Antiarrhythmic effects of desethylamiodarone in dogs with subacute myocardial infarction and inducible ventricular arrhythmias

To determine if desethylamiodarone (DA), the principal metabolite of amiodarone, has antiarrhythmic activity, DA was administered intravenously (i.v.) as a 5 mg/kg bolus followed by a 2-h infusion of 8 mg/kg/h to 12 dogs with 5-7-day-old myocardial infarction and reproducibly inducible sustained ventricular arrhythmias. Programmed electrical stimulation of the right ventricle was repeated, and plasma DA concentration was determined at 15-min intervals during DA administration. At the end of the infusion, the animals were killed and DA concentration in infarcted and noninfarcted myocardium was measured. Grading and statistical analysis of induced arrhythmias revealed significant amelioration during DA infusion, with partial or complete suppression in 9 of the 12 dogs. Apparent steady-state plasma DA concentration (range 0.8-1.0 micrograms/ml) was achieved and maintained during the final 105 min of infusion. DA concentration in noninfarcted myocardium (62.6 +/- 22.0 micrograms/g) was significantly higher (p less than 0.01) than DA concentration in infarcted myocardium (25.6 +/- 18.6 micrograms/g). We conclude that DA administered i.v. has antiarrhythmic activity in dogs with subacute myocardial infarction and reproducibly inducible sustained ventricular arrhythmias.     

胺碘酮治疗急性心肌梗死合并室性心律失常的效果研究

目的探讨胺碘酮治疗急性心肌梗死合并室性心律失常的临床疗效。方法急性心肌梗死合并室性心律失常患者86例随机分为治疗组46例和对照组40例,治疗组出现室性心律失常后给予胺碘酮治疗,对照组出现室性心律失常后给予利多卡因治疗,比较2组临床疗效、再住院率及不良反应发生率。结果药物治疗后,治疗组起效时间短于对照组,有效率高于对照组,不良反应发生率及1年内再住院率低于对照组,差异均有统计学意义(P<0.05)。结论胺碘酮治疗室性心律失常,安全有效,值得临床推广。     

胺碘酮治疗急性心肌梗死后室性心律失常的临床分析

目的 分析在急性心肌梗死后室性心律失常患者的临床治疗中胺碘酮的临床应用效果.方法 选取2015年1月至2016年1月本院收治的60例急性心肌梗死后室性心律失常患者为研究对象,将所选患者随机均分为对照组和实验组,对照组患者接受利多卡因常规治疗,实验组患者接受胺碘酮治疗.对比两组患者的临床治疗效果及不良反应情况.结果 实验组患者的临床治疗效果明显好于对照组,且不良反应例数少于对照组,两组患者的数据经对比存在统计学差异(P＜0.05).结论 在急性心肌梗死后室性心律失常患者的治疗中,胺碘酮的临床疗效较好,值得推广.     

胺碘酮与利多卡因治疗急性心肌梗死伴持续性室性心动过速的疗效观察

目的探讨胺碘酮与利多卡因治疗急性心肌梗死(AMI)伴持续性室性心动过速(室速)的临床效果。方法回顾性分析AMI伴持续性室速患者的临床资料,分为胺碘酮组和利多卡因组,评估两种药物抗心律失常的效果。结果胺碘酮组总有效率为87.09%,利多卡因组为54.54%,两组比较,差异有统计学意义(P<0.05)。而两组短期不良反应比较,差异无统计学意义。结论胺碘酮治疗AMI伴持续性室速的临床效果好,安全性高,值得推广应用。     

酒石酸美托洛尔联用小剂量胺碘酮治疗心肌梗死后室性心律失常的比较研究

目的 探讨酒石酸美托洛尔与小剂量胺碘酮联合治疗心肌梗死后室性心律失常的有效性和成功率.方法 回顾性分析本院收治的150例心肌梗死后室性心律失常患者的临床诊治资料,根据治疗方法分为对照组和联合组,其中对照组72例采用酒石酸美托洛尔单一治疗方案,联合组78例采用小剂量胺碘酮联合酒石酸美托洛尔治疗,对比两组治疗后的各项心脏参数、效果及不良反应发生情况.结果 联合组患者的心率、LVEF％、P-R间期及QRS间期均较对照组平稳,两组差异有统计学意义（P＜0.05）;联合组治疗总有效率为97.44％,对照组为86.11％,差异有统计学意义（P＜0.05）;两组患者治疗后总不良反应发生率差异无统计学意义（P＞0.05）.结论 酒石酸美托洛尔联合胺碘酮治疗心肌梗死后室性心律失常,安全性好,临床效价比较高.     

