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1.
Amiodarone is a benzofuran derivative with a chemical structure similar to thyroxine. Originally introduced to treat angina pectoris, amiodarone was found to have antiarrhythmic properties, and in 1985, was approved in the United States for treatment of life-threatening ventricular arrhythmias. It is now used for various ventricular and supraventricular arrhythmias refractory to conventional first-line medications, and as a result, side effects have been observed with increased frequency. The most severe and potentially life-threatening of these side effects is the development of pulmonary toxicity. Typically, amiodarone pulmonary toxicity (APT) is manifested by acute pneumonitis and chronic fibrosis. Amiodarone-associated hemoptysis (AAH) is a rare occurrence. The authors describe a case of AAH successfully treated with cessation of drug and steroid therapy.  相似文献   

2.
Implantable cardioverter defibrillator (ICD) implantation is rapidly becoming accepted as primary therapy for malignant ventricular arrhythmias. Many patients undergoing ICD implantation are on concomitant antiarrhythmic drugs to decrease shock frequency, slow tachycardia rate, and suppress supraventricular arrhythmias. Amiodarone is a potent antiarrhythmic agent that is also frequently used in the treatment of patients with refractory ventricular arrhythmias. Ten to forty percent of patients undergoing ICD implantation will also be taking amiodarone. It has been reported to cause pulmonary toxicity in about 5% of patients per year. Acute amiodarone toxicity presenting as adult respiratory distress syndrome has been reported much less frequently. Although perioperative morbidity due to amiodarone has been described, the risk, predictability, and consequences of acute pulmonary toxicity from amiodarone in patients undergoing ICD implantation have not been previously described. We reviewed the records of 99 consecutive patients undergoing ICD implantation at our institution from October 1987 to April 1992. Thirty-nine patients were taking 480 +/- 230 mg of amiodarone (median 400 mg, lower 20th percentile 400 mg, upper 80th percentile 800 mg) for 291 +/- 554 days prior to ICD implantation. Ten patients taking amiodarone developed acute pulmonary toxicity clinically manifesting as diffuse pulmonary infiltrates on chest radiography and adult respiratory distress syndrome with hypoxia (arterial pO2 < 60 mmHg) without evidence of pneumonia or elevated pulmonary capillary wedge pressure (PCW < or = 15 mmHg). Of the 60 patients not taking amiodarone none developed adult respiratory distress syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
BACKGROUND: Amiodarone is a commonly used antiarrhythmic agent with complex pharmacological effects. Although ventricular arrhythmias can be suppressed soon after intravenous amiodarone, the mechanisms responsible for this action are unclear. We studied the effects of acute treatment with amiodarone on the metabolism and release of norepinephrine (NE) in intact rats and in perfused rat hearts. METHODS AND RESULTS: Experiments were performed in anesthetized rats and in perfused, innervated hearts with amiodarone administered intravascularly. NE release was induced by electrical stimulation of the sympathetic ganglion. Concentrations of NE and its intraneuronal metabolite dihydroxyphenylglycol (DHPG) in hearts, plasma, and coronary venous effluent were measured by high-performance liquid chromatography. Acute administration of amiodarone induced dose-dependent increases in DHPG concentrations in plasma (5 mg/kg, +48%; 15 mg/kg, +84%; and 50 mg/kg, +467%) and in coronary venous effluent (1 mumol/L, +37%; 3 mumol/L, +510%; and 10 mumol/L, +1100%) together with an unchanged basal overflow of NE. In perfused hearts, NE release evoked by nerve stimulation was inhibited by infusion of amiodarone (1 mumol/L, -16%; 3 mumol/L, -24%; and 10 mumol/L, -64%) or by intravenous amiodarone (50 mg/kg) given 1 hour before heart perfusion (-70%), and the extent of this suppression correlated well with levels of DHPG overflow present immediately before nerve stimulation. When given in vitro and in vivo, amiodarone also significantly reduced NE and increased DHPG content in the heart, leading to a raised DHPG/NE ratio. All these effects of amiodarone were similar to those found with reserpine but less potent. In contrast, oral amiodarone produced none of these effects. CONCLUSIONS: Acute administration of amiodarone in perfused hearts or intact rats induces partial NE depletion in the heart by interfering with vesicular NE storage and enhancing intraneuronal NE metabolism, effects associated with an impaired NE release during sympathetic activation. Oral dosing with amiodarone has no such effect. Further study is required to test whether this novel sympatholytic effect of amiodarone contributes to its antiarrhythmic action after intravenous administration.  相似文献   

