Pathological study on right atrium myocardium in rheumatic heart dis-ease patients with atrial fibrillation

Objective: To study the pathological basis of right atrial fibrillation in rheumatic heart disease (RHD) patients with atrial fibrillation (AF). Methods: Twenty-nine patients with mitral valve replacement of RHD were divided into AF group (n=13) and sinus rhythm group (SN group) (n=16). There was no significant statistical difference in clinical factors between the 2 groups. During the operation of valve replace-ment, the samples of right atrial appendages were taken and the qualitative and quantitative study were made by light microscopy and electron microscopy. Results: (1) Light microscope: The interstitial fibrosis and the arrangement of myocardium was more disordered in AF group than that in SN group. However, no statistic difference was found in interstitial fibrosis and cellar hypertrophy degree between the 2 groups. (2) Electron microscope: Mitochondrial crosta broke and dissolved obviously in AF group. The mitochondrial volume in AF group was smaller than that in SN group. Volume density, average area and average perimeter in AF group were less than that in SN group ; specific surface in AF group was bigger than that in SN group. There was significant difference of above factors between the 2 groups; but there was no significant difference of surface density and numerical density on area in the 2 groups. Volume density of myofibril in AF group and SN group were less than that in SN group. (3)Split of Intercalated disc(ID) gap was found in AF group, and there was marrowing and floccular substance in ID gap. Conclusion : There were significant differences in the pathological changes of right atrial myocardium between AF and SN with RHD, these changes may be the im-portant pathological basis for RA fibrillation of AF patients with RHD.     

Long-term efficacy and safety of very-low-dose amiodarone treatment for the maintenance of sinus rhythm in patients with chronic atrial fibrillation after successful direct-current cardioversion

Background Long-term maintenance of sinus rhythm after successful conversion of chronic atrial fibrillation （CAF）, often ameliorates patients＇ symptoms, reduces the risk of ischemic stroke and improves cardiovascular hemodynamics. This prospective study aims to evaluate the long-term efficacy and safety of very low-dose amiodarone （100 mg daily） for the maintenance of sinus rhythm after successful direct-current （DC） cardioversion in patients with CAF and rheumatic heart disease （RHD） post intervention. Methods This study was a randomized prospective trial. One day after successful DC cardioversion （remained normal sinus rhythm） in patients with CAF and RHD post intervention for more than six months and adequate anticoagulation, all were randomly administered either amiodarone 200 mg daily in group A or amiodarone 100 mg dally in group B. Results A total of 76 patients （40 men and 36 women） were examined from February 1998 to December 1999. The mean age of the patients was （664- 10） years, and the mean follow-up was （674-8） months （range 61 to 84 months）. Actuarial rates of the maintenance of sinus rhythm were similar in the two groups after 5 years of follow-up. Four patients （11%） in group A but none in group B experienced significant adverse effects that necessitated withdrawal of amiodarone. No death occurred during the study period. Conclusion A very low dose of amiodarone results in adequate long-term efficacy and is safe for maintaining sinus rhythm in patients with CAF and RHD post intervention after successful DC cardioversion.     

Effects of Minimally Invasive Puncture and Drainage of Intracranial Hematoma on the Blood-brain Barrier in Patients with Cerebral Hemorrhage

The effects of minimally invasive surgery on the blood-brain barrier (BBB) of 30 patients with cerebral hemorrhage were investigated. Difference of the BBB index and serum MBP concentra-tion were assessed in 15 cases of conservative treatment group and 15 cases of minimally invasive surgery group. The BBB index in minimally invasive surgery group was significantly lower than in conservative treatment group (P<0.05), and the BBB index in the two treatment groups was signifi-cantly higher than in control group (P<0.01). Serum MBP concentration in minimally invasive sur-gery group was significantly lower than in conservative treatment group (P<0.05), and that in the two treatment groups was significantly higher than in control group (P<0.01). It was suggested the per-meability of BBB in patients with cerebral hemorrhage was increased, and BBB index and serum MBP concentration in patients with cerebral hemorrhage were increased. Minimally invasive surgery can reduce the lesion of cytotoxicity to BBB and cerebral edema.     

