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.     

"Torsade de pointes" in patients with structural heart disease and atrial fibrillation treated with amiodarone, beta-blockers, and digitalis

Amiodarone is one of the most efficient and safe antiarrhythmic drugs in the treatment of atrial fibrillation (AF). Yet, though rare, proarrhythmic effects remain a clinical problem. We present three cases of amiodarone-associated "Torsade de pointes" tachycardia (Tdp) in patients treated concomitantly with heart rate controlling medication for AF. Amiodarone loading therapy was started for the treatment of tachyarrhythmic AF in all the three patients. All presented with a history of coronary heart disease, resulting in a severely reduced left ventricular ejection fraction in two patients. One received oral amiodarone loading, in the others, amiodarone was administered intravenously because of hemodynamically relevant AF episodes. Amiodarone therapy was combined with a heart rate controlling medication including a β-blocking agent and digitalis in all the cases. All the subjects suffered from clinically relevant Tdp in the early run after initiation of amiodarone loading (max. 48 hours). The mean QTc in all patients before induction of Tdp was prolonged. The present case reports imply that amiodarone in combination with β-blocker/digitalis therapy may be associated with an elevated proarrhythmic risk in selected patients with structural heart disease and AF.     

Amiodarone: An emergency medicine perspective

Amiodarone is a highly efficacious antiarrhythmic agent for many cardiac arrhythmias, ranging from atrial fibrillation to malignant ventricular rhythm disturbances. Significant interest has developed in recent years with the publication of randomized controlled trials supporting the efficacy of amiodarone over placebo and lignocaine for improving survival to hospital in patients with shock‐resistant ventricular fibrillation. Amiodarone has complex pharmacological and pharmacokinetic properties. It has significant long‐term adverse effects, but short‐term administration of intravenous amiodarone is generally well tolerated. This article will explore issues related to the clinical use of amiodarone from an emergency medicine perspective.     

Amiodarone: guidelines for use and monitoring

Amiodarone is a potent antiarrhythmic agent that is used to treat ventricular arrhythmias and atrial fibrillation. The drug prevents the recurrence of life-threatening ventricular arrhythmias and produces a modest reduction of sudden deaths in high-risk patients. Amiodarone is more effective than sotalol or propafenone in preventing recurrent atrial fibrillation in patients for whom a rhythm-control strategy is chosen. When long-term amiodarone therapy is used, potential drug toxicity and interactions must be considered. The dosage of amiodarone should be kept at the lowest effective level. In patients who also are taking digoxin and warfarin, physicians must pay close attention to digoxin levels and prothrombin time, keeping in mind that the effects of interaction with amiodarone do not peak until seven weeks after the initiation of concomitant therapy. Laboratory studies to assess liver and thyroid function should be performed at least every six months.     

Ibutilide for rapid conversion of atrial fibrillation or flutter in a mixed critically ill patient population

INTRODUCTION: Ibutilide is an intravenous class III antiarrhythmic agent that has been shown to be effective in converting acute onset atrial fibrillation/flutter in stable medical and cardio-surgical patients. Data on its use in critically ill patients are rare. The aim of this open, non-randomized, prospective trial was to assess the potential role of ibutilide for conversion of recent onset atrial fibrillation/flutter in a mixed critically ill ICU-population. METHODS: Twenty cardiac-surgical and 17 medical patients with acute tachycardic atrial fibrillation or flutter received up to two 10-min intravenous infusions of 1.0 mg ibutilide. RESULTS: The cumulative conversion efficacy of ibutilide was 56.8% (21 of 37 patients). The mean time to termination of the arrhythmia was 17.7 +/- 12.5 min (range 4 to 45 min) after the start of the first infusion. Conversion success was significantly higher in medical compared to cardiac-surgical patients (82.4 versus 35.0%, p=.0063). In a multivariate binary stepwise logistic regression analysis adjusted for age, heart rate and reduced left ventricular function, cardiac surgery remained significantly associated with a lower conversion probability (RR, .14; 95%CI, 0.02 to 0.76; p=.0190). Serious, ibutilide-induced ventricular arrhythmias developed in 3/37 patients (8.1%). Two of these 3 patients had a left ventricular ejection fraction < 20%. CONCLUSION: Ibutilide is an effective treatment for conversion of acute tachycardic atrial fibrillation/flutter in critically ill patients. Higher efficacy can be expected in medical than cardiac-surgical patients. Ventricular proarrhythmia, especially in patients with severely depressed left ventricular function represents the most important limitation of ibutilide treatment.     

