Atrial fibrillation post-cardiac surgery: changing perspectives

ABSTRACT

Perioperative atrial fibrillation (AF) is one of the most frequent complications of cardiac surgery. Its development is associated with an increased morbidity and mortality, for example from perioperative stroke, as well as ventricular arrhythmias, postoperative myocardial infarction, congestive cardiac failure, renal failure, increased use of inotropic medications and the need for intra-aortic balloon pump. Furthermore, AF after cardiac surgery results in prolonged hospitalization after the procedure, as well as an excess utilization of hospital resources and increased hospital costs. Given the importance of AF for patient outcome, a wide variety of prophylactic pharmacologic strategies have been evaluated.

The risk of post-operative AF should be reduced by the administration of amiodarone, a beta- blocker, sotalol or rate-limiting calcium antagonists. In addition, in patients undergoing cardiac surgery on pre-existing beta-blocker therapy, this treatment should be continued unless contraindications develop (such as post-operative bradycardia or hypotension). Unless contraindicated, a rhythm control strategy is recommended as the initial option for the treatment of post-operative AF following cardiothoracic surgery. More recently, some data regarding magnesium, statins and n-3 olyunsaturated fatty acids in reducing post-op AF are available. Clearly, perspectives are changing in our management of this common arrhythmia.     

索他洛尔对急性心肌梗死血小板活化及纤溶活性和内皮血管活性物质的影响

目的 :探讨索他洛尔对急性心肌梗死 (AMI)血小板活化、纤溶活性和内皮血管活性物质的影响。方法 :新西兰大白兔 4 0只 ,随机分为 4组 ,每组 10只 ,Ⅰ组 :假手术组 ,Ⅱ组 :AMI组 ,Ⅲ组 :利多卡因组 ,Ⅳ组 :索他洛尔组 ;Ⅱ、Ⅲ、Ⅳ组分别结扎冠状动脉左室支中点 ,4h后取血分别测定血栓素B2 (TxB2 )、6 酮 前列腺素F1α(6 keto PGF1α)、内皮素 (ET)、一氧化氮 (NO)浓度和组织型纤溶酶原激活剂 (t PA)、纤溶酶原激活剂抑制物 (PAI)活性 ;摘取心脏 ,测定心肌梗死范围。结果 :Ⅱ、Ⅲ、Ⅳ组与Ⅰ组比较 ,血浆TxB2 、ET、NO浓度和PAI活性显著升高(P <0 .0 1) ,6 keto PGF1α浓度、t PA活性显著下降 (P <0 .0 1) ,Ⅲ组与Ⅱ组比较 ,差异无显著性意义 ,Ⅳ组与Ⅱ组比较 ,血浆TxB2 、ET、NO浓度和PAI活性明显降低 (P <0 .0 1) ,6 keto PGF1α浓度、t PA活性显著升高 (P <0 .0 1) ,梗死范围减小。结论 :索他洛尔抑制AMI早期血小板活化 ,改善纤溶活性 ,减少ET和NO的释放 ,缩小心肌梗死范围     

Investigating the effect of sotalol on the repolarization intervals in healthy young individuals

Background

The dissociation between a drug-induced increase of the QT interval prolongation and an increased risk for ventricular arrhythmias has been suggested by academic investigators and regulatory agencies. Yet, there are no alternative or complimentary electrocardiographic (ECG) techniques available for assessing the cardiotoxicity of novel compounds. In this study, we investigated a set of novel ECG parameters quantifying the morphology of the T-loop. In a group of healthy individuals exposed to sotalol, we compared their drug-induced changes to the drug-induced prolongations of the QTc, QTc apex and T-peak to T-end intervals.