Effect of kidney-reinforcing,blood-activating and stasis-removing recipes on adhesion molecule expression of bone marrow mesenchymal stem cells from chronic aplastic anemia patients

OBJECTIVE:To explore the effect of kidney-reinforcing,blood-activating and stasis-removing recipes on adhesion molecule expression of bone marrow mesenchymal stem cells(MSCs) from patients with chronic aplastic anemia(CAA).METHODS:We used threeTraditional Chinese Medicine recipes,namely a kidney-reinforcing recipe(KRR),blood-activating and stasis-removing recipe(BASRR),and kidney-reinforcing,blood-activating and stasis-removing recipe(KRBASRR),and a normal saline control to prepare herbal medicine serum in Sprague Dawley rats.Thirty CAA patients were enrolled in the experimental group,including 17 kidney-Yang deficient patients and 13 kidney-Yin deficient patients.Ten healthy individuals were included in the control group.MSCs were isolated from bone marrow samples,and the cell density was observed to measure their proliferation ability by microscopy on days 2,7,and 14 after isolation.In addition,the expression of adhesion molecules of bone marrow MSCs(CD106,CD49d,CD31 and CD44) were detected by flow cytometry after 48 h of treatment with the four different herbal medicine serums.RESULTS:The proliferation of MSCs from kidney-Yang deficient and kidney-Yin deficient patients was weaker than that of MSCs from the control group.The expression of all adhesion molecules of bone marrow MSCs from CAA patients was obviously lower than that in the control group(P< 0.01).The expression of CD49d and CD31 in MSCs from patients with a kidney-Yin deficiency was lower than in those with a kidney-yang deficiency(P< 0.05 and P<0.01,respectively).For kidney-Yang deficient patients,CD31 expression in the KRBASRR group was significantly higher than that in the BASRR group(P<0.01),while CD44 in the KRBASRR group was significantly higher than that in both KRR and BASRR groups(P<0.01).For kidney-Yin deficient patients,CD106 and CD49d expression in the KRBASRR group was obviously higher than that in the KRR group(P<0.05),while CD31 and CD44 expression in the KRBASRR group was significantly higher than that in both KRR and BASRR groups(P< 0.05 and P<0.01,respectively).CONCLUSION:The bone marrow microenvironment in CAA patients is abnormal.The effect of KRBASRR may be better than that of KRR and BASRR for kidney-Yang deficient and kidney-Yin deficient patients by improving the expression levels of MSC adhesion molecules.     

Relationship of anxiety state with lymphocyte subsets and the effect of chinese medical treatment on anxiety in patients with chronic hepatitis B

Objective:To analyze the relationship of anxiety state with CD4~+ level and CD4~+/CD8~+ ratio and to observe the effect of Chinese medicine(CM) treatment on anxiety in chronic hepatitis B(CHB) patients. Methods:The anxiety state of 120 CHB patients was evaluated based on Hamilton Anxiety Scale(HAMA) scoring.According to the scores,63 patients with scores≥14 were classified to anxiety and 57 patients with scores<14 to non-anxiety.The differences in CD4~+ cells and CD4~+/CD8~+ ratio between patients with anxiety and non-anxiety were analyzed.Moreover,63 patients with anxiety were randomized into two groups:31 in the control group were treated with lamivudine(100 mg per day) alone and 32 in the observation group were given equal dosage lamivudine combined with CM treatment depending on syndrome differentiation,all for 12 weeks. The effects of treatment on anxiety state and T-lymphocyte subsets as well as its impact on some CHB-related indices were observed and compared.Results:The anxiety state of CHB patients was negatively correlated with CD4~+ and CD4~+/CD8~+;the level of CD4~+ in patients with anxiety was significantly lower than that in non-anxiety patients(P<0.01 or P<0.05).After treatment,anxiety state in the observation group was significantly improved, with their HAMA scores significantly lowered(P<0.01),and the levels of CD4~+ and CD4~+/CD8~+ were significantly higher than those in the control group(P<0.05 or P<0.01).Moreover,the alanine transaminase recovery rate and the HBV-DNA-negative conversion rate in the observation group were significantly higher than those in the control group,respectively(P<0.05).Conclusions:The anxiety state of CHB patients was related to CD4~+ and CD4~+/CD8~+ levels.CM treatment could improve the anxiety state and showed certain regulatory effect on the patients’ immune system.     