Rapid acute amiodarone-induced hepatotoxicity in a burn patient

Acute burn and trauma patients have a higher frequency of cardiac arrhythmias than would be expected for noncardiac-hospitalized patients. Amiodarone is an effective, commonly used drug for cardiac arrhythmias in this patient population. We present a 54-year-old white man treated in the burn intensive care unit for 70% TBSA burns. The patient developed an acute increase in liver enzymes within days of starting intravenous amiodarone for the control of atrial fibrillation. A full radiologic hepatobiliary investigation did not reveal a source for hepatotoxicity. Discontinuation of amiodarone resulted in a rapid decrease in liver enzyme levels to baseline values. It is important to identify amiodarone as a potential cause of severe hepatotoxicity in burn patients, despite short duration of use and a low cumulative dose.     

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。     

Amiodarone versus diltiazem for rate control in critically ill patients with atrial tachyarrhythmias

OBJECTIVE: To compare the rate-lowering effect of diltiazem and two amiodarone regimens in critically ill patients with recent-onset atrial tachyarrhythmias. DESIGN: Prospective, randomized, controlled study. SETTING: Medical cardiologic intensive care unit in a university hospital. PATIENTS: Sixty critically ill patients (Acute Physiology and Chronic Health Evaluation [APACHE] III score 70 +/- 30, age 67 +/- 10 yrs). INTERVENTIONS: Patients with atrial fibrillation (n = 57), atrial flutter (n = 2), or atrial tachycardia (n = 1, and a heart rate consistently >120 beats/min over 30 mins were randomly assigned to one of three intravenous treatment regimens. Group 1 received diltiazem in a 25-mg bolus followed by a continuous infusion of 20 mg/hr for 24 hrs, group 2 received amiodarone in a 300-mg bolus, and group 3 received amiodarone in a 300-mg bolus followed by 45 mg/hr for 24 hrs. MEASUREMENTS AND MAIN RESULTS: The primary study end point was a >30% rate reduction within 4 hrs. The secondary study end point was a heart rate <120 beats/min (a patient was considered to have uncontrolled tachycardia if heart rate was >120 beats/min 4 hrs after study drug). The primary study end point was achieved in 14/20 (70%), 11/20 (55%), and 15/20 (75%) of patients in groups 1, 2, and 3, respectively (chi2 = 1.95, p =.38). Uncontrolled tachycardia was more frequently observed in group 2 (0/20, 9/29 [55%], and 1/20 [5%] of patients in groups 1, 2, and 3, respectively; chi2 = 17, p =.00016). In patients achieving tachycardia control, diltiazem showed a significantly better rate reduction (p =.0001 group 1 vs. group 3, p =.0001 over time; p =.0001 group 1 vs. group 2, p =.001 over time) when compared with the amiodarone groups. Premature drug discontinuation due to hypotension was required significantly more often in group 1 (6/20 [30%], 0/20, and 1/20 [5%] for groups 1, 2, and 3, respectively; chi2 = 10, p =.01). CONCLUSION: Sufficient rate control can be achieved in critically ill patients with atrial tachyarrhythmias using either diltiazem or amiodarone. Although diltiazem allowed for significantly better 24-hr heart rate control, this effect was offset by a significantly higher incidence of hypotension requiring discontinuation of the drug. Amiodarone may be an alternative in patients with severe hemodynamic compromise.     

胺碘酮治疗老年心房纤颤的疗效及安全性观察

目的 探讨胺碘酮对老年阵发性房颤治疗的效果和安全性.方法 观察分析40例老年阵发性房颤患者胺碘酮治疗的效果和药物副作用.结果 胺碘酮治疗显效率为55 0%,有效率为32 5%,无效率为12 5%;发生甲状腺功能减退 7例,未发生甲状腺功能亢进、肺纤维化、色素沉着.结论 胺碘酮应用于老年人房颤有效、安全,但需密切观察甲状腺功能和对肺的毒性作用.     

Adverse Effects of Amiodarone

Amiodarone was introduced 30 years ago as an antianginal agent and subsequently has been used as an antiarrhythmic agent. This drug was initially used for patients with malignant ventricular arrhythmias; however, currently it is being used broadly for rate and rhythm control in patients with atrial fibrillation. At first, amiodarone was primarily used by cardiologists and today it is used throughout the medical profession. Amiodarone therapy can potentially result in a wide range of adverse effects. The majority of these adverse effects are dose related and reversible. The following is a review of the adverse effects and drug interactions of amiodarone along with recommendations for identification and management of these adverse effects.     

