A formula for the stratified selection of patients with paroxysmal atrial fibrillation in the emergency setting: a retrospective pilot study

Background: Amiodarone is a commonly used medication in the treatment of atrial fibrillation (AF) of recent onset. Study Objectives: The aim of the study was to identify a possible formula for selecting Emergency Department (ED) patients with paroxysmal AF who will spontaneously restore sinus rhythm (SR), successfully restore SR with the use of loading intravenous (i.v.) amiodarone, or require 24-h maintenance amiodarone infusion. Methods: This retrospective pilot study included 141 patients with recent-onset AF. Patients who did not restore SR spontaneously received i.v. amiodarone (5 mg/kg) within a period of 30 min. In case of no response, an additional dosage of 1000 mg of i.v. amiodarone was administered over a period of 24 h. Binary logistic regression models were used to determine the predictors of spontaneous conversion and the response to amiodarone administration. Results: The formula ([heart rate/systolic blood pressure] + 0.1 × number of past AF incidences) was chosen as the one with the highest combined sensitivity and specificity. This index identified the patients who spontaneously restored SR (cutoff point 1.31 with 78.6% sensitivity and 77.9% specificity), whereas for patients who responded to the loading i.v. amiodarone dose, the use of the index (cutoff point 1.24) exhibited 84.1% sensitivity and 75.3% specificity. Conclusions: This formula may be a useful and reliable bedside diagnostic tool to identify AF patients most likely to spontaneously convert, or respond to loading amiodarone administration in the emergency setting. The use of this index also can assist in patient risk stratification.     

Clinical study of amiodarone-associated torsade de pointes in Chinese people

OBJECTS: Amiodarone-associated torsade de pointes (Tdp) has been reported increasingly in China in recent years. In this study, we made clinical analysis of amiodarone-associated Tdp in Chinese people. METHODS: Two major Chinese medical databases were searched to identify articles published during the last 26 years that presented data on amiodarone-associated proarrhythmic events. The articles were divided into two categories: case reports and observational studies. RESULTS: Fifty-two Chinese-language case reports with 98 patients and 2 patients registered in our hospital, total 100 patients about amiodarone-associated Tdp, were enrolled in the study. Amiodarone-associated Tdp occurred more frequently in females (68.0%, 68/100). The major primary disease of females was rheumatic heart disease (40.7%, 24/59), while that of males was coronary heart disease (45.8%, 11/24). In most patients, Tdp occurred repeatedly and terminated in 24-48 hours. Some Tdp worsen to ventricular fibrillation and caused 19 patients' death (mortality rate 21.8%, 19/87). Known predisposing factors to the development of Tdp, such as heart failure, hypokalemia, drugs combination, and bradyarrhythmia, existed in many cases. Tdp also occurred in six patients (4 females, 2 males) without any known predisposing factors except QTc interval prolongation. Fourteen observational studies each reported data from at least 100 patients who were treated with amiodarone for at least 1 month. Of 2,354 patients included in these studies, 455 patients exposed to amiodarone were reported to have proarrhythmic events (an overall incidence of 19.3%), while only 4 patients were reported to have Tdp or ventricular fibrillation (an incidence of 0.17%). CONCLUSIONS: In conclusion, approximately one-fifth of the patients have amiodarone-induced proarrhythmic events, while the incidence of Tdp or ventricular fibrillation is remarkably low. Amiodarone-associated Tdp occurred more frequently in Chinese females. Known predisposing factors for occurrence of Tdp prevailed in Chinese patients. QTc interval prolongation may be an independent risk factor of amiodarone-associated Tdp.     