Mechanisms of organized atrial tachycardia during catheter ablation of chronic atrial fibrillation by stepwise approach

Background Extensive atrial fibrillation （AF） ablation is associated with an increased success rate of catheter ablation in chronic AF patients and an increased rate of atrial tachycardia （AT） during the procedure. The mechanism of these Ats varies in previous studies. Our study aimed to report the mechanism of organized AT occurring during the stepwise ablation procedure of chronic AF.Methods A prospective cohort of 86 consecutive patients who underwent an ablation procedure for chronic atrial fibrillation （CAF） was investigated. The stepwise procedure was performed in the following order： circumferential pulmonary vein ablation, complex fractionated atrial electrograms ablation, mapping and ablation of AT. The endpoint was noninducibility of AF/AT after sinus rhythm （SR） was restored or the procedure time was beyond 6 hours.Results Sixty-nine （80%） of patients converted to SR via AT. A total of 179 sustained ATs were observed in 69 patients during the procedure. There were 81% （n=145） macroreentrant ATs which included 65 perimitral circuits, 48 peritricuspid tachycardia and 32 roof dependent circuits, 12% （n=21） localized reentrant and 7% （n=13） focal ATs. Thirty （15%） patients experienced significant left atrium （LA） and LA appendage （LAA） conduction delay or dissociation in the procedure or during the follow-up period.Conclusions Most CAF patients converted to SR via ablation of organized AT occurring during the stepwise procedure. The mechanism of most of these ATs was macro-reentry.     

Acidic HEPES-KH Reperfusion Enhances Myocardial Protection in Immature Rabbits

Summary: To study the effects of different pH HEPES-KH reperfusate solution on immature myocardial protection, isolated perfused Langendorff model from immature rabbit hearts were developed formed. Control group (C) was perfused only with pH 7. 4 HEPES-KH solution for 90 min. Is chemia/reperfusion group (group I/R) was perfused with pH 7. 4 HEPES-KH solution before is chemia or after ischemia. Experimental group (group E), after ischemia, was perfused with pH 6.8,pH 7. 1 and pH7.4 HEPES-KH solutions for 5 min, 5 min, and 20 min, respectively. The left ven tricular function recovery, MWC, LDH and CK leakage, MDA, ATP content, and SOD activity were determined. Our results showed that the left ventricular function recovery, ATP content and SOD activity in group E were higher than those of group I/R (P＜0. 05). MWC, MDA content,LDH and CK leakage in group E were lower than those of group I/R (P＜0. 05). These findings suggested that pH paradox might be one of important mechanisms for immature myocardial ischemia reperfusion injury, and acidic perfusate, at the beginning of reperfusion, might attenuate pH paradox and ameliorate functional recovery in isolated perfused immature rabbit hearts.     

Clinical study of acoustic densitometry technique in detecting atherosclerotic plaque

Objective: To investigate the effect of Quyu Xiaoban Capsule (祛瘀消斑, QYXB) on the regressive treatment of atherosclerosis (AS) with acoustic densitometry (AD) technique. Methods: Eighty patients with AS were randomly divided into two groups, trial group was treated with QYXB and conventional medicine, and control group was treated with conventional medicine alone. Normal arterial wall and different types of atherosclerotic plaques were detected with AD technique before treatment and 10 months later. Resuits: The corrected averages in intimal echo intensity (AIIc%) were elevated in both groups but without significant difference, AIIc% of fatty plaques were increased in both groups and the value after treatment was significantly higher than that of pre-treatment in the trial group (68.12±5.54 vs 61.43±5.37, P＜0.05).The increment rate of AIIc% in trial group was significantly higher than that in control group (10.9±5.1% vs2.5±5.5%, P＜0.05). Conclusion: QYXB can stabilize the atherosclerotic plaque by increasing its acoustic density. Acoustic densitometry technique can differentiate the different histological plaques and monitor the histological changes of plaques during treatment.     

Metabolic syndrome in patients with atrial fibrillation in the absence of structural heart disease from a tertiary hospital in China