4.
OBJECTIVE: The purpose of this study was to analyze the efficacy and safety of intravenous amiodarone in young patients with critical, drug-resistant arrhythmias. BACKGROUND: Intravenous amiodarone has been investigated in adults since the early 1980s. Experience with the drug in young patients is limited. A larger pediatric study group was necessary to provide responsible guidelines for the drug's use before its market release. METHODS: Eight centers obtained institutional approval of a standardized protocol. Other centers were approved on a compassionate use basis after contacting the primary investigator (J.C.P). RESULTS: Forty patients were enrolled. Standard management in all failed. Many patients had early postoperative tachyarrhythmias (25 of 40), with early successful treatment in 21 (84%) of 25. Twelve patients had ventricular tachyarrhythmias: seven had successful therapy, and six died, none related to the drug. Eleven patients had atrial tachyarrhythmias: 10 of 11 had immediate success, but 3 later died. Fourteen patients had junctional ectopic tachycardia, which was treated with success (sinus rhythm or slowing, allowing pacing) in 13 of 14, with no deaths. Three other patients had supraventricular tachycardias, with success in two and no deaths. The average loading dose was 6.3 mg/kg body weight, and 50% of patients required a continuous infusion. Four patients had mild hypotension during the amiodarone bolus. One postoperative patient experienced bradycardia requiring temporary pacing. There were no proarrhythmic effects. Deaths (9 [23%] of 40) were not attributed to amiodarone. CONCLUSIONS: Intravenous amiodarone is safe and effective in most young patients with critical tachyarrhythmia. Intravenous amiodarone can be lifesaving, particularly for postoperative junctional ectopic tachycardia, when standard therapy is ineffective.  相似文献   

5.
Amiodarone is an antiarrhythmic drug widely used to treat a variety of supraventricular and ventricular arrhythmias. However its drawback is a very slow elimination and very frequent adverse effects (thyroid, pulmonary, neurologic, ocular, dermatologic, hepatic disorders). We describe a patient who developed a pseudoalcoholic liver disease and a cirrhosis after use of Amiodarone for a long period of time.  相似文献   

6.
Current antiarrhythmic drug therapy is employed in strict compliance with the proper indication, which is itself limited by the side effects of the available drugs, and modified by the increasing success of such non-drug options as electrical ablation and implantable cardioverters/defibrillators. Drug treatment is restricted to 3 major indications, regular paroxysmal supraventricular tachycardias, atrial flutter and fibrillation, and ventricular tachycardias. Class IA and IC agents are used only to treat supraventricular and ventricular arrhythmias with no structural heart disease. Class III drugs, e.g. sotalol and in particular amiodarone are used preferentially to treat the pre-damaged heart, in particular left-ventricular functional impairment and in coronary heart disease in consideration of their side effects. In the case of the most common treatment-requiring arrhythmia-atrial fibrillation-anticoagulation alone may be indicated. For the prevention of sudden death, beta-blockers continue to be the drugs of first choice.  相似文献   

7.
Amiodarone is a choice drug for the treatment of patients suffering from life-threatening hyperkinetic ventricular arrhythmias and depressed ventricular function. The drug is characterized by a remarkably long halflife and a delayed initial activity after oral administration of the usual loading levels. The aim of this study was to establish: -the clinical tolerance to elevated doses in patients with heart failure presenting complex, hyperkinetic ventricular arrhythmias; -the possibility to shorten hospitalization as a result of the oral loading; -whether this administration route would take less time to be efficacious. For this purpose, 30 patients with heart failure and complex, hyperkinetic ventricular arrhythmias were treated with 0.50 mg/kg body weight of amiodarone for three days and with 0.30 mg/kg on the 4th and 5th days, followed by a maintenance period of treatment with 200-400 mg daily. All patients underwent a 24-h Holter test before and after administration and an echocardiographic examination showing an average ejection fraction of approximately 30%. Amiodarone was clinically well tolerated; only 2 patients required discontinuation of therapy whereas, among the the remaining 28 patients, 2 cases of transient hypotension and 3 cases of gastroenteric disorders were observed. It was concluded that elevated doses of amiodarone were well tolerated, which allowed to reduce the loading period and, therefore, hospitalization.  相似文献   

