Neuromuscular electrical stimulation but not photobiomodulation therapy improves cardiovascular parameters of rats with heart failure.

The aim was to analyze the effect of neuromuscular electrical stimulation (NMES) and photobiomodulation (PBMT) on cardiovascular parameters, hemodynamic function, arterial baroreflex sensitivity (BRS), and autonomic balance (ANS) of rats with heart failure (HF). Male Wistar rats (220-290g) were organized into five groups: Sham (n=6), Control-HF (n=5), NMES-HF (n=6), PBMT-HF (n=6), and NMES+PBMT-HF (n=6). Myocardial infarction (MI) was induced by left coronary artery ligation. Animals were subjected to an eight-week NMES and PBMT protocol. Statistical analysis with the General Linear Model (GLM) followed by the Bonferroni post hoc test. Rats of NMES-HF group showed a higher MI area than Control-HF group (P=0.003), PBMT-HF (P=0.002), and NMES+PBMT-HF (P=0.012). NMES-HF and NMES+PBMT-HF showed higher pulmonary congestion (P=0.004 and P=0.02), and lower systolic pressure (P=0.019 and P=0.002) than Sham group. NMES+PBMT-HF showed lower mean arterial pressure (P=0.02) than Sham group. Control-HF showed a higher heart rate than NMES-HF and NMES+PBMT-HF (P=0.017 and P=0.013). There was no difference in the BRS and ANS variables between groups. In conclusion, eight-week NMES isolated or associated with PBMT protocol reduced basal heart rate, systolic and mean arterial pressure, without influence on baroreflex sensibility and autonomic control, and no effect of PBMT was seen in rats with HF.