伊布利特治疗预激综合征合并房颤患者的临床疗效观察

[目的]探讨伊布利特治疗预激综合征合并房颤的临床疗效.[方法]回顾性分析2017年2月至2019年6月本院收治的7例预激综合征合并房颤患者,所有患者均给予富马酸依布利特注射液治疗,所有患者在用药后均行预激旁道和(或)房颤射频消融术治疗.观察记录所有患者用药后窦性心律转复情况及手术情况.[结果]7例患者静脉注射伊布利特后...     

胺碘酮对VVI起搏后心房颤动发生率的影响

目的：观察胺碘酮对VVI起搏后心房纤颤发生率的影响。方法；42例植入VVI型起搏器的缓慢型心律失常患者起搏后．分成2组；A组为植入VVI起搏器患者进行常规治疗，共21例；B组为在植入VVI起搏器后，按标准方案给予胺碘酮治疗，共21例。术后所有患者分别于出院后第1、6、12、24、36个月进行随访。结果：A组19例患者达到随访终点，8例（42．1％）发生慢性房颤；B组20例患者达到随访终点，3例（15．0％）发生慢性房颤。结论：胺碘酮对植入VVI型起搏器患者心房颤动的发生有明显的抑制作用。     

围手术期使用胺碘酮对心房颤动转律的研究

目的探讨围手术期使用胺碘酮对二尖瓣置换手术患者心房颤动（房颤）的转复和维持窦性心律的作用。方法40例行二尖瓣置换手术房颤患者随机分为2组：胺碘酮组和安慰剂组，每组20例。胺碘酮组术前3d开始胺碘酮200mg口服，3次／d，术后当天通过微量输液泵持续静脉输注600mg胺碘酮，能进食后改为胺碘酮200mg口服，3次／d；1周后改为200mg口服，2次／d；再1周后改为200mg口服，1次／d，一直维持。安慰剂组以安慰剂代替胺碘酮，服药时间和方法同胺碘酮组。观察2组患者术后房颤转复率、ICU监护时间、住院时间及窦性心律维持情况。结果胺碘酮组房颤转复率明显高于安慰剂组（65％vs30％，P〈0．05）。随访6个月，胺碘酮组维持窦性心律明显优于安慰剂组（70％vs0，P〈0．05），而ICU监护时间和住院时间较安慰剂组缩短[（1．8±1．7）d vs（2．8±1．5）d，（11．3±2，4）d vs（13．4±3．2）d，P均〈0．05]。结论胺碘酮可以有效地将二尖瓣置换手术患者的房颤心律转复为窦性心律，缩短ICU监护时间和住院时间，并且在术后维持窦性心律方面疗效显著。     

胺碘酮联合美托洛尔治疗阵发性心房颤动远期疗效观察

目的:观察胺碘酮联合美托洛尔治疗阵发性心房颤动的远期临床疗效。方法:将收入院的146例阵发性心房颤动患者,随机分成胺碘酮组73例和胺碘酮联合美托洛尔组73例,比较治疗的有效率及不良反应。结果:联合用药组各时期治疗总有效率均高于胺碘酮组,随着时间的延长两组的有效率均下降。结论:胺碘酮联合美托洛尔治疗阵发性心房颤动安全有效。     

Atrial fibrillation after cardiac surgery: evidence on prophylactic interventions

Postoperative atrial fibrillation after heart surgery is frequent and may increase the length of hospital stay and costs of postoperative care of patients after heat surgery. Pharmacological and pacing interventions were evaluated in the large number of relatively small trials with often contradictory results. Conventional β-blockers, sotalol, amiodarone and pacing were shown to be equally effective in the prevention of postoperative atrial fibrillation. Amiodarone and bi-atrial pacing were also effective in decreasing the length of hospital stay.     

Atrial fibrillation after cardiac surgery: evidence on prophylactic interventions

Postoperative atrial fibrillation after heart surgery is frequent and may increase the length of hospital stay and costs of postoperative care of patients after heat surgery. Pharmacological and pacing interventions were evaluated in the large number of relatively small trials with often contradictory results. Conventional beta-blockers, sotalol, amiodarone and pacing were shown to be equally effective in the prevention of postoperative atrial fibrillation. Amiodarone and bi-atrial pacing were also effective in decreasing the length of hospital stay.     

