Estudo do comportamento autonômico cardíaco e do acoplamento cardiorrespiratório em pacientes portadores da Síndrome da Apnéia Obstrutiva do Sono: efeitos da obesidade e do envelhecimento

The thesis consisted of three studies described below. The Study I, entitled: Is there a chronic sleep stage-dependent linear and nonlinear cardiac autonomic impairment in obstructive sleep apnea? The aim of this study was to perform HRV analysis in apneafree samples as well as during stage 2 and rapid eye movement (REM) sleep in mild and moderate OSA (MiOSA andMOSA,respectively) subjects as well as health controls (NonOSA). Methods This study included 20 MiOSA (37±14 years), 20 MOSA (39±8 years), and 18 NonOSA (36±8 years) subjects. Subjects underwent in-laboratory overnight polysomnography with electrocardiography recording. HRV indices were obtained by analyzing the R R intervals (RRi) in 5-min apnea-free samples by the linear frequency domain [low frequency (LF), high frequency (HF) and LF/HF], Poincaré plot [standard deviation (SD1) and (SD2)], recurrence plot [mean line length (Lmean)], recurrence rate (REC), determinism (DET), and Shannon entropy (ShanEn). The MOSA group presented with higher LF, LF/HF and DET indices compared to NonOSA as well as a lower parasympathetic index (HF), suggesting sympathetic hyperactivity in MOSA subjects. Interestingly, MiOSA subjects failed to show the expected linear HRV difference between sleep stages, as observed in NonOSA, which may represent an early onset of autonomic impairment at this stage of OSA. In OSA patients, there is a chronic sleep stage dependent impairment of linear and nonlinear cardiac autonomic modulation. Interestingly, this impairment may be identifiable during the early stages of the disease. The Study II, entitled: Heart Rate Variability and Cardio-Respiratory Coupling during sleep in Patients prior to Bariatric Surgery The aim of this study was to determine the relationship among severity of obesity, autonomic cardiac regulation, respiratory variations, and cardio-respiratory coupling during different sleep stages (SS), using spectral analysis of HRV and respiration variability (RS) signals in patients pre-operative BS. 29 consecutive ...