Efeito agudo da neuromodulação não invasiva na função cardiovascular, percepção subjetiva de esforço e capacidade funcional de pessoas com insuficiência cardíaca : ensaio clínico randomizado e controlado

Abstract

Introduction: Heart failure is a chronic condition associated with high rates of morbidity and mortality, significantly impacting the quality of life of affected individuals. High-definition transcranial direct current stimulation (HD-tDCS) has emerged as a promising neuromodulatory approach with potential influence on cardiovascular function. However, its effects on heart failure are still poorly understood. Objective: To evaluate the effects of HD-tDCS on cardiovascular function, subjective perception of effort and functional capacity of individuals with heart failure. Methods: A randomized clinical trial was conducted with individuals diagnosed with heart failure functional class II and III according to the New York Heart Association (NYHA). Participants underwent three 20-minute sessions of HD-tDCS (stimulation, inhibition and sham) applied to the left temporal and insular cortex at an intensity of 3 mA. After each session, a six-minute walk test was performed. The variables analyzed included heart rate variability through Holter monitoring, heart rate, distance covered in the 6-minute walk test, perceived exertion, blood pressure and partial oxygen saturation. The data were analyzed using the Shapiro-Wilk test and the Friedman test, given the non-normal distribution of the data. Results: There was a difference in the power of high-frequency heart rate variability in the cathodal current group (55.90 Hz) compared to the anodal (172 Hz) and sham (219 Hz) groups (p=0.003). In addition, the cathodal group had a lower heart rate (85 bpm) compared to the anodal (92 bpm) and sham (91 bpm) groups (p=0.045). The other variables did not show significant differences between the groups. Conclusion: The findings suggest that HD-tDCS can influence autonomic modulation, particularly in high-frequency heart rate variability and in the heart rate response to exercise, with faster recovery after physical exertion. Although no significant effects were observed in other physiological variables, the results indicate a therapeutic potential for the technique in autonomic regulation in heart failure. Additional studies are needed to better elucidate the underlying mechanisms and optimize stimulation parameters for future clinical applications.