Background Metabolic syndrome （MetS） and atrial fibrillation （AF） are causally related. This study aimed to determine the prevalence of MetS in patients with AF in the absence of structural heart disease from a tertiary hospital in China.
Methods In a single center, 741 inpatients with AF in the absence of structural heart disease prior to catheter ablation were retrospectively reviewed. Among them, 588 （79.4%） patients had paroxysmal AF. Subgroup analyses were performed in paroxysmal AF and persistent/permanent AF.
Results MetS was found in 343 （46.3%） patients （200 males, 143 females）; 0, 1, 2, 3, 4, 5 components of the MetS were found in 59 （8.0%）, 140 （18.9%）, 199 （26.9%）, 203 （27.4%）, 103 （13.9%） and 37 （5.0%） patients, respectively. The prevalences of overweight/obesity, high blood pressure, high glucose level, high triglyceride level and low high density lipoproteins cholesterol level were 53.8%, 47.6%, 23.2%, 40.6% and 72.1%, respectively. The prevalence of MetS was not significantly different between the paroxysmal AF group and the persistent/permanent AF group （44.6% vs 52.9%, P=0.064）. The five components of MetS except overweight/obesity （69.3% vs 49.8%, P 〈0.001） were not significantly different between the aforementioned two groups. The left atrium diameter increased with the sum of the MetS components. The left atrium diameter in the MetS group was significantly higher than that in the non-MetS group both in patients with paroxysmal AF and in patients with persistent/permanent AF.
Conclusions The prevalence of MetS in patients with AF prior to catheter ablation is high. Further study and prevention are needed.     

风湿性心脏瓣膜病患者钾离子通道特性变化的实验研究

目的:探讨风湿性心脏瓣膜病(简称风心病)患者心房组织细胞Kvl.5钾通道的变化。方法:将风心病患者分为窦性心律组(SR)、阵发性房颤组(PAF)和慢性房颤组(CAF)。应用全细胞膜片钳技术记录各组单个右心耳组织细胞超快速延迟整流钾电流(ultrarapid delayed rectifier current,IKur)的表达。结果:指令电压为+10~+50mV时,慢性房颤组(n=22)IKur密度较窦性心律组(n=25)明显降低。阵发性房颤组(n=23)IKur密度与窦性心律组差异无统计学意义(P>0.05);其中,在+50mV时,电流由窦性心律组(8.98+1.69)PA/pF降为房颤组的(4.17+1.82)PA/pF(P<0.01),降低幅度为(53.6+1.4)%。阵发性房颤组(8.21+1.54)PA/pF与窦性心律组差异无统计学意义(P>0.05),与慢性房颤组差异有统计学意义(P<0.01)。结论:Ikur密度在发生慢性房颤的风心患者心房肌细胞中密度明显下降,提示Kv1.5钾通道的变化与风心病房颤的发生有关。     

慢性房颤对风湿性心脏病心房肌细胞ELK-1、p-ELK-1表达的影响

目的 研究风湿性心脏病慢性房颤患者心房肌细胞ELK-1、p-ELK-1的表达,探讨房颤发生与ELK-1、p-ELK-1 表达之间的关系.方法 12例风心病换瓣患者分为2组:①慢性房颤组(6例)房颤持续时间均＞6个月,②窦性心律组(6例)为正常心律.手术中切取少许右心房游离壁组织采用免疫组化和间接免疫荧光技术检测心房肌ELK-1、p-ELK-1的表达与分布.结果 ①免疫组化显示ELK-1主要表达在心房肌细胞质和细胞核,慢性房颤心房肌较窦性心律心房肌表达明显减弱;②间接免疫荧光技术显示ELK-1在窦性心律心房肌细胞核表达相对较高,在房颤心房肌细胞核中表达明显受到抑制;p-ELK-1在房颤心房肌、窦性心律心房肌均表达受抑.结论 转录激活因子ELK-1的表达改变可能在慢性房颤心房肌的分子重构中起着重要的作用.     

慢性心房颤动患者心房肌细胞Kir2.1、Kir3.4和Kv4.3钾通道重构的研究

目的:观察心房颤动(AF)患者心房组织钾通道 IK,ACh、IK1及 Ito1基因水平的改变。方法:将 59 例风湿性心瓣膜病接受心脏外科手术患者分为两组,其中窦性心律(SR)患者 29 例,慢性房颤(CAF)患者 30 例。手术时切取患者右心耳组织,应用RT PCR技术检测心房肌组织 Kir2.1、Kir3.4 和 Kv4.3 mRNA的表达。结果:与 SR组相比,Kir2.1 mRNA的表达在CAF患者中增加明显,达71%(P<0.01),并与 AF时程呈明显正相关(r=0.49,P=0.004)。与之相反的是Kir3.4 mRNA的表达在CAF患者中均显著减少(下降43%,P<0.01),与AF时程呈明显负相关(r=-0.54, P=0.003)。CAF组编码 Ito1的Kv4.3钾通道的mRNA表达较SR组明显下降(下降 60%,P<0.01)。Kv4.3 mRNA表达也与AF时程呈明显负相关(r=-0.67,P=0.003)。结论:慢性房颤患者 Kir2.1的mRNA表达水平增加及Kir3.4和Kv4.3 的mRNA表达水平减少可能分别是 IK1上调、IK,ACh和 Ito1下调的分子基础,而Kir3.4和Kv4.3 mRNA表达水平减少很可能是机体为拮抗AF电重构时有效不应期缩短的代偿机制之一。     