Antiadrenergic therapy in the control of atrial fibrillation

Atrial fibrillation (AF) in heart failure develops commonly in older individuals and its prevalence increases as heart failure severity progresses. Because of deteriorating hemodynamics, patients with heart failure are at increased risk for developing AF and, conversely, AF in heart failure patients is associated with adverse hemodynamic changes. AF is believed to increase the mortality risk in heart failure, which may be minimized by treatment that includes the control of ventricular rate, prevention of thrombotic events, and conversion to normal sinus rhythm. Clinical guidelines recommend amiodarone or dofetilide in heart failure patients, but these drugs have certain drawbacks, such as an increased risk for bradyarrhythmias with amiodarone and proarrhythmic reaction with dofetilide. Some but not all clinical trials have suggested that rate control should be the primary therapeutic goal in high-risk heart failure patients with AF and, if unsuccessful, followed by rhythm control. The former is effectively achieved with rate-lowering beta-blockers alone or in combination with digoxin. Recent studies evaluating the effects of combination carvedilol/digoxin therapy demonstrate synergistic effects between the two drugs. This combination therapy decreased heart failure symptoms, effectively reduced ventricular rate, and improved ventricular function to a greater extent compared with that produced by either drug alone. Although digoxin alone is an effective heart failure treatment, its use as a single rate-control therapy is often ineffective in heart failure patients with AF associated with rapid ventricular response. Carvedilol is effective, alone or in combination, with digoxin in such heart failure patients with AF, and has been shown to reduce mortality risk in patients with chronic heart failure during prolonged therapy.     

Hepatotoxicity during rapid intravenous loading with amiodarone: Description of three cases and review of the literature

OBJECTIVE: Atrial fibrillation is the most common arrhythmia after cardiac surgery. Amiodarone can effectively prevent and control postoperative atrial and ventricular fibrillation. Acute hepatic damage after intravenous amiodarone, which can be fatal, is not well recognized. We describe three cases of acute hepatocellular injury after intravenous amiodarone administration in critically ill patients. Another 25 published cases and six cases reported to the Swiss Pharmacovigilance Center (Swissmedic) are discussed. DESIGN: This study consisted of a series of three case reports and review of the literature. SETTING:: This study was conducted at an operative critical care unit at the University Hospital Basel, Switzerland. PATIENTS: Three hemodynamically compromised patients after open heart surgery developed significant increases of transaminases (up to more than 100-fold of the upper limit of normal) shortly after the introduction of intravenous amiodarone. INTERVENTIONS AND MEASUREMENT: Cessation of intravenous amiodarone and of other potentially hepatotoxic drugs. RESULTS: Liver parameters significantly improved or returned to normal in all three patients, even after start of oral amiodarone in two patients. CONCLUSIONS: Amiodarone is a highly effective antiarrhythmic agent for the treatment and prevention of atrial and ventricular arrhythmias. Acute liver damage after intravenous amiodarone, possibly induced by the solubilizer polysorbate 80, is rare but potentially harmful. Amiodarone loading should therefore be adapted to the necessity of an immediate effect of the drug, and liver function should be monitored closely in critically ill patients. Oral maintenance therapy with amiodarone is possible, even in patients who developed liver disease during intravenous loading.     

Rhythm control agents and adverse events in patients with atrial fibrillation

Background: Atrial fibrillation (AF) is the commonest rhythm disorder and has major impact on patients. Controversy remains about the best treatment strategy between rate and rhythm control (in addition to adequate thromboprophylaxis). Rhythm control agents are associated with clinically important adverse events. Aim: The aim of this study was to assess the risk of adverse events in patients with AF receiving rhythm control agents. Design of study: This is a retrospective case control note review and outcome linkage analysis. Setting: Setting of this study included patients with a diagnosis of AF receiving amiodarone, flecainide or sotalol in practices registered with the General Practice Research Database (GPRD) in the UK. Method: This is a retrospective case control note review and outcome linkage analysis on the GPRD routine clinical dataset to evaluate the adverse events and predictors of treatment discontinuation in patients using licenced rhythm modifying medication. Results: Adverse events are more common in patients currently or previously taking amiodarone, flecainide or sotalol than age‐ and gender‐matched controls. All three antiarrhythmics were associated with increased all‐cause mortality. Congestive heart failure was more common in all amiodarone and sotalol users as well as past users of flecainide. Thyroid disease was more common in patients treated with amiodarone and sotalol but only amiodarone had an increased risk of pulmonary toxicity. The number of patients with liver failure was too small in all cases for statistical analysis. Conclusion: The rhythm control agents amiodarone, flecainide and sotalol have significant adverse effects which can lead to discontinuation of their use. This should be considered when deciding the most appropriate treatment option for patients with AF.     