Antiarrhythmic effect of acute and chronic amiodarone treatment in conscious rats

The effect of amiodarone after acute and chronic pretreatment was studied in the early phase of arrhythmias induced by coronary artery ligation in conscious rats. Both acute and chronic amiodarone pretreatments improved survival during the first 20 min after coronary ligation. Only chronic amiodarone pretreatment reduced significantly the incidence of ventricular fibrillation. It was concluded that chronic amiodarone pretreatment seemed to be more effective than the acute one.     

Antiarrhythmic effect of oxprenolol on halothane-epinephrine and coronary ligation induced ventricular arrhythmias in beagle dogs.

Antiarrhythmic effects of oxprenolol, a beta-blocker, were studied quantitatively on arhythmias produced by epinephrine during halothane anesthesia and by two-stage coronary ligation, and were compared to those of other beta-blockers, propranolol and K? 1400, which have been already reported. Though oxprenolol has potent beta-blocking activity, the antiarrhythmic effect on halothane-epinephrine arrhythmia was significantly weaker than those of propranolol and K? 1400. The effective dose of oxprenolol was 60 +/- 18 microgram/kg (mean +/- S.E., N = 6), which is in the range of the so-called beta-adrenergic blocking dose. The weaker antiarrhythmic effect of oxprenolol as compared to propranolol and K? 1400 is probably due to the intrinsic positive chronotropic effect, which is most clearly observed in oxprenolol as compared to the other two drugs. As for two-stage coronary ligation arrhythmia, oxprenolol suppressed only that observed 48 hours after coronary ligation using higher doses (5 to 10 mg/kg). Other beta-blockers also showed similar effects. Because of the high doses necessary for the antiarrhythmic effects on the coronary ligation arrhythmia, the mechanism for suppressing the arrhythmia is probably due to the local anesthetic action of the beta-blockers.     

Effects of bradykinin on inducible sustained ventricular tachycardia two weeks after myocardial infarction in pigs.

We studied the in vivo effect of bradykinin infusion on inducible sustained ventricular tachycardia (VT) 2 weeks after myocardial infarction in pigs, based on the assumption that the antiarrhythmic effect of angiotensin-converting enzyme (ACE) inhibitors may, apart from their angiotensin-II lowering effect, also be due to elevation of endogenous bradykinin levels. Of the six pigs with inducible VT in the control state, four were noninducible during subsequent bradykinin infusion (p less than 0.05). The ventricular effective refractory period (VERP) did not change during bradykinin infusion (from 237 +/- 37 to 239 +/- 42 ms), nor did intraventricular conduction change (filtered QRS duration was 45 +/- 17 ms before and 43 +/- 19 ms during infusion). Bradykinin caused both a significant systolic blood pressure (SBP) decrease (from 79 +/- 14 to 49 +/- 4 mm Hg, p less than 0.001) and diastolic BP (DBP) decrease (from 41 +/- 10 to 27 +/- 4 mm Hg, p less than 0.01). In conclusion, exogenous bradykinin reduced the inducibility of sustained VT 2 weeks after myocardial infarction. Because refractory periods or conduction velocity were not affected, the mechanism of action might be associated with the BP decrease, which can decrease wall stress. The previously reported antiarrhythmic effect of ACE inhibitors may be due in part to elevation of endogenous bradykinin levels.     

Antiarrhythmic effect of aprindine on several types of ventricular arrhythmias.