8.
Amiodarone hydrochloride, a new antiarrhythmic agent, controlled a recurrent supraventricular arrhythmia, refractory to conventional medical treatment, in a 57-year-old patient with an anomalous conduction system and idiopathic cardiomyopathy. For the 11 months that the patient has been taking the drug her arrhythmia has not recurred. This drug has produced no important side effects in this patient.  相似文献   

9.
Control of heart rate in critically ill patients who develop atrial fibrillation or atrial flutter can be difficult. Amiodarone may be an alternative agent for heart rate control if conventional measures are ineffective. We retrospectively studied intensive care unit patients (n = 38) who received intravenous amiodarone for heart rate control in the setting of hemodynamically destabilizing atrial tachyarrhythmias resistant to conventional heart rate control measures. Atrial fibrillation was present in 33 patients and atrial flutter in 5 patients. Onset of rapid heart rate (mean 149 +/- 13 beats/min) was associated with a decrease in systolic blood pressure of 20 +/- 5 mm Hg (p <0.05). Intravenous diltiazem (n = 34), esmolol (n = 4), or digoxin (n = 24) had no effect on heart rate, while reducing systolic blood pressure by 6 +/- 4 mm Hg (p <0.05). The infusion of amiodarone (242 +/- 137 mg over 1 hour) was associated with a decrease in heart rate by 37 +/- 8 beats/min and an increase in systolic blood pressure of 24 +/- 6 mm Hg. Both of these changes were significantly improved (p <0.05) from onset of rapid heart rate or during conventional therapy. Beneficial changes were also noted in pulmonary artery occlusive pressure and cardiac output. There were no adverse effects secondary to amiodarone therapy. Intravenous amiodarone is efficacious and hemodynamically well tolerated in the acute control of heart rote in critically ill patients who develop atrial tachyarrhythmias with rapid ventricular response refractory to conventional treatment. Cardiac electrophysiologic consultation should be obtained before using intravenous amiodarone for this purpose.  相似文献   

10.
Many patients with an implanted cardioverter defibrillator (ICD) also receive antiarrhythmic drug therapy. Although an expanding number of patients are receiving ICD therapy, many will not have received previous antiarrhythmic treatment. For patients with an ICD, infrequent arrhythmias and a low probability of inappropriate device discharges, no antiarrhythmic therapy is required. However, for those patients who require an antiarrhythmic drug, amiodarone is a reasonable first choice because of safety in patients with poor LV function. It may be particularly useful for patients with high density ventricular arrhythmias. However, the interactions between ICDs and antiarrhythmic therapy requires close monitoring in order that patient benefit can be optimised, and this review focuses on those interactions.  相似文献   