ACEI对风湿性心脏病心房颤动患者心房ACE、ERK表达和纤维化改变的影响

目的:研究风湿性心脏病(风心病)心房颤动(房颤,AF)患者用血管紧张素转换酶抑制剂(ACEI)时心房组织血管紧张素转换酶(ACE)、细胞外信号调节激酶(ERK)表达与心房纤维化改变.方法:35例风心病二尖瓣狭窄接受外科手术患者,手术时取右心耳处心房组织400mg,通过逆转录-聚合酶链反应技术,以GAPDH为内参照,测量ACE,ERK2 mRNA变化,用Western Blotting观察ACE、磷酸化ERK(pERK)在蛋白水平表达的差异,经Masson染色研究胶原纤维容积分数(CVF)改变情况.结果:与窦性节律患者比较,慢性房颤患者在mRNA水平上ACE、ERK2表达上调,在蛋白水平上ACE、pERK表达上调(P＜0.01或P＜0.05),CVF也显著增加(P＜0.01);与未应用ACEI组比较,用ACEI组ERK2 mRNA、pERK蛋白表达下调(P＜0.05),ACE表达无差异,CVF虽有减少趋势,但无统计学意义(P＞0.05).结论:风心病慢性房颤患者较窦性节律患者ACE、ERK表达增加,纤维化加重;而在应用ACEI的慢性房颤患者,ERK2,pERK表达有显著下降,纤维化减轻,说明在房颤时,局部激活的肾素-血管紧张素系统(RAS)经ERK途径介导了心房纤维化,ACEI在一定程度上减轻心房的纤维化.     

风湿性心脏病二尖瓣狭窄心房颤动与窦性心律心肌细胞起搏电流密度的差异

目的运用全细胞膜片钳技术,研究风湿性心脏病二尖瓣狭窄心房颤动(简称房颤)与窦性心律(简称窦律)心肌细胞起搏电流(If)的差异。方法急性分离人心肌细胞,将其分为风湿性心脏病二尖瓣狭窄房颤(atrial fibrillation,AF)组和窦律(sinus rhythm,SR)组,记录两组的If,观察两组心肌细胞If的差别。结果 AF组心肌细胞的If密度明显大于SR组,在-140～-40 mV,AF组和SR组电流密度的差异有统计学意义(P<0.01);其中,在-70 mV时,AF组与SR组If的电流密度分别为(-42.98±2.77)与(-26.93±1.08)pA/pF,此时两组电流密度差异最大。结论 AF心肌细胞的If密度较SR心肌细胞增大,提示If增大可能导致AF,可能是风湿性心脏病二尖瓣狭窄房颤发生的机制之一。     

风心病慢性房颤心房连接蛋白表达与AERP的相关性研究

目的:通过检测风心病慢性房颤患者左、右心房缝隙连接蛋白Cx40和Cx43表达及相应部位的心房有效不应期(AERP)研究两者之间的相关性,探讨Cx40和Cx43对慢性房颤左、右心房电生理特性的影响. 方法:29例风心病伴或不伴慢性房颤的患者,共分2组:窦性心律组(SR组,n=13),慢性房颤组(CAF组,n=16),另取6例非风心病作为正常对照组.在行二尖瓣置换术时,采用心外膜标测技术测定左、右心房的AERP,并在相应部位切取心房组织,通过Western印迹法检测左、右心房肌Cx40和Cx43的表达,同时对两者行相关性分析. 结果:CAF组患者左、右心房Cx40的表达和AERP较SR组有明显下降(P<0.05),而Cx43无明显变化;左心房后壁Cx40的相对表达量与AERP呈明显正相关(r＝0.762,P<0.01),而Cx43与AERP无明显相关.SR组中,Cx40和Cx43均与AERP无明显相关.结论:在风心病慢性房颤心房中,Cx40表达下调参与慢性房颤的心房重构,并影响心房的电生理特性,提示Cx40的表达对风心病慢性房颤的发生和维持具有重要的作用.     

