Influence of naloxone on the effects of high frequency transcutaneous electrical nerve stimulation in angina pectoris induced by atrial pacing

The influence of naloxone on the effects of high frequency transcutaneous electrical nerve stimulation in angina pectoris induced by atrial pacing was studied in 11 patients with severe coronary artery disease. The patients were catheterised and treated with transcutaneous electrical nerve stimulation on two occasions, double blind and in random order, with a single intravenous dose of saline or with a single intravenous dose of 50 mg naloxone. Treatment with transcutaneous electrical nerve stimulation increased tolerance to pacing and significantly improved lactate metabolism with placebo and with naloxone. The positive effects of transcutaneous electrical nerve stimulation were thus reproducible and not reversed by single intravenous doses of naloxone. The results indicate that the effects of transcutaneous electrical nerve stimulation on the heart are not mediated by beta endorphin but they do not exclude activation of more short-acting opioids such as delta or kappa receptor agonists (met-enkephalin or dynorphin or both) because naloxone has a low affinity for these receptors. Non-opioid mechanisms may also be important.     

Transcutaneous pacemaker in cardiovascular emergencies]

OBJECTIVES AND DESIGN OF THE STUDY: Retrospective study to evaluate the efficacy and tolerance of the transcutaneous cardiac pacemaker in the urgent treatment of asystole or severe bradycardia. SETTING: Coronary Care Unit (CCU) and emergency area of the central reference Hospital. PATIENTS: 24 patients, 20 males and four females, aged between 57 and 84 years (mean 70.4 +/- 7.9). Five pts were in asystole and 19 in severe bradycardia. INTERVENTIONS: The transcutaneous pacemaker used, was the "Cardio Aid Zoll NTP" model. The intensity of the electrical stimulation was increased progressively, until electrical capture or intolerable discomfort by the patients was achieved. We defined by electric efficacy, the visualization of pacing spike followed by a deflection due to ventricular depolarization; and by hemodynamic efficacy, the evidence of myocardial contraction, defined as a palpable pulse, synchronous with the pacing artefact. MAIN RESULTS: Stimulation threshold ranged from 30 to 140 mA (mean 67.7 +/- 23.4). The duration of pacing was from 15 minutes to 13 hours, being more than one hour in only four situations. From the 20 conscious patients, or the ones who got conscious, 15 (75%) tolerated well the stimulation. It was intolerable in five pts (25%). No significative side effects due to the use of transcutaneous pacemaker were observed. CONCLUSIONS: The transcutaneous pacemaker was efficient in the electric and hemodynamic stabilization in the majority of patients. It was generally well tolerated and without important side effects. We think that it may be a valid alternative to transvenous pacing technics in the treatment of asystole and severe bradycardia situations.     

Intracardiac Stimulation of Human Parasympathetic Nerve Fibers Induces Negative Dromotropic Effects:

Intracardiac Stimulation and Dromotropic Effect. Introduction : The dromotropic effects of intracardiac parasympathetic nerve stimulation have not been well studied; furthermore, the effects of radiofrequency ablation lesions on parasympathetic nerve stimulation are not clear.
Methods and Results : Group I: intracardiac electrical stimulation in the right posteroseptal and anteroseptal areas under different stimulation strengths; group II: intracardiac electrical stimulation before and 10 minutes after intravenous propranolol; group III; intracardiac electrical stimulation before and 5 minutes after intravenous atropine. Among the 10 patients with AV nodal reentrant tachycardia (group IV) and the 10 patients with atrial flutter (group V), atrial fibrillation was induced before and after successful ablation, and intracardiac electrical stimulation in the right posteroseptal area was performed before and after successful ablation. The maximal response and complete decay of the response occurred within 2 to 6 seconds of initiation or termination of parasympathetic nerve stimulation. This negative dromotropic effect disappeared after atropine was administered, but not after propranolol. After successful ablation, parasympathetic stimulation still induced negative dromotropic effects.
Conclusion : Electrical stimulation of parasympathetic nerve fibers near the posteroseptal and anteroseptal areas could induce a negative dromotropic effect, and this effect was preserved after successful radiofrequency ablation of slow pathway and isthmus conduction.     

