Acompanhamento longitudinal do sistema nervoso autônomo em diferentes espectros amostrais: uma análise baseada em dois estudos

Abstract

The autonomic nervous system (ANS) has the main function of homeostasis and the regulation of several physiological mechanisms of the body. The aim of this thesis consists of two longitudinal studies: a) Study 1: investigate the behavior of the heart rate (HR) at rest, the heart rate variability (HRV) and the cardiac vagal activity (CVA) in patients with type 1 diabetes mellitus (DM1); b) Study 2: investigate the behavior of resting HR and stroke in patients undergoing endoscopic thoracic sympathectomy surgery (STE). The first study with follow-up average of 114 days (80-185 days), in which 35 males aged 18 to 30 were divided into two groups: DM1G - 19 young people with type 1 diabetes mellitus, with disease exposure time of 13 ± 6.89 (mean ± standard deviation) years and GC - 16 healthy subjects. The two groups were submitted in two different times the evaluation of resting HR and HRV tests and four- second exercise test (T4s), which alone assesses the parasympathetic branch of the SNA, and its results expressed by the cardiac vagal index (CVI ). The indices of the time domain and the frequency obtained by the HRV showed no significant difference (p> 0.05), as well as the IVC (p = 0.33). However when we analyze the resting HR recorded during the HRV observed differences between DM1G and the CG (p = 0.0001). In the second study, we evaluated 22 patients (13 women) aged 22.5 ± 8.8 (mean ± SD) undergoing STE. The average resting HR was measured by electrocardiogram in leads (CC5 or CM5) 20 minutes before the T4s that was used to isolated assessment of cardiac vagal activity (CVA) at three time points: before surgery, one month and four years after surgery. The resting heart rate decreased significantly between the preoperative evaluation and one month after surgery (73.1 ± 1.6 versus 69.7 ± 1.2, respectively; p = 0.01; mean ± standard error ), tending after four years to return to pre-operative values (p = 0.31). In IVC we experienced significant reduction between the preoperative and one month after surgery (1.44 ± 0.04 versus 1.53 ± 0.03, respectively; p = 0.02; mean ± standard error of the mean), tending Also returning close to preoperative values after four years of surgery (p = 0.10). In the first study we found that with an average follow-up of 114 days were no differences in SNA expressed by HRV and CVI in individuals with DM1. However, the resting HR was higher in individuals with DM1. In the second study, the STE resulted in changes in resting HR and stroke one month after the surgery, returning after four years, to values close to the preoperative period