The complexity of hemodynamic response to the tilt test with and without nitroglycerine provocation in patients with vasovagal syncope

Katarzyna Buszko,Agnieszka Piątkowska,Grzegorz Opolski,Tomasz Fabiszak,Edward Koźluk

doi:10.1038/s41598-018-32718-2

Katarzyna Buszko, Agnieszka Piątkowska + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-32718-2

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Abstract

The paper presents a comparison of vasovagal syndrome occurrence in a head up tilt table test between patients with a positive result of passive tilt test and those with a positive result after pharmacological provocation. The study group consisted of 80 patients: 57 patients who experienced syncope in the passive phase of the test (43 women (aged: 35.6 ± 16.2) and 14 men (aged: 41.7 ± 15.6) and 23 patients who experienced syncope after pharmacological provocation (17 women (age: 32.3 ± 12) and 6 men (age: 43 ± 15). The main investigation was based on the assessment of monitored signals complexity: heart rate, blood pressure and stroke volume. The analysis of complexity in chosen measurement phases was performed with Sample Entropy. The investigation showed that the reactions of autonomic nervous system during tilt test and before syncope are similar for positive result of passive tilt test and positive result of tilt test with provocation. The differences in supine position occurred only in analysis based on impedance measurement (SV: p = 0.01). Significant differences were denoted for all signals just before the syncope (RRI, sBP, dBP: p = 0,00001 and SV: p = 0.01). In analysis of signals complexity the significant differences occurred just before the syncope for Sample Entropy of blood pressure (SampEn (sBP): p = 0.0008, SampEn (dBP): p = 0,0001).

Highlights

Syncope is a common cause of emergency visits and hospital admissions[1]
A typical diagnostic procedure in syncopal episodes is based on Head Up Tilt Test (HUTT) usually performed with Task Force Monitor (TFM) - a device commonly used for assessment of neuro-cardiogenic syncope[11,12,13]
Numerous investigations dealing with prediction of the final result of HUTT rely solely on the analysis of the basic signals such as RRI, systolic blood pressure (sBP), dBP in the supine position or a short-time response to tilt[51,52,53,54,55,56]

Summary

Introduction

Syncope is a common cause of emergency visits and hospital admissions[1]. Each syncope episode is an indication for a more in-depth diagnostic work-up. A typical diagnostic procedure in syncopal episodes is based on Head Up Tilt Test (HUTT) usually performed with Task Force Monitor (TFM) - a device commonly used for assessment of neuro-cardiogenic syncope[11,12,13]. The investigations focused on identification of differences in heart rhythm, blood pressure and impedance between patients with positive and negative HUTT test results. It would be more diagnostically useful to be able to predict occurrence of syncope based solely on the reaction to orthostatic stress, without the necessity of a long-term tilt For this reason, we focused our investigation on this aspect of syncope diagnosis. The most popular nonlinear methods are: Poincare plots, fractal methods, symbolic dynamics measures, heart rate asymmetry and entropy[16,17,19,20]

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