Skin Sympathetic Nerve Activity and the Short-Term QT Interval Variability in Patients With Electrical Storm.

Songwen Chen,Guannan Meng,Xiaochun Li,Johnson Wong,Thomas H Everett Iv,Anisiia Doytchinova,Julie Lacy,Peng-Sheng Chen,Susan Straka

doi:10.3389/fphys.2021.742844

Abstract

Background: Skin sympathetic nerve activity (SKNA) and QT interval variability are known to be associated with ventricular arrhythmias. However, the relationship between the two remains unclear.Objective: The aim was to test the hypothesis that SKNA bursts are associated with greater short-term variability of the QT interval (STVQT) in patients with electrical storm (ES) or coronary heart disease without arrhythmias (CHD) than in healthy volunteers (HV).Methods: We simultaneously recorded the ECG and SKNA during sinus rhythm in patients with ES (N = 10) and CHD (N = 8) and during cold-water pressor test in HV (N = 12). The QT and QTc intervals were manually marked and calculated within the ECG. The STVQT was calculated and compared to episodes of SKNA burst and non-bursting activity.Results: The SKNA burst threshold for ES and HV was 1.06 ± 1.07 and 1.88 ± 1.09 μV, respectively (p = 0.011). During SKNA baseline and burst, the QT/QTc intervals and STVQT for ES and CHD were significantly higher than those of the HV. In all subjects, SKNA bursts were associated with an increased STVQT (from 6.43 ± 2.99 to 9.40 ± 5.12 ms, p = 0.002 for ES; from 9.48 ± 4.40 to 12.8 ± 5.26 ms, p = 0.016 for CHD; and from 3.81 ± 0.73 to 4.49 ± 1.24 ms, p = 0.016 for HV). The magnitude of increased STVQT in ES (3.33 ± 3.06 ms) and CHD (3.34 ± 2.34 ms) was both higher than that of the HV (0.68 ± 0.84 ms, p = 0.047 and p = 0.020).Conclusion: Compared to non-bursting activity, SKNA bursts were associated with a larger increase in the QTc interval and STVQT in patients with heart disease than in HV.

Highlights

Sudden cardiac death (SCD) affects over 300,000 people a year in the USA (Myerburg et al, 1997)
SKNA bursts were associated with an increased short-term variability of the QT interval (STVQT)
Compared to non-bursting activity, SKNA bursts were associated with a larger increase in the QTc interval and STVQT in patients with heart disease than in healthy volunteers (HV)

Summary

Introduction

Sudden cardiac death (SCD) affects over 300,000 people a year in the USA (Myerburg et al, 1997). We have developed a new method (neuECG) to simultaneously record the ECG and sympathetic nerve activity from the skin by recording signals from ECG electrodes at a high sampling rate and a wide frequency bandwidth (Everett et al, 2017; Kabir et al, 2017; Shen et al, 2017; Uradu et al, 2017; Kusayama et al, 2019). These signals can be differentially filtered to display both ECG (0.5–150 Hz) and skin sympathetic nerve activity (SKNA, 500–1,000 Hz).

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Discussion

Conclusion