Quadruple atrioventricular nodal pathways: involved in orthodromic atrioventricular reentrant tachycardia.

Supraventricular tachycardia can be caused by multiple atrioventricular nodal pathways or atrioventricular accessory pathways. Herein, we report the case of a patient who was diagnosed with an orthodromic atrioventricular reentrant tachycardia that was caused by an unusual combination of quadruple atrioventricular nodal pathways and an atrioventricular accessory pathway. Radiofrequency catheter ablation of the accessory pathway successfully eliminated the arrhythmias and the patient's symptoms. Careful analysis of complete electrophysiologic studies can help in the diagnosis of such rare clinical presentations.