静脉注射地尔硫对室上性心动过速的即时疗效和电生理作用

本文通过食管程序电刺激,对20例阵发性室上性心动过速(简称室上速)患者,其中房室结内折返性心动过速(AVNRT)5例,房室折返性心动过速(AVRT)15例,研究静脉注射地尔硫或维拉帕米(0.2mg/kg)的即时疗效和电生理作用。结果表明:①两药均有明显抑制房室结传导作用,对旁路的传导无明显抑制;②对正常窦房结功能者无明显抑制作用;③单剂静脉注射时血压轻度降低,副作用轻;④终止诱发或自发性室上速的有效率分别为60%(地尔硫组)和80%(维拉帕米组)。     

Catecholamine metabolism during pacing-induced angina pectoris and the effect of transcutaneous electrical nerve stimulation

The arterial levels of norepinephrine and epinephrine were estimated in 14 patients with severe coronary artery disease in order to assess the catecholamine metabolism during pacing-induced angina pectoris and to evaluate the effects of transcutaneous electrical nerve stimulation (TENS). Arterial levels of epinephrine and norepinephrine increased significantly during pacing to angina pectoris (p less than 0.05 and p less than 0.001, respectively), indicating that maximal atrial pacing induced an increase in sympathetic tone. At the corresponding pacing rate during TENS, myocardial lactate production was improved (p less than 0.01) and the ST segment depression was less pronounced (p less than 0.05). The maximal pacing rate during TENS was 141 +/- 24 compared to 123 +/- 19 (p less than 0.01) and the heart rate-blood pressure product was also significantly higher (p less than 0.01), suggesting an elevation of the anginal threshold by TENS. Systemic vascular resistance and systolic blood pressure were significantly reduced (both p less than 0.01). These beneficial results may be caused by a decrease in left ventricular afterload as reflected by a fall in systolic blood pressure and may be explained by reduced sympathetic activity. TENS may decrease the sympathetic activity either directly or indirectly as a consequence of pain inhibition. This hypothesis is supported by the fact that arterial levels of epinephrine and norepinephrine dropped during TENS in TENS responders.     

Transcutaneous cardiac pacing in the treatment of out-of-hospital pediatric cardiac arrests.

STUDY OBJECTIVE: To evaluate the effectiveness of transcutaneous cardiac pacing in out-of-hospital treatment of cardiac arrests in pediatric patients. DESIGN: We describe the outcome of patients treated during a prospective trial of transcutaneous cardiac pacing in the field. We compare their outcome with that of out-of-hospital arrests in submersion patients who were not paced. We identified patients from Seattle and King County Emergency Medical Services reports, hospitals, and medical examiner's registries. MEASUREMENTS AND MAIN RESULTS: Nine patients in cardiac arrest caused by drowning (six) and sudden infant death syndrome (three) were paced in the field. All were less than 6 years old. The one survivor was severely neurologically impaired and died six months later. Transcutaneous cardiac pacing produced electrical capture in two patients but no detectable pulse or blood pressure. Ten submersion patients less than 6 years old in cardiac arrest were not paced. One survived, with mild neurologic impairment at hospital discharge. CONCLUSION: Transcutaneous cardiac pacing was not effective and was not associated with improved survival.     

Differential involvement of conotoxin-sensitive mechanisms in neurogenic vasodilatation responses: effects of age

