Further Observations on the Use of Pacemakers in Patients with Postural Orthostatic Tachycardia Syndrome with Demonstrated Asystole.

A subgroup of postural orthostatic tachycardia syndrome (POTS) patients may also have features of neurocardiogenic syncope (NCS). Syncope and presyncope are predominant clinical features in this subgroup of patients. Asystole has been reported as the cause of some recurrent syncopal episodes following evaluation with an implantable loop recorder (ILR). We present our experience of pacing in a group of patients with POTS and NCS, which resulted in the complete elimination of syncope. We reviewed the charts of 500 patients at the University of Toledo Medical Center from 2003 to 2013 and identified 40 patients who were eligible for inclusion in this study. Patients were included in this study if they had clinical features of POTS and unusually frequent episodes of syncope. All study participants subsequently underwent ILR implantation. Forty patients, including 32 (80%) women, aged 33 ± 13 years were included in this study. All patients demonstrated prolonged asystole (> 6 seconds) or severe bradycardia (heart rate < 30 bpm) during their syncope. Ten patients demonstrated an asystole of more than 10 seconds and also had prolonged and convulsive syncope. All patients had abrupt syncope without any warning signs. All 40 patients underwent dual-chamber pacemaker implantation. Syncope was eliminated in all 40 patients following pacemaker implantation; however, they continued to experience orthostatic tachycardia. Our findings support that dual-chamber pacing may help to eliminate syncope in a subgroup of POTS patients with recurrent syncope and prolonged asystole on ILR.