Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

Abstract

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

Effects of Transcutaneous Electrical Acupoint Stimulation on Patients with Stable Chronic Obstructive Pulmonary Disease: A Prospective, Single-Blind, Randomized, Placebo-Controlled Study

“…Four pairs of electrodes for TENS (6805-D model, Shantou City Medical Equipment Co., Ltd., Shantou City, China) were placed on the acupoints and fixed with adhesive tape. Treatment frequency was set for 2Hz according to the study by Franco et al 37 Electrodes of the same pair can only be connected at the same side to avoid direct contact across the body. In the control group (placebo acu-TENS), the devices were set as mentioned for the active treatment group, but no electrical current was applied.…”

Prospective trial examining safety and efficacy of microcurrent stimulation for the treatment of sinus pain and congestion

“…This sympathetic innervation by postganglionic nerve fibers facilitates vasoconstriction by the release of norepinephrine and subsequent smooth muscle contraction (Fischer et al 1993). Electrical stimulation of sympathetic nerve fibers can promote release of norepinephrine and vasoconstriction as evidenced by several studies investigating frequency ranges similar to that of the microcurrent study device (Franco et al 2014;Malm 1973;Mandel et al 2013). Vasoconstriction of arterioles and venous vessels, in the context of sinonasal inflammation, results in smaller vessel diameter, reduced edema and extravasation of inflammatory immune cells, as well as less nasal resistance to air flow, all of which can contribute to reduced symptom m severity and decongestant effects (Naclerio et al 2010).…”

Effects of Transcutaneous Electrical Nerve Stimulation in Autonomic Nervous System of Hypertensive Patients: A Randomized Controlled Trial

“…Currently, a further study has shown that the application of low frequency TENS in the ganglion region is more effective to increase vasodilation in lower limbs when compared to the application of TENS in acupunture points or with the control group, in healthy subjects, proving the change in sympathetic activity [24]. These changes in the vascular tone caused by TENS might stem from the interaction of the endothelial cell layer and physical or chemical stimuli that share a functional antagonism with the sympathetic nervous system in maintaining blood vessel tone, by the release of substances that affect the vascular tonus [25].…”