Methods

We implemented a set of parameters describing the morphology of the T loop in its preferential plane. These parameters measure the time interval needed for the heart vector amplitude to change from its maximum value to a time when its amplitude has been reduced by 30%, 50%, and 70%. These measurements are called early repolarization duration (ERD) when they are located before the T-wave apex and late repolarization duration (LRD) when measured after the apex. They depend on both the speed of the repolarization process and the morphology of the T loop. Thirty-nine healthy individuals were exposed to sotalol in a crossover-design study. Sixteen ECGs were recorded per day during 3 days. The first day (day 0) was baseline; a single dose of sotalol (160 mg) was given during day 1, and a double dose was given during day 2 (320 mg). The plasma concentration of the drug was measured just before the ECG recordings.

Results

The values of all investigated parameters revealed a dose-dependent effect of sotalol (in average between parameters, ρ = 0.9, P < .001). Our investigations described profound and statistically significant changes in the morphology of the vectorial T loop for day 1 (peak effect of sotalol: ΔERD_50% = 23 ± 6 msec, P < .05; ΔLRD_50% = 8 ± 3 msec, P = .05) and day 2 (peak effect of sotalol: ΔERD_50% = 51 ± 14 msec, P < .05; ΔLRD_50% = 20 ± 12 msec, P = .05). When investigating the timing of peak drug concentration and peak effect of the drug on the various repolarization parameters, we found asynchrony between ERDs/LRDs (≥3.5 hours after dosing) and QTc/QTc apex profiles (<3.5 hours after dosing), suggesting that the time of maximum prolongation on the repolarization process was not synchronized with the time of maximum drug-induced heterogeneity of repolarization.

Conclusion

This study describes the sotalol-induced changes of the T-loop morphology in healthy individuals based on novel vectocardiographic parameters. These observations might help in improving the next generation of ECG markers for the evaluation of drug cardiotoxicity.     

胺碘酮和索他洛尔在心律失常治疗中的疗效及安全性比较

目的 比较临床常用的Ⅲ类抗心律失常药物胺碘酮和索他洛尔在心律失常治疗中的疗效及安全性,为临床用药提供依据.方法 选取我院2011年1月至2012年1月诊治的92例心律失常患者为研究对象,采用随机数字表法将其分为2个研究组,每组46例.两组分别使用口服胺碘酮与索他洛尔进行治疗.对所有研究对象进行心电图监测,并分别于治疗3个月、6个月、9个月、12个月、15个月及18个月对两组研究对象的转复率、转复时间及不良发应发生率进行比较及统计学分析.结果 胺碘酮组的转复率略高于索他洛尔组,但差异无统计学意义（P＞0.05）;胺碘酮组的转复时间长于索他洛尔组,且差异具有统计学意义（P＜0.05）;胺碘酮组的不良反应发生率为19.6％,低于索他洛尔组的28.3％,差异有统计学意义（P＜0.05）.结论 相对于索他洛尔,胺碘酮在心律失常的治疗中具有疗效显著、安全性更高等优势,且适用范围广泛,具有重要的临床价值,适于推广使用.     

胺碘酮与索他洛尔对QT离散度的影响及QT离散度改变对治疗室性心律失常的疗效预测价值

目的通过观察室性早搏(室早)患者治疗前后同步12导联心电图中QT离散度(QTd)及24小时动态心电图变化,分析胺碘酮和索他洛尔作用机制以及QTd应用的临床意义。方法室早患者60例包括Ⅰ组(胺碘酮静脉+口服),Ⅱ组(胺碘酮单纯口服)和Ⅲ组(索他洛尔口服),每组20例。所有患者均在用药前、用药后5天分别检测QT离散度(包括正常波QTd、室早波QTd及室早波随后正常波QTd),以及用药前、用药后两周分别做24小时动态心电图。结果所有患者用药前和用药后正常波QTd有明显的统计学差别(P<0.001),但用药前和用药后5天室早波QTd及室早随后正常波QTd无明显的统计学差别(P>0.05)。Ⅰ组患者总有效13例(65%),Ⅱ组患者总有效13例(65%),Ⅲ组患者总有效11例(55%)。Ⅰ组与Ⅱ组疗效较Ⅲ组为高,但经统计学检验无明显差别(P>0.05)。将所有患者按治疗后有效和无效分为两部分,有效部分和无效部分用药前和用药后5天QTd测定值均有明显的统计学差别(P<0.001),但两部分用药前后QTd差值无明显统计学差别(P>0.05)。结论胺碘酮和索他洛尔治疗效果相似,两者均可降低室早患者的QTd。QTd对于抗心律失常药物疗效无预测价值。     