11.
OBJECTIVE: Amiodarone, a class III antiarrhythmic agent, is a potent coronary vasodilator. However, direct evidence for its vasodilatory effects in human vasculature in vivo is not available. The aim of the study was to investigate the short-term effects of amiodarone in preconstricted human hand veins and to explore the underlying mechanisms. METHODS: Thirty-one healthy male volunteers were studied with the use of the dorsal hand vein compliance technique. The hand veins of the subjects were preconstricted with the alpha 1-adrenergic receptor agonist phenylephrine, and amiodarone, inhibitors of nitric oxide formation (NG-monomethyl-L-arginine, L-NMMA), and adenosine triphosphate-dependent potassium channels (glyburide [INN, glibenclamide]) were infused in the presence or absence of a cyclooxygenase inhibitor (acetylsalicylic acid), and the venodilator effect was measured. Furthermore, amiodarone was infused in prostaglandin F2 alpha (dinoprost)-preconstricted hand veins. RESULTS: Amiodarone produced dose-dependent venodilation (51% +/- 3% maximum). Maximum amiodarone-induced venodilation was lower in dinoprost compared with phenylephrine-preconstricted veins. Pretreatment with acetylsalicylic acid reduced the amiodarone-induced venodilation by 40% +/- 6%. L-NMMA reduced the amiodarone-induced venodilation after pretreatment with acetylsalicylic acid by 72% +/- 3%. Glyburide decreased the venodilatory response of amiodarone by 31% +/- 11%, whereas only a slight but not statistically significant additional reduction in venodilation was detected after pretreatment with acetylsalicylic acid. Infusion of the solvents of commercially available amiodarone (polysorbate 80 and benzyl alcohol) did not cause vasodilation in phenylephrine-preconstricted veins. CONCLUSIONS: Amiodarone dilates preconstricted human hand veins in vivo and acts as a venodilator through the cyclooxygenase pathway, activation of nitric oxide synthase, and blockade of alpha adrenergic mechanisms.  相似文献   

12.
This study assessed the cost effectiveness of inpatient antiarrhythmic therapy initiation for supraventricular tachycardias using a metaanalysis of proarrhythmic risk and a decision analysis that compared inpatient to outpatient therapy initiation. A MEDLINE search of trials of antiarrhythmic therapy for supraventricular tachycardias was performed, and episodes of cardiac arrest, sudden or unexplained death, syncope, and sustained or unstable ventricular arrhythmias were recorded. A weighted average event rate, by sample size, was calculated and applied to a clinical decision model of therapy initiation in which patients were either hospitalized for 72 hours or treated as outpatients. Fifty-seven drug trials involving 2,822 patients met study criteria. Based on a 72-hour weighted average event rate of 0.63% (95% confidence interval, 0.2% to 1.2%), inpatient therapy initiation cost $19,231 per year of life saved for a 60-year-old patient with a normal life expectancy. Hospitalization remained cost effective when event rates and life expectancies were varied to model hypothetical clinical scenarios. For example, cost-effectiveness ratios for a 40-year-old without structural heart disease and a 60-year-old with structural heart disease were $37,510 and $33,310, respectively, per year of life saved. Thus, a 72-hour hospitalization for antiarrhythmic therapy initiation is cost effective for most patients with supraventricular tachycardias.  相似文献   

13.
The Cardiac Arrest in Seattle, Conventional Versus Amiodarone Drug Evaluation (CASCADE) study evaluated antiarrhythmic drug therapy in high-risk survivors of out-of-hospital ventricular fibrillation. Antiarrhythmic drug therapy for 228 patients was randomized to amiodarone or conventional antiarrhythmic drugs. Additional therapy with an implantable cardioverter-defibrillator was provided to 105 of these patients. Clinical predictors of shocks were evaluated for the 88 patients with coronary artery disease (amiodarone 46, conventional 42), treated with an implantable cardioverter-defibrillator. Survival free of all shocks at 2 years was 77% for patients taking amiodarone and 42% for those receiving conventional therapy (p = 0.014). Two-year survival free of syncopal shocks was 98% for amiodarone-treated patients and 81% for those receiving conventional agents (p = 0.01). Multiple clinical factors were evaluated by Cox analysis for potential clinical predictors of shocks. The independent clinical predictors of shocks were low ejection fraction (p = 0.002), female gender (p = 0.007) and conventional antiarrhythmic drug therapy (p = 0.015). The only independent predictor of a shock associated with syncope was conventional antiarrhythmic drug therapy (p = 0.035). Patients treated with amiodarone receive fewer shocks than patients treated with conventional drug therapy.  相似文献   

