Effectiveness of Transcutaneous Electrical Stimulation on the Autonomous and Cardiovascular System on Healthy Young People; a Prospective, Randomized, Single-blind, Controlled Pilot Study
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 30
- 试验地点
- 2
- 主要终点
- RMSSD
研究概览
简要总结
Cardiovascular disease is one of the most important causes of death and disability in the world. An autonomic imbalance is associated to cardiovascular risks and disorders. Electrical stimulation (ES) applied by surface electrodes is a non-invasive therapeutic approach with low side-effects. In the last years, some studies had investigated the effects of ES on the autonomic nervous system and cardiovascular system. However, different intensities, frequencies and electrode locations had been used, which makes difficult to clarify the optimal parameters.
The aim of this study is to analyze the effects of ES on autonomic nervous modulation in healthy subjects comparing three different locations of application for ES.
Participants will be aleatory assigned to one of three groups for a single-session of 20-minute transcutaneous ES: a) an auricular intermittent ES in an area that is believed to be connected to the vagal nerve (cymba conchae); b) an auricular sham intermittent ES, meaning a real ES but applied on an ear location not connected to the vagal nerve (scapha); and c) an upper back continuous ES (C7-T4), a placement that is thought to be connected to the stellate (sympathetic) ganglion. All the protocols will be stated at a non-painful intensity. After that, the hand grip exercise will be executed.
The heart rate variability (HRV) and heart frequency (HR) will be measured in four main times: the baseline, in the final minutes of the ES, after the ES and after finishing the hand grip exercise. Blood pressure will be measured also at all the time points except during the ES due to the possibility of interferences. Adverse effects will be assessed after ES and 48 h later. The study will provide initial knowledge about how different electrical stimulation locations contribute to reduce sympathetic excitation and improve the sympathovagal balance.
详细描述
Electrical stimulation (ES) of the nervous system, also denominated as neuromodulation, has been investigated for diverse conditions as cardiovascular diseases, chronic pain and psychiatric conditions. It is unknown which locations and parameters can be more effective and better tolerated. The transcutaneous ES is a non-invasive technique which has fewer side-effects than subcutaneous vagus nerve stimulation.
The aim of this study is to analyze the acute effects of transcutaneous ES on autonomic nervous modulation by heart rate variability (HRV), heart frequency (HF) and blood pressure (BP) in healthy subjects comparing three different locations for the ES, before and after a hand-grip exercise. In addition, the tolerance to the current, the side-effects and the perceived exertion will be compared.
Once the participants have given their informed consent and had been checked for exclusion criteria, are invited to an experimental session. Subjects will be advised to refrain from caffeine or alcohol for 12 h and vigorous exercise for at least 24h prior to the intervention.
The participants will remain sitting during the entire session and will be instructed to stay awake and avoid movement. Grip strength will be evaluated by a hydraulic dynamometer (Saehan model SH5001). Participants will remain seated on a chair with their feet and trunk supported, shoulders adducted, elbows flexed at 90º, forearms in neutral position, and wrists with 0º-30º extension. Subjects will be instructed to perform a maximum isometric contraction for three to five seconds, and the peak force will be recorded. Three evaluations will be made with an interval of one minute between them. If the examiner would recognize some compensatory movement by the participant, a new measurement would be taken and registered.
The volunteers will be randomized by sex to one of three groups: cymba conchae at the right ear (active group); C7-T4 placement (active group), scapha at the right ear (sham-group). These three arms will be denominated as Transcutaneous Vagus Electrical Nerve Stimulation (t-VNS); Transcutaneous Sympathetic Ganglion Electrical Nerve Stimulation (t-SNS); and Sham Transcutaneous Vagus Electrical Nerve Stimulation (sham t-VNS), and. Allocation concealment, stratified by sex, will be ensured by the use of sealed envelopes containing the treatment allocation. The sequence will be generated using a computer program by a researcher not implicated in the experimental sessions. The envelopes will be opened just before determining the amplitude for stimulation. The stimulation location will be wiped down with alcohol and the minimum intensity, at which the stimulus is perceived, will be evaluated for the auricular locations, whereas minimum amplitude for muscle contraction between the electrodes will be assessed in cervico-thoracic location.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Participant)
盲法说明
Allocation concealment, stratified by sex, will be ensured by the use of sealed envelopes containing the treatment allocation
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •University students and academic or administrative staff, non smokers, self-perceived as healthy
排除标准
- •No history of neurological, neurosurgical, psychiatric, cardiological disease, pulmonary disease, syncope, seizure, head trauma, cranial or neck surgery, aneurisms, or any condition or treatment which could affect the functioning of the autonomous nerve system or the cardiovascular system (by self-report).
