amplatzer plugs and Gianturco coils. Owing to its rarity, tailor-made therapy differs per center and depends on available expertise. Interestingly, to our knowledge this is the first case report describing the relation of closing the fistula and triggering of arrhythmia, and raises the question of a potential relation between paroxysmal atrial fibrillation (AF) and a coronary fistula.