14.
Antiarrhythmic drug prophylaxis in patients with atrial fibrillation (AF) is associated with a high incidence of arrhythmic recurrence. Uncontrolled studies have suggested that low-dose amiodarone may be superior in terms of efficacy to other antiarrhythmic drugs while having an acceptable side effect profile. The Canadian Trial of Atrial Fibrillation (CTAF) is a 25-center study sponsored by the Medical Research Council of Canada to determine the best treatment strategy to maintain sinus rhythm in patients with persistent or paroxysmal AF. Recruitment began in November 1996 and will continue for 1.5 years. Patients are randomized to receive either low-dose amiodarone or conventional antiarrhythmic drug therapy. Patients assigned to the amiodarone group will receive an oral loading regimen of 10 mg/kg/day during a minimum 14-day period. Patients assigned to conventional antiarrhythmic therapy will receive 1 of 2 agents commonly used in AF prophylaxis: sotalol or propafenone. Drug selection and loading, and electrical cardioversion, if necessary, will be performed within 21 days of randomization. The long-term maintenance dose of amiodarone is 200 mg/day. We have planned a minimum follow-up period of 1 year. The primary end point is the time to the first relapse of AF. Data will be analyzed on an intention-to-treat basis. Secondary outcomes are medication toxicity, mortality, major clinical events, costs of each approach, and quality of life. For the purpose of sample size calculations, it is anticipated that recurrence of AF at 1 year will occur in 50% of patients on conventional treatment compared with 35% in those receiving amiodarone. In order to have an 80% power and a 2-tailed type I error of 0.05, assuming a 15% loss to follow-up rate, a total sample size of 400 patients will be required. A pilot study done at the Montreal Heart Institute has shown that the research protocol is feasible.  相似文献   

15.
OBJECTIVE: To review evaluation and treatment of patients with ventricular arrhythmias, based on recent studies, with an emphasis on randomized controlled trials. DATA SOURCES: MEDLINE search of English-language publications of ventricular arrhythmias and their references from 1966 through April 27, 1998. References to articles were also scanned to broaden the search. STUDY SELECTION: Randomized controlled trials and all large nonrandomized trials of arrhythmias and arrhythmia therapy were reviewed. In addition, studies that led to changes in approach to patients with arrhythmias were reviewed. DATA EXTRACTION: We reviewed articles jointly for pertinent studies and information. DATA SYNTHESIS: The goals of treatment of the patient with ventricular arrhythmias are to suppress symptoms and prevent a fatal event. The steps in providing such therapy include defining the cardiac anatomy, assessing arrhythmia risk through noninvasive or invasive testing, and prescribing treatment based on these results. Patients may be separated into high- and low-risk groups to help identify appropriate treatment. While low-risk groups may benefit from reassurance or medications such as beta-blockers or verapamil, high-risk groups have been more difficult to treat. Recent randomized trials of implantable cardioverter defibrillators for ventricular arrhythmias suggest that they may provide better protection for high-risk patients than do antiarrhythmic medications. CONCLUSIONS: Treatment and understanding of risk from ventricular arrhythmias have advanced substantially in recent years. Classifying patients as being at high or low risk for fatal arrhythmias allows the physician to identify appropriate treatments for the high-risk patient without exposing the low-risk patient to unnecessary treatment-related risks.  相似文献   

16.
Procainamide remains one of the most widely used antiarrhythmic agents in clinical practice. Currently, it is widely used alone or in combination with class I agents (eg, mexiletine or tocainide) to prevent recurrent ventricular tachycardia or symptomatic nonsustained ventricular tachycardia. Procainamide is also used for short-term treatment of ventricular tachycardia and a variety of supraventricular tachycardias, primarily atrial flutter and atrial fibrillation. Long-term procainamide therapy is limited by a number of systemic side effects, primarily lupus-like syndrome, gastrointestinal disturbances, and autoimmune blood dyscrasias. Procainamide levels can be useful in initial dose titrations; however, QRS and QT interval measurements help prevent drug toxicity. It is recommended that patients being started on antiarrhythmic therapy with procainamide be admitted to the hospital for monitoring to ensure that their QT interval is not excessively prolonged.  相似文献   