- •BMI of 30 or over
- •High blood pressure (systolic blood pressure of 140 mmHg or over, or diastolic blood pressure of 90 mmHg or over)
- •Spontaneous respiratory rate under 10 breaths per minute
- •Professional athletes
- •Inability to reach the minimum amplitude required during electrical stimulation
- •Any arm or hand pain (dominant side)
- •Any contraindication for electrical stimulation (pregnancy or risk or being pregnant, any implanted electronical device, irritation or pain at the skin location for the electrodes, intolerance to electrical stimulation) or any condition which could affect the placement of the electrodes or the perception of the electrical stimulus.
结局指标
主要结局
RMSSD
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Root mean square of successive RR interval differences (ms). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
SD1
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
The poincaré plot short term variability (ms). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
SD2
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
The poincaré plot long term variability (ms). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
RR
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
The time of RR intervals (ms) will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland). The mean values of RR intervals (ms) and the standard deviation of all RR intervals (ms) will be obtained.
HF
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
High frequency refers to HRV frequency band (0.15-0.4 Hz). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
LF
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Low frequency refers to HRV frequency band (0.04-0.15 Hz). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
Mean heart rate
时间窗: 5 minutes before Electrical Stimulation, during 20 minutes of Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
The mean frequency will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
pNN50
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Relative number of successive RR interval pairs that differ more than 50 ms (percentage). It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
Diastolic blood pressure
时间窗: 5 minutes before Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Blood pressure will be continuously acquired by SOMNOtouch NIBP (Somnomedics, GmbH, Randersacker, Germany) that is an ambulatory cuffless device for continuous (beat-to-beat), noninvasive BP monitoring. The system consists of a finger photoplethysmograph and three ECG leads, connected to a watch-like control unit placed at the wrist level and equipped with a screen where beat-to-beat pulse waveform, ECG, and PTT changes are displayed. All these measurements are unified to obtain the diastolic blood pressure in mmHg.
LF/HF
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
The ratio of LF to HF power will be calculated along with normalised LF/HF where baseline values will set to 1. It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
SD2/SD1
时间窗: 5 minutes before Electrical Stimulation, During 20 minutes Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Poincaré plot long and short term variability ratio. It will be obtained from Polar S800 with Polar T31 transmitter (Polar Electro, Kempele, Finland), and it will be extracted with Kubios software (University of Eastern Finland, Kuopio, Finland).
Systolic blood pressure
时间窗: 5 minutes before Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Blood pressure will be continuously acquired by SOMNOtouch NIBP (Somnomedics, GmbH, Randersacker, Germany) that is an ambulatory cuffless device for continuous (beat-to-beat), noninvasive BP monitoring. The system consists of a finger photoplethysmograph and three ECG leads, connected to a watch-like control unit placed at the wrist level and equipped with a screen where beat-to-beat pulse waveform, ECG, and PTT changes are displayed. All these measurements are unified to obtain systolic blood pressure in mmHg.
Mean arterial pressure
时间窗: 5 minutes before Electrical Stimulation, 5 minutes after Electrical Stimulation, During 3 minutes hand-grip exercise, 15 minutes after hand grip exercise
Blood pressure will be continuously acquired by SOMNOtouch NIBP (Somnomedics, GmbH, Randersacker, Germany) that is an ambulatory cuffless device for continuous (beat-to-beat), noninvasive BP monitoring. The system consists of a finger photoplethysmograph and three ECG leads, connected to a watch-like control unit placed at the wrist level and equipped with a screen where beat-to-beat pulse waveform, ECG, and PTT changes are displayed. All these measurements are unified to obtain the mean arterial pressure in mmHg.
次要结局
- Electrical simulation tolerance(20 minutes after initiating electrical stimulation)
- Rating of perceived effort(Immediately after the hand grip exercise)
- Adverse effects(At 20 minutes after initiating electrical stimulation and at 48 hours after the electrical stimulation)
研究者
Alicia Martínez Rodríguez
Lecturer, PhD, MSC, PT. Faculty of Physical Therapy.
Universidade da Coruña