During aging there is a decline in sensory nerve function that is associated with reduced neurogenic inflammation and poor wound repair. The cellular mechanism(s) responsible for this decline in function with age is not well understood. We previously reported that sensory nerves in aged rats release sensory neuropeptides preferentially in response to low-frequency (5 Hz) as compared with higher-frequency (15 Hz) antidromic electrical stimulation, and that low-frequency transcutaneous electrical nerve stimulation accelerates wound healing. The present study investigates possible mechanisms for this preferential response. Using laser Doppler techniques, we have measured changes in blood flow in the base of vacuum-induced blisters induced in the rat hind footpad of young and old animals in response to low-frequency (5 Hz) or high-frequency (15 Hz) electrical stimulation (20 V, 2 ms for 1 minute) of the sciatic nerve. The relative contributions of the sensory neuropeptides, substance P and calcitonin gene-related peptide (CGRP), and of N-type voltage-gated calcium channels to the vascular responses were assessed by using the specific receptor antagonists RP67580, which is 2-(1-imino-2-(2 methoxy phyenyl) ethyl)-7,7 diphenyl-4 perhydroisoindolone-(3aR, 7aR); CGRP(8-37); and omega-conotoxin GVIA (Conus geographus), respectively. The results showed a greater involvement of substance P at high-frequency electrical stimulation and of CGRP at low-frequency stimulation. Our finding that omega-conotoxin-sensitive N-type calcium channel function was preserved with age and was only involved in the vascular response to low-frequency electrical stimulation could explain our previous report demonstrating beneficial effects of low-frequency transcutaneous electrical nerve stimulation to wound repair in aged animals. The current results have important practical implications for improving tissue repair in the aged.     

一种新型Visionwire标测导丝在心脏再同步化治疗中的应用

目的探讨一种新型Visionwire标测导丝在心脏再同步化治疗(CRT)左室电极植入过程中的应用价值。方法 5例因心力衰竭接受CRT的患者,分别采用Visionwire导丝及左室电极到达可植入左室电极的冠状静脉(CS)分支内进行起搏参数测试及电生理标测,比较两种方法的起搏参数测试、电生理标测结果及手术时间。结果在5例患者的16个CS分支中,两种方法所测的起搏参数值无显著性差异,二者的起搏阈值有强相关性(r=0.90,P<0.01),感知亦有相关性(r=0.67,P<0.01),二者最大起搏电压引起膈肌刺激的部位相似。应用Visionwire导丝可以进行局部电位电激动顺序标测。Visionwire导丝对单个CS分支进行起搏参数测定比应用左室电极进行起搏参数测定所需时间明显缩短(12.4±7.5 min vs 18.3±12.2 min,P<0.01)。结论应用Visionwire标测导丝可以预测CS分支的左室电极起搏参数,根据局部电位延迟可准确定位左室电极植入部位。     

Transcutaneous stimulation of the heart ventricles: its effectiveness, comfort during the examination and new diagnostic possibility

An attempt of assessment of transcutaneous cardiac pacing tolerance in healthy volunteers was carried out as well as abilities of this method utilization for examination of retrograde atrioventricular conduction. Ventricles were paced through highohm electrodes positioned on the chest wall with simultaneous recordings of transoesophageal ecg at the level of the left atrium and the sphygmogram of the right common corotid artery. Pacing perception threshold, skeletal muscle stimulation threshold, cardiac pacing threshold, algesic and myo-respiratory threshold of examination tolerance were estimated. Effective ventricular pacing within the range of stimulation tolerance was obtained in 10 of 15 patients (67%). Mean ventricular pacing threshold was higher than pacing perception and skeletal muscles stimulation thresholds (42 mA; 9.4 mA and 20.2 mA). Ventricular pacing threshold was lower than algesic and muscles thresholds of examination tolerance (60-70 mA) warranting relatively good tolerance of transcutaneous cardiac ventricular pacing. In 8 of 10 persons with effective ventricular stimulation retrograde a-v nodal conduction was stated which proved that transcutaneous cardiac ventricular stimulation can be used for noninvasive assessment of retrograde a-v nodal conduction.     

Vagal stimulation prior to atrial rapid pacing protects the atrium from electrical remodeling in anesthetized dogs.

