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. 2017 Apr;139(4):e20163189.
doi: 10.1542/peds.2016-3189.

Postural Heart Rate Changes in Young Patients With Vasovagal Syncope

Marvin S Medow  1   2 , Sana Merchant  3 , Melissa Suggs  3 , Courtney Terilli  3 , Breige O'Donnell-Smith  3 , Julian M Stewart  3   2
Affiliations

Postural Heart Rate Changes in Young Patients With Vasovagal Syncope

Marvin S Medow et al. Pediatrics. 2017 Apr.

Abstract

Background and objectives: Recurrent postural vasovagal syncope (VVS) is caused by transient cerebral hypoperfusion from episodic hypotension and bradycardia; diagnosis is made by medical history. VVS contrasts with postural tachycardia syndrome (POTS), defined by chronic daily symptoms of orthostatic intolerance with excessive upright tachycardia without hypotension. POTS has recently been conflated with VVS when excessive tachycardia is succeeded by hypotension during tilt testing. We hypothesize that excessive tachycardia preceding hypotension and bradycardia is part of the vasovagal response during tilt testing of patients with VVS.

Methods: We prospectively performed head-up tilt (HUT) testing on patients with recurrent VVS (n = 47, 17.9 ± 1.1 y), who fainted at least 3 times within the last year, and control subjects (n = 15, 17.1 ± 1.0 y), from age and BMI-matched volunteers and measured blood pressure, heart rate (HR), cardiac output, total peripheral resistance, and end tidal carbon dioxide.

Results: Baseline parameters were the same in both groups. HR (supine versus 5 and 10 minutes HUT) significantly increased in control (65 ± 2.6 vs 83 ± 3.6 vs 85 ± 3.7, P < .001) and patients with VVS (69 ± 1.6 vs 103 ± 2.3 vs 109 ± 2.4, P < .001). HUT in controls maximally increased HR by 20.3 ± 2.9 beats per minute; the increase in patients with VVS of 39.8 ± 2.1 beats per minute was significantly greater (P < .001). An increase in HR of ≥40 beats per minute by 5 and 10 minutes or before faint with HUT, occurred in 26% and 44% of patients with VVS, respectively, but not in controls.

Conclusions: Orthostasis in VVS is accompanied by large increases in HR that should not be construed as POTS.

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Conflict of interest statement

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

Figures

FIGURE 1
FIGURE 1
A scatterplot of the time to near faint in patients with VVS. The average time to near faint formula image for all 47 patients was 10 minutes, 40 seconds.
FIGURE 2
FIGURE 2
The change in HR (in beats per minute) measured in each control subject (Ο) and patients with VVS (●) at 5 minutes and 10 minutes after imposition of an HUT.
FIGURE 3
FIGURE 3
Changes in HR (in beats per minute) binned, at 5 minutes (upper panel) and 10 minutes (lower panel) after the imposition of an HUT. HR changes are depicted as their relative frequency (%) of occurrence.
See this image and copyright information in PMC

Comment in

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