Abstract 302: Negative Effects of Fludrocortisone Treatment in Adolescents with POTS and Syncope

Abstract

Fludrocortisone (Florinef) is commonly used to treat symptoms associated with postural orthostatic tachycardia syndrome (POTS). We have previously shown that Florinef treatment in children with POTS improved the changes in baroreflex sensitivity (BRS) and heart rate variability (HRV) measured as the root of mean square of successive differences (rMSSD) during upright tilt compared to untreated children with POTS. We noticed that a subgroup of our patients experienced POTS symptoms followed by syncope at later time points during the 45 min tilt test in both Florinef treated and untreated groups. We stratified based on syncope and compared the effect of Florinef treatment on both groups. Of the 32 POTS patients studied (15.0 ± 0.6 yrs old), 14 were treated with Florinef of whom 5 had syncope, and 18 were untreated of whom 5 had syncope. In the non-syncopal group, subjects treated with Florinef for a minimum of 4 wks compared with untreated POTS without syncope had similar baseline supine measures of MAP, HR, BRS and HRV before tilt, and less reduction in BRS during tilt measured as Seq UP (-7.1 ± 2.5 vs -15.1 ± 3.5 ms/mmHg; p<0.03), a trend for less attenuation in HRV (-22.4 ± 6.4 vs -35.3 ± 6.3 ms; p<0.07) and reduced tachycardia with tilt (25 ± 6 vs 38 ± 4 beats/min; p<0.02) compared with the untreated group. Meanwhile, in the syncopal group, Florinef-treated patients at baseline in the supine position before tilt had worse BRS function measured as Seq UP compared to untreated (11.9 ± 2.2 vs 26.0 ± 6.7 ms/mm Hg; p<0.04), a tendency for lower HRV (40.8 ± 7 vs 61.2 ± 12 ms; p<0.08) and higher HR (82 ± 3 vs 65 ± 7 beats/min; p<0.02) than untreated POTS patients with syncope. In contrast to non-syncopal POTS, the HR increase during tilt in syncopal POTS subjects was not reduced by the Florinef. The impairments in baseline supine autonomic function in POTS with syncope patients treated with Florinef relative to untreated patients and lack of improvement in the performance upon upright tilt suggests that POTS patients should be stratified by syncope status during the tilt test prior to assigning this treatment regimen. Additional studies are needed to better define these patients and to determine if other pharmacologic agents would provide a more optimal treatment. Support: AHA12CRP9420029