The antiarrhythmic effect of aprindine was compared with those of lidocaine and propranolol on several ventricular arrhythmias-epinephrine arrhythmias in cats, ouabain arrhythmias in cats and guinea pigs, ischemic ventricular arrhythmias in coronary-ligated Beagle dogs. Antiarrhythmic effects of aprindine and lidocaine were observed both in ouagain and ischemic arrhythmias, but not in epinephrine arrhythmias. While propranolol had a strong antiarrhythmic effect against epinephrine and ouabain arrhythmias, it did not increase sinus beats in ischemic arrhythmias. Marked anti-arrhythmic effects of aprindine in ischemic arrhythmias were observed in dogs using either single intravenous administration (4 mg/kg) or intravenous infusion (200 mug/kg/min, 2 mg/kg). Antiarrhythmic activity of aprindine is considered to be about twice as strong as that of lidocaine, but lidocaine is less toxic in experimental animals.     

Plasma beta-thromboglobulin in acute myocardial infarction with ventricular arrhythmias

Patients with myocardial infarction, complicated by ventricular arrhythmias (Lown grade greater than or equal to 2), had higher (p less than 0.05) plasma beta-thromboglobulin level than that found in patients with uncomplicated infarction. This indicates higher platelet activation in the former group than in the latter. Such data provide rationale for clinical trial of antiplatelet drugs in cases of myocardial infarction complicated by severe arrhythmias.     

美托洛尔联合胺碘酮治疗慢性心力衰竭并室性心律失常疗效分析

目的探讨胺碘酮和美托洛尔联合治疗充血性心力衰竭(CHF)合并室性心律失常的疗效及安全性。方法将30例CHF伴室性心律失常的患者随机分为胺碘酮联合美托洛尔组(治疗组)15例与美托洛尔组(对照组)15例,观察两组心律失常好转情况及心功能改善情况。结果治疗组心功能及室性心律失常的治疗有效率明显高于对照组,两组比较有显著性差异(P<0.05)。治疗后两组左心室射血分数(LVEF)、LVEDV、LVESV和6min步行试验均明显改善,治疗组优于对照组,均有显著性差异(P<0.05)。结论胺碘酮和美托洛尔联合治疗充血性心力衰竭合并室性心律失常治疗疗效较好,使用安全。无明显不良反应,值得临床借鉴。     

陈旧性心肌梗死患者心室晚电位检测及其与室性心律失常发生的关系

探讨陈旧性心肌梗死患者心室晚电位的检出率及其与室心律失常发生的关系。方法：对１８５例陈旧性心肌梗死患者、２２５例无心肌梗死的冠心病患者以及７２例正常对照组分别进行心室晚电位检测。结果：心肌梗死组ＶＬＰ阳性率明显高于冠心病组及正常对照组;无心肌梗死的冠心病患者ＶＬＰ阳性率高于正常对照组,但差异无统计学意义。     

门冬氨酸钾镁联合胺碘酮治疗慢性心力衰竭并室性心律失常疗效分析

目的评价门冬氨酸钾镁与胺碘酮联合治疗慢性心力衰竭并室性心律失常的临床疗效。方法选择在该院住院的慢性心力衰竭并室性心律失常患者105例,随机分为治疗组（n=53）和对照组（n=52）。对照组单用胺碘酮,治疗组在对照组的基础上加用门冬氨酸钾镁。观察两组治疗前后的临床效果和不良反应。结果用药4周后,治疗组总有效率为90．57％,对照组为73．08％,两组比较差异有显著性（P〈0．05））。两组治疗前后各项检测指标比较,治疗组显著优于对照组。不良反应率发生率治疗组为7。5％,对照组为23．08％,两组比较差异有显著性（P〈0．05）。结论门冬氨酸钾镁联合胺碘酮治疗慢性心力衰竭并室性心律失常,临床疗效好,不良反应少。     

美托洛尔联合胺碘酮治疗慢性心力衰竭并室性心律失常的疗效分析

目的评价美托洛尔联合胺碘酮治疗慢性心力衰竭并室性心律失常的临床疗效。方法选择吴江市第一人民医院2008年2月至2011年5月收治的慢性心力衰竭并室性心律失常患者50例,按自愿的原则将50例患者分为联合用药组30例和对照组20例,对照组采用胺碘酮,联合用药组在对照组治疗的基础上联合应用美托洛尔治疗。结果两组患者经治疗后对照组心功能改善总有效率为83.3%,联合用药组为65.0%。两组比较差异有显著性(P<0.05)。对照组室性心律失常改善情况总有效率为90.0%,联合用药组为75.0%。两组比较差异有显著性(P<0.05)。两组治疗前后各项检测指标比较联合用药组显著优于对照组。结论胺碘酮和美托洛尔联合治疗慢性心力衰竭合并室性心律失常临床疗效好,在降低室性心律失常、改善心功能等方面优于单用胺碘酮组,且不良反应发生率无明显增加。     

Efficacy of verapamil against ventricular arrhythmias induced by programmed electrical stimulation in the late myocardial infarction phase in dogs.