Stability of Electrophysiological Parameters after Acute Amiodarone Loading: Implications for Patient Management

The appropriate timing of electrophysiological study in patients treated with amiodarone is uncertain. Twenty patients with coronary artery disease in whom sustained ventricular tachycardia was still inducible after 9 ± 1 days of amiodarone loading (1,200-1,400 mg/day) underwent repeat electrophysiological testing after an additional month of maintenance therapy (400 mg/day). Compared with baseline, both short- and long-term amiodarone therapy caused significant changes in QT_c, right ventricular elective refractory period, and ventricular tachycardia cycle length. However, there was no significant change in electrophysiological parameters between the end of the acute amiodarone loading period and 1 month of additional therapy. Sustained ventricular tachycardia remained inducible in 19 of 20 patients after 1 month of maintenance therapy. Amiodarone and desethylamiodarone plasma concentrations remained stable after amiodarone loading, but did not correlate with the magnitude of electrophysiological changes from baseline. These data suggest that electrophysiological testing after 9 days of high dose amiodarone therapy may accurately reflect long-term electrophysiological effects.     

Hepatic dysfunction and neurotoxicity in a patient receiving long-term low-dose amiodarone therapy

Background: Amiodarone is commonly used in the treatment of refractory paroxysmal atrial fibrillation. Much of the literature focuses on the toxic effects of this medication in the setting of rapid loading or long-term therapy with high maintenance doses. However, patients have been known to develop multi-organ toxicities with long-term low-dose therapy. Case Report: We present a 90-year-old man with paroxysmal atrial fibrillation undergoing low-dose amiodarone therapy for a period of 18 months without medical follow-up who developed signs and symptoms consistent with neurotoxicity and hepatotoxicity in association with hyperammonemia. Upon discontinuation of the medication and treatment of the hyperammonemia, the patient had a rapid decline in symptoms and a return to his baseline status. Conclusion: Identifying toxicity early and correcting it rapidly may prevent life-threatening sequelae associated with amiodarone toxicity.     

胺碘酮转复心房颤动的疗效分析

目的观察重叠应用静脉及口服胺碘酮治疗并发于器质性心脏病的心房颤动的临床疗效及安全性。方法39例心房颤动患者先给予静脉负荷量胺碘酮(150~300 mg)后,继之以0.6 mg/min静脉点滴维持48 h;同时口服胺碘酮治疗,2周内给胺碘酮负荷量7 g,然后维持量0.2 g/d。观察临床疗效及不良反应。结果32例(82.1%)患者成功转复为窦性心律,于2 h、2~24 h、24~48 h、2~7 d转复率分别为12.8%、28.2%、23.1%、18.0%。未转复组患者左房径大于转复组(P<0.05),而射血分数明显低于转复组(P<0.05),这可能是7例患者未转复的原因。2例患者用药后出现窦性心动过缓,1例出现恶心、腹胀,经减药后恢复。结论静脉及口服胺碘酮治疗并发于器质性心脏病的心房颤动是有效且较安全的方法。     

胺碘酮联合稳心颗粒冲剂治疗心力衰竭并室性心律失常的疗效

目的探讨胺碘酮联合稳心颗粒冲剂治疗心力衰竭并室性心律失常的临床疗效及安全性。方法将80例心力衰竭并室性心律失常患者按入院的先后顺序分为2组：观察组和对照组,每组40例。2组患者均采用常规的抗心力衰竭及胺碘酮片治疗。在此基础上,观察组加用稳心颗粒冲剂治疗。观察2组患者控制室性心律失常疗效、心功能疗效的情况。结果观察组患者控制室性心律失常总有效率、心功能改善总有效率均明显高于对照组（97,50％比80．00％、95．00％比75．00％,均P〈O．05）。结论采用胺碘酮联合稳心颗粒冲剂治疗心力衰竭并室性心律失常安全、有效,无明显的不良反应,无诱发心肌缺血及心律失常,值得临床应用。     

