Changes of Monophasic Action Potential Duration and Effective Refractory Period of Three Layers Myocardium of Canine during Acute

Summary： The effect of acute ischemia on the electrophysiological characteristics of the three layers myocardium of canine in vivo was investigated. Twelve canines were divided into two groups randomly： acute ischemia （AI） group and sham operation （SO） group. By using the monophasic action potential （MAP） technique, MAP and effective refractory period （ERP） of the three layers myocardium were measured by specially designed plunge needle electrodes and the transmural dispersion of repolarization （TDR） and transmural dispersion of ERP （TDE） were analyzed. The results showed that in the AI group, MAP duration （MAPD） was shortened from 201.67±21.42 ms to 169.50±13.81 ms （P〈0.05）, but ERP prolonged to varying degrees and TDE increased during ischemia. In the SO group, MAPD and ERP did not change almost. Among of the three layers myocardium of canine, MAPD was coincident in two groups. It was concluded that during acute ischemia, MAPD was shortened sharply, but there was no significant difference among of the three layers myocardium. The prolonged ERP was concomitant with increased TDE during acute ischemia, which may play an important role in the occurrence of arrhythmias induced by acute ischemia. These findings may have important implications in arrhythmogenesis.

Effects of Electric Stimulations Applied during Absolute Refractory Period on Cardiac Function of Rabbits with Heart Failure

The effects of electric currents applied during absolute refractory period （ARP） on the cardiac function of rabbits with heart failure due to myocardial infarction （MI）, and the safety of this method were investigated. Thirty rabbits were randomly assigned equally to 3 groups： sham-operated group, LV-anterior wall cardiac contractility modulation （LV-CCM） group, and septum-CCM （S-CCM） group. A thoracotomy was performed on all the rabbits. Electric pulses were delivered during the ARP on the anterior wall of left ventricle in CCM group and in the septum in S-CCM group, respectively. The left ventricular systolic pressure （LVSP） and maximum positive left ventricular pressure change （＋dp/dtmax）, heart rates, ventricular tachycardia, ventricular fibrillation were observed. It was found that, as compared with the baseline, LVSP, and ＋dp/dtmax were significantly increased, on average, by 15.2% and 19.5% in LV-CCM group （P〈0,05）, and by 8.5% and 10.8% in S-CCM group （P〈0.05）. LVEDP was significantly decreased and -dp/dtmx increased both in LV-CCM group and S-CCM group （P〈0.05）. CCM had no effect on heart rate and induced no arrhythmia in short time. It is concluded that electric currents delivered during the ARP could significantly enhance the contractility of myocardium safely, suggesting that CCM stimulation is a novel potent method for contractility modulation.

Effects of Electric Stimulations Applied During Absolute Refractory Period on Ventricular Muscle from Rabbits

Objectives To investigate the influences of electric signals applied during absolute refractory period (ARP) on the contractility of isolated papillary muscle from rabbits. Methods Papillary muscle was exercised from the right ventricle and was paced at 1 Hz. Biphasic square wave current pulse was delivered during the absolute refractory period (called CCM) in isolated, superfused, isometrically contractility rabbit papillary muscle. The peak tension (PT) of papillary muscle, as well as maximum positive tension change ( + dT/dtmax), were observed. Results Compared with the baseline, both PT and + dT/dtmax significantly increased during CCM stimulation by 18.2% and 21.4% respectively (P < 0. 05) . In addition, PT increased significantly with one or two beats following CCM signal application and reached a. new steady state level after a few beats. Once the CCM signals were turned off, the PT returned to the approximately baseline level ( P < 0. 05). Moreover, the effect of CCM on PT was dose - response to voltage. The obvious effect was at higher voltage. No effect was observed at lower voltage. Conclusions Electric signals delivered during the absolute refractory period can rapidly enhance the contractility of myocardium, which suggests that CCM signal is a novel potent method for contractility modulation.

