Anodal transcranial direct current stimulation associated with aerobic exercise on the functional and physical capacity of patients with heart failure with reduced ejection fraction: ELETRIC study protocol.

BACKGROUND: The hallmark symptom of heart failure (HF) is severe exercise intolerance. Fortunately, accumulated evidence suggests that exercise programs improve physical performance, enhance autonomy in daily activities and quality of life, and reduce cardiovascular and other hospitalizations. Recently, experimental studies have explored the application of non-invasive brain stimulation techniques, especially transcranial direct current stimulation (tDCS), aiming to improve physical performance due to its ability to modulate brain functioning. The primary objective of the present study is to evaluate the effects of anodal tDCS associated with aerobic exercise on the functional capacity of patients with HF with reduced ejection fraction (HFrEF). Secondary objectives are to compare the effects of tDCS associated with aerobic exercise vs. sham-tDCS associated with aerobic exercise on cardiopulmonary exercise capacity; inflammatory cytokines; and quality of life. METHODS: This is a two-arm, prospectively registered, randomized trial with concealed allocation, double-blind, and intention-to-treat analysis. Forty-four patients with HFrEF will be recruited. The experimental group will undertake 25-30 min aerobic exercise training associated with tDCS, for 4 weeks. The control group will undergo the same aerobic exercise training, but with sham-tDCS. The primary outcome will be functional performance by the 6-min walk test. Secondary outcomes will include cardiopulmonary exercise capacity, inflammatory cytokines, and quality of life. Outcomes will be collected by a researcher blinded to group allocation at baseline (T0) and after 4 weeks of intervention (T1). DISCUSSION: Although previous studies have investigated the combined effect of tDCS on T3 area and physical performance and have suggested that tDCS could have reduced ratings of perceived exertion by affecting the activity of the insular cortex, and therefore increase exercise tolerance, this study is the first to evaluate the effects of the addition of anodal tDCS to aerobic exercise training for improving physical and functional performance, decreasing the perceived exertion, altering the quantification of inflammatory cytokines, and improving the subclinical values of the cardiopulmonary test in patients with HFrEF, which could result in an important advance in cardiac rehabilitation for patients with chronic HF. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (ReBEC) RBR-10w787j6. Registered on 25 April 2023. https://ensaiosclinicos.gov.br/pesquisador.

Autonomic control of heart rate during non-linear incremental upper-limb resistance exercise with elastic bands in young healthy female subjects.

BACKGROUND: Elastic bands are therapeutic tools widely used in rehabilitation. However, knowledge regarding autonomic cardiovascular overload during this type of resistance exercise is limited. This study assessed the autonomic control of heart rate during an incremental exercise protocol with elastic bands in sedentary healthy young individuals. METHODS: Ten young women were subjected to an exercise protocol involving bilateral shoulder flexion to 90° with various thicknesses of elastic bands; the exercise was performed for 36 uninterrupted repetitions with a 15-minute rest interval between sets. During the exercise, the RR intervals (R-Ri) were collected and determined, the heart rate variability was analyzed. RESULTS: All subjects completed the exercise protocol. Heart rate increased, and RR intervals decreased from the yellow elastic band onward. However, the square root of the sum of the square of the difference of RR intervals divided by the number of RR interval, standard deviation of the arithmetic mean of all normal RR intervals, and standard deviation of the RR interval instantaneous intervals of type I decreased significantly when performed with the green band onward (P<0.05). CONCLUSIONS: Exercise with progressive elastic load increases heart rate. However, the green elastic band induces less total and parasympathetic modulation heart rate variability.