Effects of slow breathing rate on heart rate variability and arterial baroreflex sensitivity in essential hypertension

Abstract

This study is to investigate the effects of slow breathing on heart rate variability (HRV) and arterial baroreflex sensitivity in essential hypertension.We studied 60 patients with essential hypertension and 60 healthy controls. All subjects underwent controlled breathing at 8 and 16 breaths per minute. Electrocardiogram, respiratory, and blood pressure signals were recorded simultaneously. We studied effects of slow breathing on heart rate, blood pressure and respiratory peak, high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio of HRV with traditional and corrected spectral analysis. Besides, we tested whether slow breathing was capable of modifying baroreflex sensitivity in hypertensive subjects.Slow breathing, compared with 16 breaths per minute, decreased the heart rate and blood pressure (all P < .05), and shifted respiratory peak toward left (P < .05). Compared to 16 breaths/minute, traditional spectral analysis showed increased LF power and LF/HF ratio, decreased HF power of HRV at 8 breaths per minute (P < .05). As breathing rate decreased, corrected spectral analysis showed increased HF power, decreased LF power, LF/HF ratio of HRV (P < .05). Compared to controls, resting baroreflex sensitivity decreased in hypertensive subjects. Slow breathing increased baroreflex sensitivity in hypertensive subjects (from 59.48 ± 6.39 to 78.93 ± 5.04 ms/mm Hg, P < .05) and controls (from 88.49 ± 6.01 to 112.91 ± 7.29 ms/mm Hg, P < .05).Slow breathing can increase HF power and decrease LF power and LF/HF ratio in essential hypertension. Besides, slow breathing increased baroreflex sensitivity in hypertensive subjects. These demonstrate slow breathing is indeed capable of shifting sympatho-vagal balance toward vagal activities and increasing baroreflex sensitivity, suggesting a safe, therapeutic approach for essential hypertension.

Metabolic syndrome is associated with decreased heart rate variability in a sex‐dependent manner: a comparison between 252 men and 249 women

“…Furthermore, mechanical factors that occur during respiration (stretch of the atria that results from changes in thoracic pressure and cardiac filling) influence HRV independent of changes in cardiac autonomic nerve activity (Billman, 2013b). Several studies have shown that slow, paced breathing strengthens vagal activity and modifies HRV (Howorka et al, 2013;Prinsloo et al, 2013;Kromenacker et al, 2018;Li et al, 2018). In the current study, the influence of breathing on the HRV indices was taken into account by adjusting the results for breathing frequency.…”

Assessment of Diabetic Autonomic Nervous Dysfunction with a Novel Percussion Entropy Approach

“…Previous studies have demonstrated that diabetes is associated with suppressed autonomic activities and blunted baroreflex [19,39]. Previous studies have demonstrated the use of frequency domain [17][18][19] and time domain [20,23] parameters in noninvasively assessing autonomic nervous function in diabetic patients but their sensitivities remain unclear. Taking into account the fact that baroreflex sensitivity is an indicator of autonomic function [15] as well as previous findings showing a good correlation between DVP signals and real-time changes in blood pressure [26][27][28], the current study investigated the possibility of assessing autonomic sensitivity through quantifying the matches between the two time series of DVP and RRI with a shift number of 1 to 5 based on the finding of a previous report that showed a delay of BRS between one to five heartbeats [16].…”

“…For instance, frequency domain analysis of heart rate variability (HRV) based on R-R intervals (RRI) from electrocardiograph (EKG) is an assessment method for autonomic nervous activity and baroreflex sensitivity [14]. The parameter of low-to highfrequency power ratio (LFP/HFP, LHR) thus obtained is considered to reflect the relative activities of the sympathetic and parasympathetic nervous systems [17][18][19]. However, such a frequency domain parameter has its limitations because of the nonstationary and nonlinear nature of the physiological signals to be analyzed [20][21][22].…”

“…Each subject was required to refrain from theophylline-containing medications and caffeine-containing beverages for at least 8 hours before acquisition of data. Before taking the tests, all subjects were requested to sign informed consent and complete questionnaires on demographics and medical histories as well as Complexity 3 [17][18][19] and time [20,23] domains to obtain the low-to high-frequency power ratio (LFP/HFP, LHR) and Poincaré index (SD1/SD2 ratio, SSR), respectively. Percussion entropy index (PEI) was computed from the synchronized Amp and RRI time series for each testing subject.…”

Effect of slow breathing exercise on non linear Heart rate variability in transfusion dependent thalassemic patients

“…SBE has important role on autonomic balance by increasing parasympathetic activity and decreasing sympathetic activity 18 . This exercise improves CANF by increasing parasympathetic activity or decreasing sympathetic activity in some diseases and also in normal healthy person [19][20] .Though several studies investigated effect of SBE on autonomic function in other diseases but there is no published report investigating the effect of SBE on nonlinear measures of HRV in TDT patients. Therefore this study aimed to evaluate the effect of SBE on nonlinear measures(poincaré plot) of HRV in TDT patients so that SBE can be used as an adjunct to conventional treatment and improve CANF as well as reduce the risk of cardiovascular complications.…”