Effects of Amiodarone on Transmural Dispersion of Ventricular Effective Refractory Periods across Myocardial Layers in the Normal and Hypertrophic Canine Heart

The effects of amiodarone on transmural dispersion of ventricular effective refractory periods （ERPs） in the normal and hypertrophic canine heart were investigated in vivo. By using the programmed stimulation protocol, the ERPs of epicardium （Epi）, midmyocardium （Mid） and endocardium （Endo） were measured by inserting specially-designed electrodes into the three myocardial layers before and after mainlining of amiodarone. No significant ERPs-dispersion was observed in the three layers before and after mainlining of amiodarone in the normal group. In contrast, ERPs of all the three layers were prolonged in the hypertrophic heart, while the ERPs-dispersion was reduced significantly after mainlining of amiodarone. The ERPs-dispersion was significantly increased in the hypertrophic heart but not in the normal heart using ＂long-short＂ and ＂short-long＂ interval stimulation technique. It was concluded that （1） the differences in ERPs-dispersion among the three layers were significant in hypertrophic heart, and differences were not significant in normal canine heart; （2） ERPs of each three-myocardial layers were significantly prolonged after using amioda- rone, but the ERPs-dispersion decreased in hypertrophic heart and （3） the programmed extrastimulus technique of ＂long-short＂ and ＂short-long＂ intervals increased the transmural ERPs-dispersion in the hypertrophic heart.

Effect of β_3-adrenoceptors on Ventricle Fibrillation Threshold and Effective Refractory Period in Rats With Heart Failure

Objectives To observe the effect of β3-Adrenoceptor （AR） on ventricle fibrillation threshold （VFT） and effective refractory period （ERP） in rats with heart failure. Methods Rats were randomized into control group and heart failure group. The expression of β3-ARmRNA was detected with RTPCR; The VFT, ERP, LVESP,LVEDP, ＋dp/dtmax and -dp/dtmax was measured at the same time with administration of BRL37344 （ 2 nmol / kg, β3- AR agonist）. Results ①Both the expression of β3-AR mRNA and the proportion increased in rats with heart failure in comparison with control rats （0.028 vs. 0.011 and 5.4% vs 1.2%, P 〈 0.05）;② ERP was longer in rats with heart failure than control group （70.5±5.5 ms vs 59.5±6.4ms, P 〈 0.05） and there was no difference of ERP in rats with heart failure with administration of BRL37344 （73.0±4.8 ms vs 70.5± 5.5 ms, P 〉0.05）; ③VFT was lower in rats with heart failure than control group（10.9±0.8 mv vs 30.5± 1.3 mv, P〈 0.05） and decreased obviously in rats with heart failure with administration of BRL37344 （7.1±0.6 mv vs 10.9±0.8 mv, P 〈 0.05） ; The decrease of VFT correlated with the effect on LVESP, ＋dp/ dtmax,-dp/dtmax of BRL37344 and the expression of β3-AR mRNA （correlation coefficient： 0.788, 0.708, 0.759, 0.787; P 〈 0.05）. Conclusions The expression of β3-AR mRNA of left ventricle was obviously increased in rats with heart failure, and activation of β3-AR had no effect on ERP but could decreased VFT which correlated with the effect of β3-AR on LVESP, ＋dp/dtmax, -dp/dtmax and the expression of β3-AR mRNA.

Effects of Electrical Stimulation During Absolute Refractory Period on Contraction and Relaxation of Cardiomyocytes from Normal Guinea - pigs

Objectives To investi-gate the effect of electrical stimulation during absolute refractory period on contraction and relaxation of ventricular myocytes from normal guinea - pigs. Methods The guinea - pig ventricular myocytes were obtained by enzyme digesting, and the extent of its contraction and relaxation and Ca2+ transient were recorded through the motion edge detection system. Results (1) The contracting extent of guinea - pig ventricular myocytes increased 15.45±6.48% , and the peak velocity of shorting (contraction) and the peak veloci ty of relengthening (relaxation) increased 15.97 ± 8.37% and 21. 63±8. 06% respectively (n = 10); (2) The extent of ventricular myocytes fluorescence ra tio(360/380) (F360/F380) increased 22. 55±9. 08%, and the peak velocity of ventricular myocytes F360 /F380 increased 36. 75 ± 9. 77% and 23. 62±4. 47% during shorting and relengthening respectively (n = 6) . Conclusions Appropriate electrical stimulation may strengthen the contracting and relaxing function of normal guinea - pig ventricular myocytes.

