HEART RATE VARIABILITY IN WOMEN WITH DIFFERENT PHENOTYPES OF ARTERIAL HYPERTENSION: A COMPARATIVE ANALYSIS

Objective: Different phenotypes of hypertension may present distinct patterns of autonomic regulation, but the influence of these patterns on treatment refractoriness remains unclear. Given that heart rate variability (HRV) can reveal important functional alterations, especially when combining linear and nonlinear metrics, the present study aims to evaluate HRV parameters in women diagnosed with arterial hypertension using both linear and nonlinear methods. Design and method: This study included 49 women aged 49 to 82 years, monitored at an Arterial Hypertension Outpatient Clinic. Participants were divided into three groups: Hypertensive (HTN, n=13), Resistant Hypertension (RHTN, n=21), and Refractory Hypertension (RefHTN, n=15). Autonomic function was assessed through spontaneous variability analysis of a series of RR intervals using a Polar® heart rate monitor for ECG signal acquisition and the Kubios® software for data processing. Descriptive analysis and one-way ANOVA were performed, considering p<0.05. Results: Spectral components of HRV showed no statistically significant differences among groups. Mean LF values were 118.9 ± 70.8 ms2(HTN), 195.0 ± 179.7 ms2(RHTN), and 130.3 ± 142.0 ms2(RefHTN) (p=0.3160). Mean HF values were 91.8 ± 62.8 ms2(HTN), 151.1 ± 189.2 ms2(RHTN), and 112.9 ± 133.5 ms2(RefHTN) (p=0.5658). The VLF component also showed no significant difference (p=0.7479). The LF/HF ratio had mean values of 1.8 ± 0.9 (HTN), 2.2 ± 1.9 (RHTN), and 1.9 ± 2.2 (RefHTN) (p=0.6995). Stress index values were 19.1 ± 6.0 (HTN), 17.2 ± 6.5 (RHTN), and 18.4 ± 6.8 (RefHTN) (p=0.6995). For the parasympathetic index (PNS), the observed means were -0.8 ± 0.8 (HTN), -0.9 ± 0.7 (RHTN), and -0.4 ± 1.0 (RefHTN) (p=0.2329). The sympathetic index (SNS) values were 1.8 ± 1.4 (HTN), 1.6 ± 1.3 (RHTN), and 1.3 ± 1.7 (RefHTN) (p=0.7237). Entropy analysis revealed mean values of 1.5 ± 0.1 (HTN), 1.4 ± 0.1 (RHTN), and 1.5 ± 0.1 (RefHTN) (p=0.0505).Conclusions: No statistically significant differences were observed among the groups, indicating that autonomic behavior is not a determinant factor in the clinical presentation of hypertension in terms of refractoriness. These findings suggest that other pathophysiological mechanisms may be involved.