The aim of the present study was to investigate the antiarrhythmic potential of verapamil in the late myocardial infarction period in conscious dogs. Verapamil was administered in cumulative doses (0.3 + 0.3 mg kg-1). The drug significantly lowered systolic and diastolic blood pressure after both doses. ECG signals showed short-lasting significant decrease in RR and QT intervals together with an increase in QTc interval. The parameters of the atrioventricular conduction system (PQ interval, 2:1 AV-conduction point) were significantly prolonged over the entire observation period. Ventricular effective refractory periods remained unaltered. In contrast to results obtained during acute ischaemia and in the first week thereafter, the present study demonstrates that verapamil moderately increases intraventricular conduction time 14 days after acute myocardial infarction. Verapamil prevented the induction of arrhythmias by programmed electrical stimulation (PES) in only 11% of all induction attempts. The lack of lengthening of refractory periods in the presence of a prolongation of intraventricular conduction time may be responsible for the poor antiarrhythmic efficacy. We conclude that verapamil is only of negligible value for the management of PES-induced ventricular arrhythmias in the late myocardial infarction period.     

Effects of angiotensin II and captopril on inducible sustained ventricular tachycardia two weeks after myocardial infarction in the pig

The effects of angiotensin II (AII) and captopril (C) on the inducibility of ventricular tachyarrhythmias were investigated 14 days after infarction in pigs. In 27 pigs, ischemia was induced by 60-min occlusion of the left coronary artery. Four pigs died of ventricular fibrillation during ischemia, and six others died within 24 h due to pump failure. Of the 17 survivors, eight pigs developed a sustained (greater than 30 s) monomorphic ventricular tachycardia (sVT) after programmed electrical stimulation. In nine noninducible pigs, an AII infusion (0.6 microgram/kg/min) caused inducible sVT in three animals and nonsustained VT in two animals (greater than 10 reentrant beats). In two of the remaining four animals, spontaneous premature ventricular beats appeared during the infusion. In a group of five healthy pigs, the electrophysiological effects of AII were evaluated. Infusion of AII caused a rapid and sustained increase in arterial blood pressure to 161 +/- 6.4% (p less than 0.001). The sinus cycle length decreased to 74 +/- 5.2% (p less than 0.02). The effective refractory period of the right ventricle decreased significantly to 82 +/- 5.5% (p less than 0.05). These results show that modulation of the renin-angiotensin system after myocardial infarction influences the inducibility of malignant ventricular tachyarrhythmias, as shown by the increased inducibility of sustained ventricular tachycardia. This may be related to a decreased ventricular refractoriness. Therefore, it is suggested that C can reduce malignant ventricular tachycardia late after myocardial infarction by preventing the deleterious arrhythmogenic effects of AII.     

胺碘酮在急性心肌梗死并发室性心律失常中的临床应用

目的探讨静脉应用胺碘酮在急性心肌梗死（AMI）并发室性心律失常中的疗效。方法随机将98例发生急性心肌梗死并发室性心律失常住院患者分成两组,两组患者均在积极治疗AMI的基础上抗心律失常治疗,治疗组胺碘酮组（48例）静脉应用胺碘酮,对照组（50例）静脉应用利多卡因。比较两组患者的临床疗效、不良反应。结果治疗组有效41例（85．4％）,死亡4例（8．3％）。不良反应6例（12．5％）;对照组有效33例（66．0％）,死亡13例（26．0％）,不良反应15例（30．0％）。两组间比较差异有统计学意义（P〈0．05）。结论静脉应用胺碘酮是治疗急性心肌梗死并发室性心律失常的有效方法,疗效显著,不良反应少,临床应用安全。     

Effect of ajmaline on sustained ventricular tachycardia induced by programmed electrical stimulation in conscious dogs after myocardial infarction