Influence of Selective Edge Removal and Refractory Period in a Self-Organized Critical Neuron Model

A simple model for a set of integrate-and-fire neurons based on the weighted network is introduced.By considering the neurobiological phenomenon in brain development and the difference of the synaptic strength,weconstruct weighted networks develop with link additions and followed by selective edge removal.The network exhibitsthe small-world and scale-free properties with high network effficiency.The model displays an avalanche activity ona power-law distribution.We investigate the effect of selective edge removal and the neuron refractory period on theself-organized criticality of the system.

Variation of repetitive cortical spreading depression waves is related with relative refractory period： a computational study

Cortical spreading depression （CSD） is an important experimental model for diseases such as stroke, epilepsy and migraine. Previous observations indicated that the amplitude and velocity of the typical direct current potential shift during repetitive CSD waves were varying. The recovery state of the tissue was found related with the variation of successive CSD waves. A computational model in this paper aimed to investigate the role of relative refractory period of CSD. This model simulated that continuous injection of KCI solution induced repetitive CSD waves. The first CSD wave often had a larger amplitude and faster velocity than those of the succeeding secondary waves. The relative refractory period lasted much longer than the recovery of ions turbulence. If the induction interval was long enough for recovery, a series of CSD waves would have the same profile asthe first one. In the relative refractory period, an early stimulation might lead to a late initiation of CSD, i.e., ＂haste makes waste＂. The amplitude and velocity of CSD waves were found increasing with the initiation interval and asymptotic to those of the first CSD wave. This study verified that the propagation dynamics of CSD waves is modulated by the relative refractory period. It suggested that the refractory period is critical for preventing undesirable CSD waves.

A Reevaluation of the Critical Membrane Potential of the Effective Refractory Period in Guinea Pig Ventricular Fibres

The traditional critical membrane potential (CMP), -55—-60mV, which corresponds to effective refractory period (ERP), was anew investigated in guinea pig ventricular muscle fibres. The electrical and contractile responses to the stimulus during repolarization of action potential (AP), particularly from+10 to -60 mV, were observed. One third of 35 tested cells displayed testing action potential (TAP) and local response at≥-54 mV when they were stimulated by testing pulses in 37℃ normal Tyrode’s solution. Potential level of TAP which occurred earliest was at -30 mV and that of local response which appeared earliest was at 0 mV during repolarization among 95 systematic tests. Most of the TAPs belonged to the slow response potential type. The ratio of TAP evoked at ≥-54 mV initial membrane potential (IMP) was as high as 86% when the experiment was carried out in 37℃ 1.5 mmol KC1/L Tyrode’s solution. In view of distribution of IMPs of TAPs, the CMP of ERP in guinea pig ventricular muscle fibres was

难治性癫痫的外科治疗进展

在癫痫患者中,药物难治性癫痫一直占据相当比例。这部分患者在经过精确的评估后或可通过外科治疗的手段达到发作缓解。本文阐述了难治性癫痫的术前神经电生理和影像评估方法,并结合最新临床研究进展,针对不同类型癫痫总结手术治疗方案,补充阐述了无创治疗方法,且在此基础上探讨了癫痫外科治疗未来发展趋势。