Atrial electrical remodeling is thought to be the cause of the maintenance of atrial fibrillation (AF). Although the initiation and maintenance of AF is partially associated with autonomic nervous tone, vagally mediated AF does not tend to become permanent. Therefore, the effects of preceding vagal stimulation (VS) on the atrial effective refractory period (ERP) under electrical remodeling conditions were investigated in anesthetized dogs. Atrial ERPs were measured at 5 sites before and after a 7-h period of atrial rapid pacing in the control group. In the VS group, the vagus nerve was stimulated for 20 min before a period of atrial rapid pacing. Atrial rapid pacing shortened the ERP at each site in the control group (electrical remodeling). On the other hand, atrial rapid pacing after VS did not shorten the ERP at any site in the VS group. Tetrodotoxin, which was administered into the fatty tissue overlying the right atrial side of the right pulmonary vein junctions, blocked the protective effect of VS against the shortening of the ERP induced by atrial rapid pacing. In contrast, atropine did not interfere with such protective effects. These results suggest that VS prior to atrial rapid pacing protects the atrium from atrial electrical remodeling.     

Haemodynamic effects of molsidomine in patients with severe chronic coronary disease

The haemodynamic effects of a single dose of intravenous molsidominewere assessed in 12 patients with severe coronary disease. Theinvestigation was carried out at rest during angina inducedby pacing and after molsidomine during pacing at the rate atwhich angina had been produced. During angina, left ventricularsystolic and end-diastolic pressure rose, left ventricular strokework fell and coronary flow and myocardial oxygen consumptionincreased by 58.3% above the control levels. After the administrationof molsidomine, atrial stimulation was not followed by anginaand there were no significant changes in systolic blood pressure.Left ventricular end-diastolic pressure fell sharply and coronaryflow and myocardial oxygen consumption were only 38% and 33%higher, respectively, than the control levels. The beneficialeffects of molsidomine in ischaemic heart disease, therefore,are the result of peripheral vasodilation which, by reducingthe preload and after load, lowers the oxygen requirements ofthe myocardium and thus increase the threshold for angina. Adirect action on the coronary network can not be excluded butif such an action does exist it must be very small in the lightof the marked systemic effect.     

经皮电神经刺激对脑卒中偏瘫患者下肢痉挛及运动功能的影响

目的 探讨经皮电神经刺激（TENS）对脑卒中偏瘫患者下肢痉挛及运动功能的影响.方法 按纳入标准将60例偏瘫患者随机分为试验组和对照组,每组30例.对照组采用常规药物及康复治疗,试验组在此基础上增加经皮电神经刺激治疗,分别于治疗前及治疗后进行患侧下肢踝跖屈肌临床痉挛指数（CSI）评定、Fugl-Meyer运动功能评定（FMA）及最大步行速度（MWS）评定,比较两组治疗效果.结果 治疗后对照组CSI评分、FMA、MWS分别为（10.58±2.50）分、（19.01±4.67）分、（35.93±6.78） m/min,试验组CSI、FMA、MWS分别为（8.41±2.29）分、（23.41±5.45）分、（41.52±8.16） m/min.与对照组比较,试验组踝跖屈肌痉挛明显缓解（t=3.506、P〈0.05）,下肢运动功能及最大步行速度明显提高（t=3.358、t=2.886、P〈0.05）.结论 经皮电神经刺激可降低脑卒中偏瘫患者踝跖屈肌痉挛,提高下肢运功功能,改善步行能力.     

The effects of transcutaneous electrical nerve stimulation in patients with severe angina pectoris

The pain-relieving effects of transcutaneous electrical nerve stimulation (TENS) were investigated in patients with severe angina pectoris first with respect to systemic and coronary hemodynamics and myocardial metabolism during pacing-induced angina and second in a controlled long-term study. Two series of patients with severe angina pectoris (NYHA class III to IV) were studied (13 patients in the pacing study and 23 in the long-term study). In the pacing-induced angina study there was increased tolerance to pacing (142 +/- 23 compared with 124 +/- 20 beats/min tolerated, p less than .001), improved lactate metabolism (2 +/- 36% compared with -18 +/- 43%, p less than .01), and less pronounced ST segment depression (2.3 +/- 1.1 compared with 2.9 +/- 2.6 mm, p less than 0.05) with TENS. In the long study the effects of TENS were measured by means of repeated bicycle ergometer test, frequency of anginal attacks, and consumption of short-acting nitroglycerin. TENS was used regularly for 1 hr three times per day. The TENS treatment group had increased work capacity (637 +/- 308 vs 555 +/- 277 W . min, p greater than .001), decreased ST segment depression (2.3 +/- 1.1 vs 3.6 +/- 1.6 mm, p less than .001), reduced frequency of anginal attacks (p less than .05), and reduced consumption of short-acting nitroglycerin per week (p less than .05) compared with the control group. The observed effects were mainly due to decreased afterload resulting from systemic vascular dilatation.     

