Sandra do Amaral Sartori, Cinara Stein, Christian Correa Coronel, Fabricio Edler Macagnan and Rodrigo Della Mea Plentz* Pages 66 - 71 ( 6 )
Background: Patients with hypertension have altered autonomic nervous system function, which are increased sympathetic activity. Transcutaneous Electrical Nerve Stimulation (TENS) is a useful modality for pain control and has also been shown to be effective in the reduction of sympathetic activity in healthy subjects and individuals with cardiovascular diseases.
Objective: The aim of this study was to verify the effects of transcutaneous electrical nerve stimulation by the evaluation of heart rate variability (HRV) in patients with essential hypertension.
Method: Twenty-eight patients received an application of low-frequency TENS(4 Hz) n=8, highfrequency TENS (100 Hz) n=10 or placebo TENS n=10 in paravertebral ganglionar region during thirty minutes.
Results: After 4 Hz TENS, there was a decrease in the low-frequency (LFn.u.) component (57.71±9.46 vs 45.58±13.51, p<0.026) and an increase in the high-frequency (HFn.u.) component (33.03±13.83 vs 45.83±20.19, p <0.05) of HRV. After 100 Hz TENS and placebo, there were no changes in the LF and HF components. No significant differences were found in systolic blood pressure with low-frequency TENS (129.37± 15.48 vs 126.69 ± 15.21, p<0.490). There was an increase, although not significant, with high-frequency TENS (131.00 ± 15.97 vs 138.75 ± 25.79, p<0.121) and placebo (133.80 ± 29.85 vs 134.80 ± 29.72, p< 0.800). No differences were found in the diastolic blood pressure with low-frequency TENS and placebo, but there was a significant increase in high-frequency TENS (81.00 ± 11.78 vs 85.65 ± 13.68, p< 0.018).
Conclusion: Low-frequency TENS decreases sympathetic nervous system activity and increases parasympathetic nervous system activity and high-frequency TENS increases diastolic blood pressure, when applied on the paravertebral ganglionar region in the hypertensive patients.
Hypertension, transcutaneous electrical nerve stimulation, autonomic nervous system, sympathetic nervous system, parasympathetic nervous system, heart rate variability.
Universidade Federal de Ciencias da Saude de Porto Alegre-UFCSPA, Porto Alegre-RS, Universidade Federal de Ciencias da Saude de Porto Alegre-UFCSPA, Porto Alegre-RS, Instituto de Cardiologia/Fundacao Universitaria de Cardiologia-IC/FUC, Porto Alegre-RS, Universidade Federal de Ciencias da Saude de Porto Alegre-UFCSPA, Porto Alegre-RS, Universidade Federal de Ciencias da Saude de Porto Alegre-UFCSPA, Porto Alegre-RS