银杏叶提取物注射液联合双联抗血小板治疗急性脑梗死恢复期患者的效果

目的:银杏叶提取物注射液联合双联抗血小板治疗急性脑梗死(ACI)恢复期患者的效果。方法:回顾性分析2021年2月至2023年2月该院收治的94例ACI恢复期患者的临床资料,依据治疗方法不同将其分为对照组和观察组各47例。两组均给予降脂、抗感染、营养神经等常规治疗,在此基础上,对照组采用双联抗血小板治疗,观察组在对照组基础上联合银杏叶提取物注射液治疗。比较两组临床疗效,治疗前后美国国立卫生研究院卒中量表(NIHSS)评分、血清炎性因子[白细胞介素-6(IL-6)、纤维蛋白原(FIB)]水平、凝血功能指标[凝血酶时间(TT)、凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、纤维蛋白原(FIB)]水平,以及不良反应发生率。结果:观察组治疗总有效率为93.62%(44/47),对照组治疗总有效率为82.98%(39/47),差异无统计学意义(P>0.05);观察组基本痊愈率为29.79%(14/47),高于对照组的12.77%(6/47),差异有统计学意义(P<0.05)。治疗后,观察组血清FIB、hs-CRP、IL-6水平均低于对照组,TT、PT、APTT值均高于对照组,差异有统计学意义(P<0.05)。两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:银杏叶提取物注射液联合双联抗血小板治疗ACI恢复期患者可提高临床疗效,减轻神经功能损伤,降低炎性因子水平,改善凝血功能,效果优于单纯双联抗血小板治疗。

奥拉西坦联合高频重复经颅磁刺激对脑梗死恢复期康复情况的影响研究

目的观察奥拉西坦联合高频重复经颅磁刺激(rTMS)对脑梗死恢复期康复情况的影响。方法选择商丘市中医院2021年10月至2023年4月收治的110例脑梗死患者为研究对象开展前瞻性研究,以计算机随机分组法将其列为联合组(55例)和对照组(55例),对照组实施常规治疗联合rTMS治疗,联合组在对照组的基础上采用奥拉西坦辅助治疗,开展为期6个月随访,比较两组患者的治疗效果及预后情况。结果不同方案治疗后,联合组的核因子E2相关因子2(Nrf2)、血红素氧合酶1(HO-1)、醌氧化还原酶1(NQO-1)蛋白表达水平均高于对照组(P<0.05);联合组的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)均高于对照组,丙二醛(MDA)低于对照组(P<0.05);联合组的脉搏波波速(WV)、脑血管动态阻力(DR)、血管阻力指数(RI)均低于对照组(P<0.05);联合组治疗7 d、14 d后的神经功能缺损量表(NIHSS)评分及改良Rakin量表(mRs)评分均低于对照组;随访期间,联合组的不良事件发生率7.27%(4/55)低于对照组21.82%(12/55),差异具有统计学意义(P<0.05)。结论奥拉西坦联合rTMS能有效改善脑梗死恢复期患者的抗氧化力,并减轻应激损伤,对促进患者脑血流动力学、神经功能康复并改善预后均有积极意义。

益气活血通络汤联合丁苯酞治疗脑梗死恢复期患者的效果

目的:观察益气活血通络汤联合丁苯酞治疗脑梗死恢复期患者的效果。方法:选取2019年2月至2022年2月该院收治的75例脑梗死恢复期患者进行前瞻性研究,按照随机数字表法将其分为研究组38例与对照组37例。对照组采用丁苯酞软胶囊治疗,研究组在对照组基础上联合益气活血通络汤治疗。比较两组临床疗效、治疗前后日常生活能力[Barthel指数(BI)]评分、肢体运动功能[Fugl-Meyer运动功能量表(FMA)]评分、神经功能相关指标[改良Rankin量表(MRS)、中枢神经特异性蛋白(S100β)]水平、脑血流动力学指标[大脑前动脉(ACA)、基底动脉(BA)血流速度]水平及不良反应发生率。结果:研究组治疗总有效率为94.74%(36/38),高于对照组的75.68%(28/37),差异有统计学意义(P<0.05);治疗后,两组BI、FMA评分均高于治疗前,且研究组高于对照组,差异有统计学意义(P<0.05);两组MRS评分和S100β水平均低于治疗前,且研究组低于对照组,差异有统计学意义(P<0.05);两组ACA、BA血流速度均高于治疗前,且研究组高于对照组,差异有统计学意义(P<0.05);两组不良反应发生率比较,差异无统计学意义(P>0.05)。结论:益气活血通络汤联合丁苯酞治疗脑梗死恢复期患者可提高治疗总有效率、BI评分、FMA评分和脑血流动力学指标水平,降低神经功能相关指标水平,其效果优于单纯丁苯酞软胶囊治疗。

