Dados do Trabalho

Título

HEART RATE VARIABILITY IN OBSTRUCTIVE SLEEP APNEA PATIENTS SUBMITTED TO ONE BOUT OF INSPIRATORY MUSCLE TRAINING

Introdução

The inspiratory muscle training (IMT) is emerging as an alternative adjunct treatment for obstructive sleep apnea (OSA) improving apnea hypopnea index, sleep quality and excessive daytime sleepiness. The IMT is a home-based program, with previous orientation by the physiotherapist, but unsupervised in the execution of the exercise training. However, the acute responses of the cardiovascular system autonomic control to such exercise in OSA subjects remains unclear.

Objetivo

To determine the immediate and late acute responses of the cardiac autonomic balance in patients with OSA submitted to IMT.

Métodos

20 OSA subjects of both genders (52,15 ± 11,00 years old) were randomized to a) experimental group (n =10) who performed IMT (powerbreathe®classiclight) with a load of 70% of the maximal inspiratory pressure (MIP), three sets of 30 respiratory incursions each and resting 1 minute between sets and b) control group (n=10), carried out the same protocol, but with no load. The cardiovascular autonomic balance was assessed by the heart rate variability (HRV). The heart rate was continually registered (Polar RS 800Cx) at rest (10 min), immediately after (10min) and 1h after the IMT session (10 min). Then, the RR interval generates a tachogram that was analyzed in the frequency domain by Kubios HRV Analysis Software and decomposed into low (LF: 0.04–0.15 Hz) and high (HF: 0.15–0.4 Hz) frequency bands and the ratio HF/LF. HRV at rest, immediately after and 1h and after the IMT was compared using two-way, repeated-measures ANOVA

Resultados

Comparing the LF values, there were no inter (p= 0,946) or even intragroup (experimental group; p= 0,835/control group; p= 0,670) differences. Regarding to the HF analyses, there were also no inter (p=0,94) or intragroup (at the experimental group; p= 0,845/control group; p= 0,667) differences. The ratio LF/HF also had no inter (p= 0,797) or intragroup (experimental group; p =0,455/ control group; p = 0.818) differences.

Conclusões

The HRV analyzes showed no inter and intragroup differences related to the LF and HF components of and to the HF/LF ratio, showing discreet changes in the autonomic cardiac modulation in response to one single session of IMT. Therefore, home-based IMT without supervision can be considered as a safe and viable training modality for patients with OSA.

Palavras-chave

inspiratory muscle training; acute responses; heart rate variability; obstructive sleep apnea