Preliminary results of peripheral transcutaneous neuromodulation in the treatment of idiopathic fecal incontinence

Purpose Few therapeutic tools are available for treating idiopathic anal incontinence. Sacral neuromodulation appears to be effective in selected patients but requires surgical implantation of a permanent electrical stimulator. The aim of this work was to assess the efficiency of posterior tibial nerve (PTN) transcutaneous electrical nerve stimulation (TENS) in the treatment of anal idiopathic incontinence.Methods Ten women were treated by PTN TENS, 20 min a day for 4 weeks. Functional results were evaluated by Wexner’s incontinence score and anorectal manometry.Results Eight of the ten patients showed a 60% mean improvement of their incontinence score after 4 weeks. This improvement remained stable over the 12-week follow-up period. Manometric parameters did not differ before and after stimulation.Conclusion PTN neuromodulation without surgically implanted electrode could represent a safe and low-cost alternative to permanent sacral neuromodulation for idiopathic anal incontinence.     

经食管心房调搏在特发性室速诊断中的应用

目的探讨经食管心房调搏在特发性室性心动过速(室速)中的应用价值。方法回顾分析30例特发性室速患者的经食管心房调搏资料。结果经食管心房调搏基础刺激诱发心动过速6例(20%),静脉滴注异丙肾上腺素激发后刺激诱发12例(40%),心动过速时通过食管心电图证实QRS波群与P波非1∶1关系,且心室率>心房率而确诊为室速26例(86.67%)。心动过速自行终止5例(16.67%),药物或其它方法终止19例,经食管心房调搏超速刺激法终止6例(20%)。结论经食管心房调搏对诱发和确诊室速有较大的帮助,经食管心房调搏终止室速成功率不高。     

The study of the central motor conduction time to the leg: normal findings and methodologic observations

Central motor conduction time (CMCT) is calculated by subtracting latencies from each other measured to a target muscle after transcranial brain stimulation and after stimulation of lumbar spinal nerve roots. Transcranial magnetoelectrical stimulation of the motor cortex has proved to be the most useful method. However this is not true for transcutaneous stimulation of lumbar roots. In healthy subjects electrical root stimuli given at T12/L1 produced compound muscle responses in Tibialis anterior muscles in all 18 trials. However, magnetoelectrical stimulation (100% stimulus strength) evoked responses in only 8 (Novametrix) and 12 out of 18 trials (Cadwell). Stimulation with the Digitimer D190 was less effective. Additionally compound responses after electrical root excitation were more consistent and they had a higher amplitude compared with magnetoelectrical stimulation. Regarding to these results electrical lumbar root stimulation is thought to be the advantageous method despite it is slightly more uncomfortable. Therefore normal results of CMCT to Tibialis anterior (shown in Table 1) are measured after magnetoelectrical transcranial (Digitimer D190) and transcutaneous electrical stimulation of spinal nerve roots. If the peripheral motor conduction is delayed normal values have to be adapted since CMCT is thought to involve a proximal anterior root segment. An intraspinal motor conduction time can be calculated from CMCT to upper and lower extremities.     

Antiinflammatorische und analgetische Stromformen

The objective of this article is an assessment of the evidence on antiinflammatory and analgesic current in rheumatology. Three trials on the effects of TENS (transcutaneous electrical nerve stimulation) with RA-patients (rheumatoid arthritis) showed good analgesic effect, while one study on EMS (electrical muscle stimulation) demonstrated a benefit in muscle strength and function. No anti-inflammatory effect could be verified. The overall validity is limited due to the small number of studies and the methodical quality of the analyzed trials.     