认知与行为护理联合精准动态延伸护理在神经内科难治性癫痫患者中的应用研究

目的:探讨认知与行为护理联合精准动态延伸护理在神经内科难治性癫痫患者中的应用研究。方法:选取2021年1月—2022年1月南阳市中心医院收治的102例神经内科难治性癫痫患者作为研究对象,将其随机分为实验组(51例)与常规组(51例)。常规组实施精准动态延伸护理,实验组在常规组的基础上进行认知与行为护理,护理时间均为3个月。对比两组患者护理期间自我效能评价量表(GSES)、癫痫发作次数和护理前后生活质量。结果:护理后,实验组患者GSES评分均高于常规组,差异有统计学意义(t=10.152,P<0.05);实验组患者护理期间癫痫发作次数少于常规组,差异有统计学意义(t=28.346,P<0.001);护理后,实验组患者生活质量评分均高于常规组,差异有统计学意义(t=6.744,P<0.05)。结论:认知与行为护理联合精准动态延伸护理能够改善神经内科难治性癫痫患者自我效能、降低癫痫发作次数,还可提高患者的生活质量。

醒脑通窍汤对脑梗死恢复期患者血液流变学及认知功能的影响

目的探讨醒脑通窍汤对脑梗死恢复期患者血液流变学及认知功能的影响。方法方便选取2021年1月—2022年1月在福建中医药大学附属人民医院脑病科、福建师范大学医院神经内科治疗的72例脑梗死恢复期患者为研究对象,随机分为两组,对照组使用常规西医治疗,观察组在此基础上,加用醒脑通窍汤,疗程共8周,对比两组的临床疗效、血液流变学指标、血小板参数、神经功能缺损指标、认知及运动指标。结果观察组治疗有效率为94.44%(34/36),高于对照组的76.47%(26/36),差异有统计学意义(χ^(2)=6.400,P<0.05);观察组治疗后血浆黏度、全血(高/低)切黏度、红细胞压积、花生四烯酸、二磷酸腺苷均低于对照组,差异有统计学意义(t=6.864、13.081、6.321、5.418、7.640、18.958,P<0.05);观察组治疗后血小板计数、血小板压积高于对照组,平均血小板体积、血小板分布宽度低于对照组,差异有统计学意义(t=2.869、4.243、4.586、2.539,P<0.05);观察组治疗后NHISS评分低于对照组,BI指数、MoCA评分、FMA评分明显高于对照组,差异有统计学意义(t=6.101,4.219、2.282、3.698,P<0.05)。结论醒脑通窍汤对脑梗死恢复期有显著疗效,可改善血液流变学,改善血小板参数,明显减轻神经功能缺损,促进认知、肢体等功能的恢复,提高生活质量。

围术期针对性护理用于合并糖尿病患者神经介入治疗效果评价

目的探讨合并糖尿病(DM)患者神经介入治疗围术期实施针对性护理的临床价值。方法选取医院2021年1月1日至2022年11月30日收治的合并DM且行神经介入治疗患者76例,按随机数字表法分为对照组和观察组,各38例。围术期,两组均予常规护理,观察组加予针对性护理。结果护理后,观察组患者的空腹血糖、餐后2 h血糖水平均明显低于对照组,并发症发生率明显低于对照组,护理满意度明显高于对照组(P<0.05)。结论在合并DM患者的神经介入治疗围术期实施针对性护理,可稳定其血糖水平,减少手术并发症,提升其护理满意度。

吡拉西坦治疗脑出血恢复期患者的效果分析

目的:分析吡拉西坦治疗脑出血恢复期患者的效果。方法:选取2021年10月—2022年10月绵阳市中心医院神经外科收治的100例脑出血恢复期患者作为研究对象,根据随机数字表法分为对照组和观察组,各50例。对照组采用常规治疗,观察组在对照组基础上给予吡拉西坦片治疗。比较两组治疗前后脑血流动力学指标、神经功能缺损状况和认知功能、不良反应发生情况。结果:治疗前,两组血流速度、血流量、外周阻力、临界压力比较,差异无统计学意义(P>0.05);治疗后,观察组血流速度、血流量高于对照组,外周阻力、临界压力低于对照组,差异有统计学意义(P<0.05)。治疗前,两组美国国立卫生研究院卒中量表(NIHSS)、蒙特利尔认知功能评估量表(MoCA)评分比较,差异无统计学意义(P>0.05);治疗后,观察组NIHSS评分低于对照组,MoCA评分高于对照组,差异有统计学意义(P<0.05)。两组不良反应总发生率比较,差异无统计学意义(P>0.05)。结论:吡拉西坦治疗脑出血恢复期患者的效果显著,能够改善脑血流动力学指标,促进神经功能恢复,改善认知功能,且安全性较高,值得临床应用并予以推广。

