Intrarater reliability of different methods of heart rate variability threshold analysis and postexercise parasympathetic reactivation in young women

Leonardo Pereira,Carlos Janssen Gomes da Cruz,Adriano Drummond,Rafaello Pinheiro Mazzoccante,Bruno Guilhen Ribeiro,Lúcia Kobayashi,Raiane Maiara dos Santos Pereira,Guilherme Eckhardt Molina

doi:10.1590/s1980-657420210003921

Abstract

Abstract Objective: To evaluate the reliability of HRVT and postexercise parasympathetic reactivation analysis after a submaximal exercise test in young women. Methods: Twenty-four young women [21.1 (20.1, 24.7) years; 21.4 (20.1, 23.1) kg/m2] underwent three incremental exercise tests on a treadmill on occasions separated by 48 h. R-R intervals were continuously recorded during the incremental tests and throughout 5 min of post-exercise active recovery for HRVT and parasympathetic reactivation analysis, respectively. HRVT was identified using two methods: a) the intensity where no significant reduction of SD1 HRV index was identified by visual inspection of the graphic (HRVTvisual), b) the first stage to present SD1 value < 3ms (HRVT3ms). Postexercise parasympathetic reactivation was assessed at each minute during five minutes of recovery using SD1 and r-MSSD indexes. Absolute and relative reliability were assessed using the coefficient of variation (CV) and the intraclass correlation coefficient (ICC), respectively. Results: Good (ICC = 0.81, CV = 17.3) and excellent (ICC = 0.90, CV = 4.6) reliability were observed for HRVT3ms and HRVTvisual, respectively. On the postexercise period, good reliability was observed for both SD1 (ICC = 0.82-89, CV = 22.1-28.9) and r-MSSD (ICC = 0.82-89, CV = 21.1-28.6), with a high correlation between indexes in all-time points of analysis (r = 0.96-0.99). Conclusions: HRVT may be reproducibly assessed in women, mainly when HRVTvisual is used for analysis. In addition, SD1 and r-MSSD provide reliable and redundant measures of postexercise parasympathetic reactivation.

Highlights

Heart rate variability (HRV) consists of the temporal oscillations between successive heartbeats, defined by the distance between two R waves (R-R interval- iRR)[1]
Considering the aforementioned questions, this study aimed to evaluate the reliability of different methods of Heart rate variability threshold” (HRVT) and postexercise parasympathetic reactivation analysis after a submaximal exercise test in young women
No differences between trials were identified for the load corresponding to HRVTvisual (p = 0.92) and HRVT3ms (p = 0.37), Loadpeak (p = 0.72) HRpeak (p = 0.61), or for any measure of parasympathetic reactivation [r-MSSD1 to r-MSSD5 (p = 0.11-0.51), SD11 to SD15 (p = 0.11 to 0.19)] during active recovery phase (Table 2)

Summary

Introduction

Heart rate variability (HRV) consists of the temporal oscillations between successive heartbeats, defined by the distance between two R waves (R-R interval- iRR)[1]. As previously demonstrated by the pharmacological blockade, HRV reflects primarily the autonomic activity on the sinus node, emerging as a valid and noninvasive method for cardiac autonomic assessment at resting condition, during a dynamic exercise, or in the post-exercise recovery phase[2,3,4]. The point of the incremental exercise test where the HRV is stabilized is commonly called “Heart rate variability threshold” (HRVT) and emerges as a practical alternative to anaerobic threshold determination[6,7,8,9]. Post-exercise recovery is characterized by a progressive increase in the root mean square of successive differences between the adjacent normal R-R intervals (r-MSSD) due to cardiac parasympathetic reactivation[2]. In a clinical and experimental setting, the cardiac parasympathetic reactivation is considered an independent predictor for cardiovascular prognostic and is often used to evaluate the effects of different pharmacological and non-pharmacological interventions on the cardiac autonomic nervous system[10,11,12]

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