Intra-atrial and atrioventricular nodal reentrant tachycardia in the same subject diagnosed at transesophageal electrophysiologic study.

The case report deals with a young woman with frequent episodes of paroxysmal narrow QRS tachycardia of uncertain etiology at Holter monitoring in whom a transesophageal electrophysiologic study was carried out in order to identify the electrogenetic mechanism of the presenting arrhythmia. During the electrophysiologic study, 2 different types of supraventricular tachycardia were induced and diagnosed as intra-atrial and atrioventricular nodal reentrant tachycardia. This association represents a rare finding and can provide a possible explanation to the intriguing electrocardiographic pattern observed at Holter monitoring. Therefore, transesophageal electrophysiologic study proved to be a valuable method for evaluating subjects with complex supraventricular tachycardias.