人心肌细胞的分离方法和充血性心力衰竭患者心房肌细胞钾电流的特征

目的：探索人类心房肌细胞的分离方法及充血性心力衰竭（CHF）患者心房肌细胞延迟整流钾电流（Ik）和内向整流钾电流（Ik1）的特征。方法：酶法分离心肌细胞；全细胞膜征钳法记录电流。结果：两种酶学分离方法均能成功地分离出合格的心肌细胞。其中，用I型胶原酶和蛋白酶分离出的活细胞的比例约为40%-50%，而且理想的细胞较多；而用V型胶原酶则仅能分离出1%-3%的活细胞。细胞分离过程受消化酶的类型、季节、病种、心功能等多种因素的影响。以上任一因素发生变化，分离细胞的质和量均会发生改变。利用掌握的全细胞膜片钳技术，我们对人心肌细胞上的钾电流进行了探索。结果显示，在充血性心衰患者心房肌细胞上，存在着Ik和Ik1。其中，Ik的激活较慢，其电流轨迹在刺激开始后缓慢上升，至刺激中止前达到顶点。复极至-30mV时，可引导出Ik的尾电流。与时间依赖性电流相比，此电流的幅值较小。与Ik相比，Ik1的激活较快，激活后迅即趋于稳态，不失活。当膜电位处于不同的电位水平时，Ik1分别表现为内向电流和外向电流，并且随着膜电位的增大，内向电流逐渐减小，外向电流则越来越大。结论：人心肌细胞的分离过程受多种因素的影响。对于CHF患者而言，其心房肌细胞上存在着Ik和Ik1，这两种电流具有不同的电生理特征。     

血浆CST在房颤患者中的检测意义

目的:探析不同心房颤动(简称房颤)患者中血浆儿茶酚抑素(CST)表达水平的变化以及其临床价值.方法:分析2014年4月~2015年5月在我院78例急诊和门诊就诊以及心内科住院的房颤患者的临床资料,并将房颤患者分为慢性房颤组(CAF组,21例)和阵发性房颤组(PAF组,57例)两组.根据检测CST水平时房颤发作情况把房颤者分成房颤发作组(50例)和房颤转复后组(28例).另外选取我院同期收治的无房颤病史、合并疾病无明显差异的43例窦性心律患者作为本次研究的对照组.比较房颤组和对照组的一般资料、实验室和超声心动图检查指标和各组患者的血浆CST水平.结果:房颤组患者的心率比对照组快,而就诊时的收缩压及左室射血分数(LVEF)比对照组低,左房前后径(LAD)比对照组大,N末端脑钠肽前体(NT-proBNP)偏高,均有统计学差异.两组患者的性别、年龄、服药情况等无明显差异.房颤组患者的血浆CST水平明显比对照组低;PAF组、CAF组血浆CST水平均明显低于对照组;与PAF组相比,CAF组患者有下降趋势;房颤发作组、转复后组的血浆CST水平均明显低于对照组,但是转复后组和房颤发作组间无明显差异.结论:房颤的维持及发生均与血浆CST水平相关;CST水平的下降是引发房颤的一个潜在的独立预测因子.     

乳酸左氧氟沙星对豚鼠心肌细胞延迟整流钾电流的影响

目的:观察氟喹诺酮类药物左氧氟沙星(levofloxacin,LVFX)对豚鼠心肌细胞延迟整流钾电流(IK)的影响。方法:采用酶消化的方法分离出单个豚鼠心室肌细胞,利用全细胞膜片钳技术记录不同浓度的LVFX对豚鼠心室肌细胞IK的影响。结果:①SPX和LVFX浓度依赖地抑制IK的脉冲电流和尾电流,但不影响其原有的电压和时间依赖性。②当LVFX作用浓度分别为0.1,1,10,100,1000μM时,在+50 mV去极化电压下,测得IK的脉冲电流较对照组依次减少了(11.81±1.71)%,(14.51±2.12)%,(22.78±3.58)%,(29.59±2.89)%,(38.13±2.44)%;尾电流依次减少了(6.05±251)%,(12.19±1.49)%,(17.75±2.74)%,(30.05±1.49)%,(48.18±3.71)%。结论:LVFX在不同的浓度下对豚鼠心肌细胞的IK有不同程度的抑制。