A case of an atrial tachycardia originating from an occluded coronary sinus ostium with a persistent left superior vena cava

We present a case of a 37-year-old female who complained of frequent palpitations caused by an atrial tachycardia and atrial premature contractions. Angiography revealed that the coronary sinus was occluded at the ostium and connected to a persistent left superior vena cava. An electrophysiological study and three-dimensional mapping revealed that the origin of the atrial tachycardia and atrial premature contractions was at the coronary sinus ostium in the right atrium. After repeat applications of radiofrequency energy at that site, no further atrial tachycardia or atrial premature contractions were induced by atrial burst pacing. To the best of our knowledge, this is the first report of an atrial tachycardia originating from an occluded coronary sinus ostium.