阿立哌唑治疗育龄期难治性精神分裂症的效果及对泌乳素的影响

目的探讨帕利哌酮联合阿立哌唑治疗育龄期难治性精神分裂症的效果及对泌乳素的影响。方法将80例育龄期难治性精神分裂症患者按照随机数字表法分为研究组和对照组,各40例。对照组患者给予帕利哌酮治疗,研究组患者给予帕利哌酮联合阿立哌唑治疗,两组患者均治疗8周。比较治疗前后两组患者临床症状评分、血清泌乳素水平、蒙特利尔认知评估量表评分、世界卫生组织生存质量测定量表简表评分,并比较两组患者临床疗效、不良反应发生率、治疗依从率、复发率以及再住院率。结果治疗后研究组患者阳性和阴性症状量表总分及各维度评分、血清泌乳素水平、复发率及再住院率低于对照组,治疗依从率、临床总有效率、蒙特利尔认知评估量表评分、世界卫生组织生存质量测定量表简表评分高于对照组(P<0.05或0.01)。两组患者不良反应总发生率没有明显差异(P>0.05)。结论帕利哌酮联合阿立哌唑治疗育龄期难治性精神分裂症,可显著改善病情,有效降低血清泌乳素水平,安全性高,值得推广。

心脏手术后神经系统并发症的评估与管理

卒中、认知功能障碍和谵妄等形式的神经系统损伤是心脏手术后的常见并发症,也是导致心脏手术患者术后死亡和长期致残的主要原因。目前有许多研究尝试确定干预和治疗策略,但尚未形成标准化的神经功能保护方案。本文旨在讨论心脏手术后神经损伤的风险因素、机制和改善患者预后的神经保护措施,阐述近期从术前评估和干预、术中管理和监测,以及术后并发症的诊断和治疗的研究进展,强调围手术期防治重点应以预防缺血缺氧性损伤为主。未来研究方向应侧重于临床前实验的转化研究及新型成像技术的开发,以降低神经系统并发症的发生率,改善预后。

“五联一体”综合康复方案对脑梗死恢复期患者神经功能恢复的影响

目的观察“五联一体”综合康复方案对脑梗死恢复期患者神经功能恢复的影响。方法选取2020年11月—2021年11月观察组(陕西省中医医院)、对照组(陕西中医药大学附属医院)脑梗死恢复期患者120例,每组患者数为60例,两组患者入院后均给予脑血管病内科基础治疗;对照组在基础治疗上,给予常规康复治疗,1次/d,共治疗3个月;观察组在基础治疗上,给予“五联一体”综合方案,1次/d,共治疗3个月。通过比较两组患者治疗前后神经功能缺损评分(NIHSS)、改良Rankin量表、日常生活能力量表(ADL)、Barthel指数(BI)、脑卒中专用生活质量量表(SS-QOL)、中风病证候要素诊断量表的变化,评价“五联一体”综合康复方案对脑梗死恢复期患者神经功能恢复的影响。结果治疗后,观察组NIHSS评分显著低于对照组(P<0.05),Rankin评分显著低于对照组(P<0.05),ADL评分显著低于对照组(P<0.05),Barthel评分显著高于对照组(P<0.05),SS-QOL评分显著高于对照组(P<0.05),证候要素诊断量表评分显著低于对照组(P<0.05)。结论脑梗死恢复期患者采取“五联一体”综合方案进行治疗能够有效提升治疗效果,改善神经功能,提升患者的日常活动能力和生存质量,疗效显著。