Intravenous amiodarone bolus for treatment of atrial fibrillation in patients with advanced congestive heart failure or cardiogenic shock

BACKGROUND: The clinical course of patients with advanced organic heart disease is often complicated by the occurrence of atrial fibrillation. Slowing the ventricular rate and, if possible, restoration of normal sinus rhythm is crucial but difficult in the state of decreased ventricular function. METHODS: We included 78 consecutive patients with atrial fibrillation and heart rate above 135 beats min(-1) in an observational, uncontrolled study in the coronary care unit of a tertiary care center. Thirty-nine patients suffered from advanced congestive heart failure, 26 patients had pulmonary edema, and 13 patients were in cardiogenic shock. All patients were treated with 450 mg amiodarone given as a single intravenous bolus through a peripheral venous access without further infusion. Ventricular heart rate and cardiac rhythm were measured within 30 minutes after drug administration. Cardiac rhythm was monitored for 24 hours. The site of venous access was examined 30 minutes after drug administration and every 6 hours until the needle was removed after a maximum of 48 hours. RESULTS: Twenty-five patients (32%) converted to normal sinus rhythm within 30 minutes. Another 15 (19%) reverted into sinus rhythm during the following 24 hours. Within 30 minutes after amiodarone administration, ventricular heart rate decreased significantly from 152 +/- 12 to 88 +/- 17 (p < 0.0001) beats min(-1) in patients who converted to sinus rhythm and from 157 +/- 14 to 98 +/- 16 beats min(-1) in patients who did not. The degree of reduction in heart rate was similar among patients presenting with exacerbated congestive heart failure, pulmonary edema, or cardiogenic shock. Systolic blood pressure decreased in two patients, from 115 to 80 mmHg and from 130 to 100 mmHg, but was reversible after 10 and 90 minutes respectively without specific intervention. No proarrhythmia or clinical relevant bradycardia was observed, and no inflammation detected at the site of venous access. CONCLUSIONS: Amiodarone, given as a single intravenous bolus through a peripheral vein rapidly reduced ventricular rate and was well tolerated in patients with atrial fibrillation, even in the presence of congestive heart failure and cardiogenic shock.     

Strategy for cardiac arrhythmias in acute coronary syndrome

Acute coronary syndrome causes several types of arrhythmia because of its electrical instability and ischemia. The most important arrhythmia is ventricular tachycardia which degenerates to ventricular fibrillation. Prompt direct current cardioversion will be needed and prevention of ventricular tachyarrhythmia by potassium channel blocker became more popular in Japan. Nifekalant or amiodarone should be selected. Atrial fibrillation also occurred in the patients with acute coronary syndrome, and it may deteriorate hemodynamics condition. Therefore, termination and prevention of atrial fibrillation is another important issue in acute coronary syndrome. Aprindine, amiodarone, or bepridil will be the choice to prevent recurrent atrial fibrillation after direct current cardioversion.     

Electrical storm: case series and review of management

Electrical storm is defined as a recurrent episode of hemodynamically destabilizing ventricular tachyarrhythmia that usually requires electrical cardioversion or defibrillation. We describe three cases presenting with electrical storm under differing circumstances: (1) a 57-year-old man with ST-elevation myocardial infarction within 1 week of a posterior circulation stroke who developed refractory sustained ventricular tachycardia 10 days after an acute myocardial infarction; (2) a 65-year-old man who developed polymorphic ventricular tachycardia and ventricular fibrillation following dobutamine echocardiography; and (3) a 20-year-old woman who developed intractable ventricular fibrillation following an overdose of a weight-reduction pill. The management of electrical storm is discussed, and evolving literature supporting the routine use of intravenous amiodarone and beta-blockers in place of intravenous lidocaine is critically examined.     

胺碘酮治疗心房颤动

目的：研究胺碘酮治疗心房颤动的疗效。方法：用胺碘酮治疗心房颤动患者68例（阵发性心房颤动40例,持续性心房颤动28例）。结果：连续用药治疗6个月显示治疗有效率分别为92.5%、75%。治疗12个月有效率分别为85.3%、68%。结论：胺碘酮治疗心房颤动安全有效,副作用小,可作为首选药。