Summary As yet the antiarrhythmic efficacy of ajmaline with regard to suppressing the induction of sustained ventricular tachycardia after myocardial infarction has not been determined. Therefore, programmed electrical stimulation was performed in 8 conscious, chronically instrumented mongrel dogs 8–20 days after a 4-hour occlusion of the left anterior descending coronary artery. At baseline all animals responded with sustained ventricular tachycardia. Thereafter, ajmaline was administered at two consecutive ix. doses: a bolus of 0.7 mg kg^–1 followed by infusion of 2 mg kg^–1 h^–1 and infusion of 4 mg kg^–1 h^–1. The induction of sustained ventricular tachycardia was prevented in 2/8 animals by 2 mg kg^–1 h^–1 ajmaline and in 1/8 animals by 4 mg kg^–1 h^–1 ajmaline. During sinus rhythm only 4 mg kg^–1 h^–1 ajmaline significantly increased QRS-duration and intraventricular activation times, but during rapid right ventricular pacing (cycle length = 330 ms) both doses of ajmaline increased QRS duration and intraventricular conduction times. 4 mg kg^–1 h^–1 ajmaline also increased the cycle length of induced sustained ventricular tachycardia. In 3 animals induction of sustained ventricular tachycardia during infusion of 4 mg kg^–1 h^–1 ajmaline was achieved by introduction of less extrastimuli than at baseline. Furthermore the coupling intervals of extrastimuli that induced sustained ventricular tachycardia were substantially prolonged by this dose. Inhomogeneity of conduction between left ventricular normal zone and left ventricular infarct zone was significantly increased by 4 mg kg^–1 h^–1 ajmaline during rapid right ventricular pacing, but not during sinus rhythm.We conclude that ajmaline has only limited efficacy with regard to the prevention of induction of sustained ventricular tachycardia after myocardial infarction. Drug-induced increases in tachycardia cycle lengths, as observed under the higher dose of ajmaline, were associated with a rate-dependent rise in cardiac electrical instability. Correspondence to H. Todt at the above address     

胺碘酮与艾司洛尔治疗老年患者急性心肌梗死合并室性心律失常的短期疗效与安全性比较

目的 比较老年急性心肌梗死（AMI）合并严重室性心律失常患者静脉应用胺碘酮或艾司洛尔48 h内疗效及不良反应,为临床安全用药提供依据. 方法 2009年1月至2013年6月在中国医科大学附属盛京医院心脏内科连续住院治疗的老年AMI合并严重室性心律失常患者纳入研究,分为胺碘酮组与艾司洛尔组.胺碘酮组患者在10 min内静脉注射胺碘酮150 mg＋ 5％葡萄糖注射液20 ml后经微量注射泵静脉输注胺碘酮1 mg/min共6h,减量至0.5 mg/min静脉输注24～48 h,之后口服胺碘酮0.2g,3次/d,共7d.艾司洛尔组患者在1 min内静脉注射艾司洛尔注射液0.5 mg/kg后经微量注射泵静脉输注艾司洛尔0.1 mg/（kg·min）共6h,减量至0.05 mg/（kg·min）静脉输注24 ～ 48 h,之后口服美托洛尔25 mg,2次/d,共7d.胺碘酮组和艾司洛尔组静脉应用胺碘酮或艾司洛尔6h后仍有室速发作者,分别加用上述艾司洛尔或胺碘酮治疗方案.比较2组患者治疗48 h内有效率和不良反应发生率. 结果 胺碘酮组和艾司洛尔组48 h内有效率分别为92.1％（35/38）和75.0％（27/36）,组间差异有统计学意义（P=0.046）;不良反应发生率分别为39.5％（15/38）和19.4％（7/36）,组间差异无统计学意义（P =0.060）.胺碘酮组2例伴有心力衰竭患者静脉用药24 h后出现急性肝损伤,停药并对症治疗2周后肝功能恢复正常. 结论 静脉应用胺碘酮治疗老年患者AMI合并严重室性心律失常有效率优于艾司洛尔.胺碘酮与艾司洛尔均较安全.高龄AMI且伴心力衰竭者静脉应用胺碘酮时需密切监测肝功能,出现肝损伤需立即停药并给予对症治疗.