New onset postural orthostatic tachycardia syndrome following ablation of AV node reentrant tachycardia.

BACKGROUND: Autonomic dysfunction presenting as inappropriate sinus tachycardia has been reported to occur following slow pathway ablation for atrioventricular node tachycardia. We report on a series of patients who developed new onset postural orthostatic tachycardia syndrome (POTS) following successful radiofrequency ablation of atrioventricular nodal reentrant tachycardia (AVNRT).
METHODS: The study was a retrospective analysis that was approved by our Institutional Review Board. Patients were identified from those seen at our Syncope and Autonomic Disorders Clinic. A total of six patients were identified who were previously healthy except for supraventricular tachycardia. Each was found to have AVNRT during electrophysiology study and each underwent successful radiofrequency modification of the slow atrioventricular nodal pathway. Following ablation each patient developed the new onset of symptoms of orthostatic intolerance consistent with POTS.
RESULTS: After an initial symptom-free period (3-6 weeks) post ablation each patient began to experience symptoms of orthostatic intolerance. All six patients began to experience progressive severe fatigue. Orthostatic tachycardia was reported by five patients, syncope by three patients, and presyncope by all six patients. Each patient reported the occurrence of symptom while upright that were relieved by becoming supine. Each patient had experienced symptoms for greater than 6 months prior to being seen at our center. Three patients reported such severe symptoms of orthostatic tachycardia that they underwent repeat electrophysiology study; however, none had evidence of AVNRT. Each patient demonstrated a POTS response within the first 10 min of upright tilt with reproduction of their clinical symptoms that had occurred post ablation.
CONCLUSION: POTS may be a complication of radiofrequency ablation of AVNRT.