Different Effects of Amiodarone and Quinidine on the Homogeneity of Myocardial Refractoriness in Patients With Intraventricular Conduction Delay

BACKGROUND: Increases in QT and JT dispersion have been suggested as indicative of a proarrhythmic potential as a result of heterogeneity in myocardial refractoriness, the reduction of which by antiarrhythmic agents might be associated with a beneficial effect on the development of serious ventricular arrhythmias. METHODS: To test the hypothesis that amiodarone reduces the heter-ogeneity of ventricular refractoriness to a significantly greater extent than quinidine in patients with intraventricular conduction defects under treatment for ventricular arrhythmias, the corrected and uncorrected QT and JT intervals and dispersions from 12-lead surface electrocardiograms were determined in 120 patients with intraventricular conduction defects with cardiac arrhythmias before and during treatment with amiodarone (n = 60) and quinidine (n = 60). RESULTS: Amiodarone increased QT from 403 +/- 50 ms to 459 +/- 47 ms (P <.001), with a similar increase in the corrected QT interval (QTc) (P <.001). Amiodarone reduced QT dispersion by 40% (P <.001), whereas quinidine increased by 18% (P <.001). The net effects of both drugs were similar for OTc. Amiodarone, but not quinidine, reduced heart rate significantly; amiodarone had no effect on the QRS; but quinidine increased if (P <.001). Quinidine as well as amiodarone increased the JT and JTc intervals significantly, but the effect of quinidine was qualitatively less striking. Amiodarone decreased the JT dispersion by 33% (P <.001) and JTc dispersion by 37% (P <.001). On the other hand, quinidine increased the corresponding values for JT and JTc by 18% (P <.001) and 21% (P <.001), respectively. The overall data on QT and JT dispersion indicate an improvement in the homogeneity of myocardial refractoriness with amiodarone treatment and the converse with quinidine treatment; this observation is consistent with a lower proarrhythmic propensity and mortality with amiodarone than with quinidine. Quinidine increased the QRS interval more than amiodarone, and the data indicate that in patients with intraventricular conduction defects, the monitoring of the JT interval might more accurately reflect changes in myocardial repolarization. CONCLUSIONS: Amiodarone and quinidine both increased the corrected and uncorrected QT and JT intervals; amiodarone decreased and quinidine increased the dispersion of these intervals, and these results suggested an improvement in the homogeneity of myocardial refractoriness as a result of amiodarone treatment and the converse as a result of quinidine treatment. Quinidine increased the QTS interval more than amiodarone, and the data indicate that in patients with intraventricular conduction defects, the monitoring of the JT interval might more accurately reflect changes in myocardial repolarization.     

围术期应用胺碘酮预防心脏不停跳冠状动脉搭桥术后房颤的研究

目的探讨围手术期应用胺碘酮在预防非体外循环下心脏不停跳冠状动脉搭桥术后房颤中的作用。方法采用随机对照的研究方法,将2009年1月至2011年1月在我科进行非体外循环下心脏不停跳冠状动脉搭桥术的患者随机分为试验组和对照组,每组各100例。A组为试验组,术前口服胺碘酮,600mg/d(200mgtid),连续7d,之后改为200mg/d至术前,术后当天开始静脉滴注胺碘酮,负荷量为5mg/kg,之后给予维持量0.5mg.kg-1.h-1,能进食后改为200mg/d口服。B组为对照组,不给予胺碘酮治疗而仅用常规药物。观察两组患者术后房颤发生率及心率变化,同时检测试验组患者术前及术后第2天的胺碘酮血药浓度。结果两组患者的术前一般特征及手术情况相近。试验组100例患者中术后有10例(10.0%)发生房颤,对照组100例患者中有36例(36.0%)发生房颤(P=0.015)。试验组房颤时最大心室率为(126.0±20.8)次/min,房颤持续时间为1.0d,对照组房颤时最大心室率为(150.0±25.6)次/min,房颤持续时间为(3.0±1.5)d(P<0.05)。试验组术后心率慢于对照组,两组Q-T间期、术后并发症的发生及死亡率无统计学差异。试验组的住院时间为(10.6±2.8)d,对照组住院时间为(15.4±3.2)d(P<0.05)。胺碘酮血药浓度平均值术前为(797±136)ng/ml,术后第2天为(763±94)ng/ml(P>0.05)。结论胺碘酮在预防非体外循环下心脏不停跳冠状动脉搭桥术后房颤中的作用显著,能安全有效地降低术后房颤的发生率,缩短房颤持续时间,且无明显不良反应。     