盐酸索他洛尔注射液内毒素检查方法探讨

目的:探讨盐酸索他洛尔注射液细菌内毒素检查法的可行性.方法:根据<中国药典>2005版细菌内毒素检查法,运用干扰初筛法对供试品进行干扰试验和内毒素限量检查.结果:盐酸索他洛尔注射液对本检查法无干扰作用,用灵敏度为0.25EU/ml鲎试剂检测细菌内毒素的方法可行、有效.结论:可以用细菌内毒素检查法代替家兔法来控制盐酸索他洛尔注射液的质量.     

索他洛尔与胺碘酮转复心房颤动的疗效对比

目的 观察对比两种目前临床治疗心房颤动的常用药品的剂量疗效,提供临床治疗的经验.方法 选择门诊心房颤动患者344例,随机按每病种分成两组,分别服用索他洛尔与胺碘酮,调整用药剂量治疗并观察12个月.结果 索他洛尔组与胺碘酮组各为172人,索他洛尔组心房颤动转为窦性心律45人,转复率26.2%,复发5例,转复后窦性心律维持率88.9%;胺碘酮组心房颤动转为窦性心律41人,转复率23.8%,复发2例,转复后窦性心律维持率95.1%.结论 索他洛尔组治疗心房颤动的转复率略高于胺碘酮组,转复后窦性心律维持率胺碘酮组高于索他洛尔组.     

2种用药方案治疗心房颤动的成本-效果分析

目的:比较胺碘酮与索他洛尔治疗心房颤动(AF)的成本与效果。方法:102例患者均分成A、B组,分别给予胺碘酮、索他洛尔治疗,并进行成本-效果分析。结果:2组成本分别为2714.18、2176.56元,有效率分别为78.43%、70.59%(P<0.01),不良反应发生率分别为13.73%、19.61%(P<0.01)。结论:胺碘酮转复房颤有效率与索他洛尔相当,但维持窦律疗效优于索他洛尔,对心脏毒副作用小于索他洛尔。     

索他洛尔联合普罗帕酮治疗阵发性房颤的效果观察

目的观察索他洛尔联合普罗帕酮在房颤转复后维持窦律的临床疗效和安全性。方法阵发性心房颤动患者29例,分为两组。治疗组(Ⅰ组)13例,用索他洛尔转复房颤,恢复窦律后索他洛尔80mg/ d联合普罗帕酮300mg/d口服维持。对照组(Ⅱ组)16例,可达龙(即胺碘酮)转复房颤,恢复窦律后可达龙0．2g/d或0．2g/d、每周5d,口服维持。每周观察心率、Q—T间期、房颤发作次数、持续时间、药物不良反应,随访3个月。结果Ⅰ组、Ⅱ组治疗显效率分别为69．23%、80%；有效率分别为30．77%、20%；两组治疗效果无显著性差异(均P＞0．05)。治疗后两组窦性心率较治疗前减慢,差异显著(均P＜0．01),但组间无明显差异(P＞0．05)。治疗后两组Q—T间期较治疗前无显著性差异(均P＞0．05),组间亦无显著性差异(P＞0．05)。无其它不良反应。结论小剂量索他洛尔联合普罗帕酮在房颤转复后维持窦律方面,治疗效果好、安全性高、依从性强。     

The treatment of cardiac arrhythmias with sotalol

Summary Sotalol, at a fixed dose of 20 mg was given intravenously to 34 patients with cardiac arrhythmias of varying aetiology. It was effective in the treatment of supraventricular tachycardias, acute onset atrial and ventricular ectopics and acute onset atrial fibrillation. In chronic arrhythmias sinus rhythm was not restored, but in 77% there was slowing of the cardiac rate. Side effects were seen in only one patient who developed moderate bronchospasm.