Initial clinical experiences with mechanical heart stimulation

Rhythmical extrathoracic mechanical stimulation can produce cardiac systoles. The study was designed to determine the usefulness of this procedure in bridging the time gap between the occurrence of asystole or symptomatic bradycardia and the beginning of temporary cardiac pacing or the restoration of a sufficiently high spontaneous heart rate. The mechanical stimulator was used on 31 patients. In 10 patients sufficient circulation with palpable pulse in the femoral artery could be restored. Five patients needed temporary electrical pacing. Five of the patients successfully treated mechanically died within 24h of terminal circulatory collapse or electromechanical dissociation. Five patients could be dismissed from hospital, with only one of them needing permanent cardiac pacing. Twenty of the 21 patients who could not be stimulated mechanically died. Seventeen of those showed electromechanical dissociation when treated with transvenous endocardiac stimulation, three suffered from terminal circulatory collapse. In one patient with an instable thorax sufficient circulation could be obtained by extrathoracic mechanical stimulation. Four patients were not stimulated electrically because of old age and polymorbidity. Problems in using the extrathoracic mechanical stimulation are discussed and compared with endocardiac and extrathoracic electrical stimulation.     

QT time and the ventricular refractory period in programmed electrical stimulation of the heart in patients with ventricular and supraventricular tachycardias--effect of sotalol

The QT-interval in the surface electrocardiogram (usually lead II) and the effective refractory period of the right ventricle (ERP-V) were investigated in 16 patients with documented supraventricular tachycardia (SVT) and in 18 patients with documented ventricular tachycardia (VT) during basic pacing (QT1) and programmed stimulation of the right ventricular apex (QT2) (single-test stimulation at 3 different rates, BCL: 600 ms, 500 ms, 430 ms). The effects of intravenous and oral Sotalol were analysed in the SVT-group. An increase in heart rate was followed by a significant decrease of the QT-intervals and ERP-V in both groups. The QT-intervals and the ERP-V were statistically significantly prolonged by intravenous Sotalol. The VT-group showed a statistically significant longer shortest QT2-interval during programmed stimulation, which can be explained by a greater dispersion of action potentials leading to an inhomogenous ventricular recovery process, which may represent the electrical substrate for the arrhythmia.     

Influence of tachycardia cycle length and antiarrhythmic drugs on pacing termination and acceleration of ventricular tachycardia

We examined the influence of ventricular tachycardia (VT) cycle length and antiarrhythmic drugs on the frequency of VT termination and acceleration by single and double extrastimuli and right ventricular burst pacing. In 57 patients, 89 episodes of sustained VT (32 control, 57 drug) were induced by programmed electrical stimulation. Overall, 60 of 89 (67%) episodes of ventricular tachycardia were terminated by means of programmed electrical stimulation. In patients with relatively slow ventricular tachycardia (VT cycle length greater than or equal to 350 msec) pacing terminated 37 of 44 (84%) episodes but terminated only 24 of 45 (51%) episodes of more rapid VT (VT cycle length less than or equal to 349 msec, p less than 0.005). Pacing successfully terminated VT in nine of 49 (18%) episodes using a single extrastimulus, 22 of 52 (42%) episodes using double extrastimuli, and 40 of 66 (61%) episodes using burst right ventricular pacing. VT acceleration occurred in none of 49 attempts with a single extrastimulus, in eight of 52 (15%) attempts with double extrastimuli, and in 12 of 66 (18%) attempts using burst right ventricular pacing. During therapy, the frequency of either ventricular tachycardia termination or acceleration did not change regardless of the pacing termination method used. However, by prolonging the mean VT cycle length from 311.1 +/- 82.2 msec to 401.9 +/- 103.5 msec (p less than 0.01), drugs increased the overall frequency of VT termination. We conclude that: (1) pacing terminates VT more frequently if the VT cycle length is long and if right ventricular bursts are used, (2) burst right ventricular pacing increases the risk of VT acceleration, and (3) drugs increase the frequency of ventricular tachycardia termination by prolonging VT cycle length but do not affect frequency of VT acceleration.