静脉及口服胺碘酮同时应用治疗充血性心力衰竭心房颤动伴快速心室率的临床分析

目的：探讨胺碘酮治疗充血性心力衰竭（CHF）心房颤动伴快速心室率的临床疗效。方法：将106例各种原因所致的房颤伴快速心室率的CHF患者按入院顺序随机分为治疗组及对照组。两组抗CHF基础治疗相同,治疗组加用静脉负荷量胺碘酮150 mg后,再以1000μg/min静脉点滴维持6小时,500μg/min静滴18小时。同时口服胺碘酮0.2,3次/d,1周;再0.2,2次/d,1周以后以0.2,1次/d至观察终点,随诊为12个月。结果：治疗组53例使用胺碘酮治疗可显著增加抗心律失常有效性,改善左室射血分数,减少心力衰竭再住院率,42例患者转复为室性心律。结论：静脉及口服胺碘酮同时应用治疗充血性心力衰竭房颤是有效和安全的。     

胺碘酮治疗慢性心力衰竭伴快速心房纤颤86例的疗效评价

【目的】评价胺碘酮治疗充血性心力衰竭（CHF）伴快速心房颤动（Af）患者的临床疗效及安全性。【方法】本院86例CHF伴快速Af（心功能级Ⅱ～Ⅳ级）患者,随机分为胺碘酮组（A组）、毛花洋地黄甙组（B组）,每组43例。在常规治疗的基础上,A组首次剂量给予150mg胺碘酮缓慢静注,随后0．5-1．0rag／rain微量泵维持;B组首次剂量给予毛花洋地黄甙0．4mg或0．2mg缓慢静注,1h后无效者追加0．2mg。观察用药后12h临床疗效、心电图改善、30、60、90min转复成功率及不良反应。【结果】两组患者用药后临床疗效比较差异无显著性（P〉0．05）;A组与B组心电图表现：转复为窦性心律及基础心室率下降分别为17例（占39．53％）、24例（占55．81％）,8例（占18．60％）、19例（占44．19％）,两者比较差异有显著性（P〈0．05）;A组窦性心律转复成功率显著高于B组（P〈0．05）;两组不良反应相比无显著性差异（P〉0．05）。【结论】静脉应用胺碘酮治疗CHF伴快速Af比毛花洋地黄甙更加快速、安全、有效。     

Efficacy of magnesium-amiodarone step-up scheme in critically ill patients with new-onset atrial fibrillation: a prospective observational study

Amiodarone is considered a first-choice antiarrhythmic drug in critically ill patients with new-onset atrial fibrillation (AF). However, evidence supporting the use of this potentially toxic drug in critically ill patients is scarce. Magnesium sulphate (MgSO4) has shown to be effective for both rate and rhythm control, to act synergistically with antiarrhythmic drugs, and to prevent proarrhythmia. Treatment with MgSO4 may reduce the need for antiarrhythmic drugs such as amiodarone in critically ill patients with new-onset atrial fibrillation. The efficacy of a new institutional protocol was evaluated. Patients were treated with a new institutional protocol for new-onset atrial fibrillation in critically ill patients. An MgSO4 bolus (0.037 g/kg body weight in 15 minutes) was followed by continuous infusion (0.025 g/kg body weight/h). Intravenous amiodarone (loading dose 300 mg, followed by continuous infusion of 1200 mg/24 h) was given to those not responding to MgSO4 within 1 hour. Clinical response was defined as conversion to sinus rhythm or decrease in heart rate <110 beats/min. Sixteen of the 29 patients responded to MgSO4 monotherapy, whereas the addition of amiodarone was needed in 13 patients. Median (range) time until conversion to sinus rhythm after MgSO4 was 2 (1-45) hours. Median (range) conversion time in patients requiring amiodarone was 4 (2-78) hours, and median (range) conversion time in all patients was 3 (1-78) hours. The 24-hour conversion rate was 90%. Relapse atrial fibrillation was seen in 7 patients. The magnesium-amiodarone step-up scheme reduces the need for amiodarone, effectively converts new-onset atrial fibrillation into a sinus rhythm within 24 hours, and seems to be safe in critically ill patients.     

胺碘酮治疗老年器质性心脏病所致室性心律失常的疗效

【目的】评价胺碘酮对老年器质性心脏病室性心律失常患者的疗效。【方法】入选经心电图及Holter确诊的56例室性心律失常患者,接受静脉加口服或单纯口服胺碘酮治疗,观察治疗前后心律失常改善情况及药物安全性。【结果】10例恶性室性心律失常电复律后使用静脉胺碘酮治疗7例有效,口服胺碘酮治疗6个月有效率达92．7％,29例患者治疗后发生轻度QTC延长,22例发生窦缓,1例发生甲状腺功能减低,6例静脉治疗者出现心功能恶化,所有患者用药后均未发现肝功能、外周血象、皮肤或周围神经异常。【结论】胺碘酮治疗老年器质性心脏病所致室性心律失常安全、有效。     

猝死患者在心肺复苏过程中出现室性心率失常时胺碘酮的应用

目的：研究猝死患者在心肺复苏过程中出现室性心率失常时胺碘酮的应用。方法：选心肺复苏过程中出现的室性心律失常患者共107例,随机分为治疗组57例采用胺碘酮治疗,对照组50例采用利多卡因治疗,持续心电监护观察其疗效。结果：治疗组、对照组有效率分别为93.1%、80.0%,有显著性差异。结论：胺碘酮组的疗效明显高于利多卡因组,在治疗心肺复苏过程中室性心律失常应首选胺碘酮。     

Effect of coexisting cardiovascular disease on the long-term efficacy and safety of the implantable atrial defibrillator

The long-term efficacy and safety of implantable atrial defibrillator (IAD) therapy in patients with AF and cardiovascular disease is unclear. The aim of this study was to evaluate the efficacy and safety of IAD therapy in patients with and without coexisting cardiovascular disease. In 115 patients implanted with an IAD, 85 patients had cardiovascular disease: 41 (48%) patients had 1 cardiovascular abnormality, 29 (35%) patients had 2, 13 (15%) patients had 3, and 2 (2%) patients had 4 different cardiovascular abnormalities. The device was programmed into a rhythm monitoring mode for the first 3-month postimplant period. All defibrillation therapy was performed under physician supervision to monitor safety and efficacy. After this initial monitoring period, patients were allowed to activate their device away from the hospital or clinic. A total of 357 spontaneous AF episodes occurred in 83 (72%) patients during observed operation and the mean shock efficacy was 93.5+/-20.3% (lower 95% confidence interval [CI] 89.8%). As of the lastfollow-up, 58 (55%) patients had transition to receive nonphysician observed therapy. Forty-two (72%) patients had experienced 332 episodes of AF for which theyhad received device therapy away from the hospital/clinic (mean shock efficacy 90.5+/-39.7%). The presence of hypertension, valvular heart disease, and ischemic heart disease did not affect the shock efficacy of the IAD during physician observed and nonobserved therapy (P > 0.05). However, the presence of congestive heart failure was associated with a lower clinical efficacy during observed and nonobserved therapy (P < 0.05). Overall, 5,262 shocks have been delivered with the IAD without any episode of proarrhythmia. The observed proarrhythmic risk was 0%, with an estimated maximum proarrhythmic risk of 0.06% per shock (95% upper CI). A stand-alone IAD appears to be safe in the presence of cardiovascular disease. The lower clinical efficacy for AF associated with congestive heart failure might be related to a higher rate of early reinitiation of AF after defibrillation.     

First time and repeat cardioversion of atrial tachyarrhythmias – a comparison of outcomes

Introduction: Repeat cardioversion may be necessary in over 50% of patients with persistent atrial fibrillation (AF), but identifying responders remains challenging. This study evaluates the long‐term success of direct current cardioversion (DCCV) and the clinical and echocardiographical parameters that influence them, in over 1000 sedation‐cardioversion procedures undertaken at Eastbourne General Hospital between 1996 and 2006. Methods: A total of 770 patients of mean age (SD) 70.1(10.1) underwent 1013 DCCVs (first n = 665, repeat n = 348) for atrial tachyarrhythmias from 1996 to 2006. Time to persistent arrhythmia recurrence was compared between first and multiple DCCV, and the effect of age, gender, presence of heart disease, left atrial size, fractional shortening, arrhythmia duration, anti‐arrhythmic drug therapy (AAD) and other concomitant cardiac medication was evaluated using the Kaplan–Meier method and Cox’s Proportional‐hazards model. Results: In all, 33% of first and 29% of repeat DCCVs were in sinus rhythm (SR) at 12 months (m). There was no difference in median time to arrhythmia recurrence (SE) between first and multiple procedures: 1.5 ± 0.1 m (1.3–1.7) and 1.5 ± 0.0 m (1.4–1.6) respectively, p = 0.45. AAD use was significantly higher, arrhythmia duration shorter and more diabetic patients underwent repeat procedures. Amiodarone, OR 0.56, p = 0.04, sotalol, OR 0.61, p = 0.02 and arrhythmia duration, < 6 m, OR 0.72, p = 0.03 were independent predictors of improved outcome in first procedures only. In patients undergoing first procedures on amiodarone or sotalol, median time to arrhythmia recurrence was longer and 12 m SR rates higher, 6.0 ± 2.4 m (42%) than those who had a repeat procedure on the same medication, 1.5 ± 0.1 m (33%), p = 0.06. Conclusions: The efficacy of first and subsequent DCCV procedures is similar, achieving a similar proportion of SR maintenance at 1 year. However, the benefits of AAD therapy are the greatest following first time procedures. Concomitant AAD therapy should be considered for all first time procedures for persistent AF.     

胺碘酮与慢心律联合治疗顽固性室性早搏的疗效观察

目的 :观察胺碘酮与慢心律联合治疗顽固性室性早搏的疗效和安全性。方法 :17例顽固性室性早搏病人给予胺碘酮口服负荷量后加维持量 ,同时联合口服慢心律。结果 :15例 (88% )得到有效控制 ,未见严重毒副作用。结论 :胺碘酮与慢心律联合治疗顽固性室性早搏有良好的临床疗效及安全性     

Efficacy and Safety of Combination Therapy with Amiodarone and Type I Agents for Treatment of Inducible Ventricular Tachycardia

In a prospective study the efficacy of amiodarone in combinalion with the three Class I drugs mexiletine, fiecainide, orencainide was evaluated consecutively in 12 patients with recurrent venlriculav tachycardias (VT) by programmed stimulation. None of the tested drug combinations suppressed induction of sustained VT. The combination of amiodarone with Class IC drugs fJecainide and encainide prolonged the cycle length of VT significantly, whereas the combination with mexiletine did not hove the same degree of slowing on the VT cycle length. Several proarrhythmic effects occurred during the combination therapy with encainide: (1) frequent, spontaneous recurrences of hemodynamically well tolerated VT in four patients; (2) enhanced inducihilily of VT in three patients; (3) impaired termination of VT in three patients. Though a marked increase in QRS and QTc intervals was observed by combined treatment with encainide, no significant correlation could be established between aggravation of arrhythmia and plasma levels of encainide, degree of QRS widening, JT or QTc prolongation. The only predictor for the occurrence of proarrhythmic events was found in left ventricular ejection fraction. These findings suggest that in patients refractory to amiodarone alone or a combination with mexiletine, the combined treatment of amiodarone with other Class IC drugs prolongs the VT cycle length but does not suppress induction of VT during programmed stimulation. Combination therapy of amiodarone with encainide was associated with a high incidence of proarrhythmic effects.