17.
PURPOSE: To assess the incidence of amiodarone-mediated aggravation of ventricular tachyarrhythmias or the development of new arrhythmias, such as torsade de pointes, in patients with cardiac disease. DATA SOURCES AND STUDY SELECTION: A MEDLINE literature search was done to identify articles published during the last 20 years that presented data on amiodarone-associated proarrhythmic events. The articles were divided into three categories: case reports, uncontrolled retrospective studies, and prospective controlled trials. In addition, articles were identified that examined the effects of amiodarone in patients with previously documented drug-induced torsade de pointes. RESULTS: 65 English-language case reports dealing with torsade de pointes during amiodarone therapy were found in the literature. In many of these cases, other predisposing factors for the development of torsade de pointes were reported. Seventeen studies each reported data from at least 50 patients who were treated with amiodarone for at least 6 months. Of 2878 patients included in these trials, 57 were reported to have a proarrhythmic event while exposed to the drug (an overall incidence of 2%). Torsade de pointes was observed in one third of these patients (an overall incidence of 0.7%). In seven placebo-controlled trials in which the drug was given as monotherapy, amiodarone was not associated with the development of a proarrhythmic event in any patient. Finally, in three reports, 31 patients with previous drug-mediated torsade de pointes were exposed to amiodarone during short- and long-term therapy. In none of these patients did a recurrent episode of torsade de pointes develop, despite the amiodarone-induced prolongation of the QTc interval, which was equivalent to that observed at the time of torsade de pointes during exposure to previous drugs. CONCLUSIONS: Amiodarone appears to be associated with a remarkably low frequency of proarrhythmic events and an incidence of torsade de pointes of less than 1.0%. This low arrhythmogenicity and the negligible negative inotropic effect of the compound constitute properties that make amiodarone particularly useful in treating high-risk patients prone to sudden cardiac death. Its potential to reduce this risk is currently being evaluated in several large prospective trials.  相似文献   

18.
Drug therapy has traditionally been the mainstay of treatment for both ventricular and supraventricular arrhythmias. However, increasing knowledge about the potentially significant adverse effects of these medications, together with the emergence of new, nonpharmacological approaches to the treatment of arrhythmias, has led some to question the future of antiarrhythmic drug therapy. Antiarrhythmic drugs are quite effective in terminating a variety of arrhythmias, including atrioventricular (AV) node re-entrant and AV tachycardias (particularly calcium antagonists and adenosine), atrial flutter (class III agents) and atrial fibrillation (class IA and IC drugs. The chronic use of antiarrhythmic drugs has been increasingly limited by a fear of adverse effects (especially proarrhythmia) and the availability of highly effective nonpharmacological alternatives (particularly ablation for re-entrant tachycardias involving the AV node and bypass tracts and cardiovertor/defibrillators for malignant ventricular arrhythmias. Atrial fibrillation (AF) continues to be a therapeutic challenge for which there is no safe and curative nonpharmacological therapy. Antiarrhythmic drugs of classes IA, IC and III show efficacy in preventing recurrence of AF but there are concerns about possible pro-arrhythmic complications. In the future, antiarrhythmic agents will continue to be used acutely to terminate a broad range of sustained arrhythmias. Chronic use is likely to depend on the development of safer and/or more effective compounds, as well as on improved ways of predicting which patients are likely to develop pro-arrhythmic reactions. The development of molecular electrophysiology will allow for the identification of agents with selected ion channel blocking profiles which may prove efficacious with a lower risk of complications. Finally, an improved understanding of arrhythmia substrates may permit the identification of therapy that prevents arrhythmias by acting on the underlying substrate, rather than simply trying to modify the electrical end product.  相似文献   

19.
A 72 year old white man developed acute hepatic impairment and renal failure within 24 hours of starting intravenous amiodarone for paroxysmal ventricular tachycardia. After normal initial investigations, there was a noticeable rise in serum transaminases as well as an increase in clotting times, a decrease in renal function and a thrombocytopenia. These changes returned to normal within seven days of withdrawal of the drug without specific treatment, and the patient was later treated with oral amiodarone without any further evidence of hepatotoxicity. Intravenous amiodarone has been implicated in acute hepatic disease on four previous occasions, but it is suggested that polysorbate 80, an organic surfactant added to the intravenous infusion, is a more likely cause of this complication. Similar reactions have been described with polysorbate 80 in association with the 'E-ferol' syndrome in infants. The occurrence of acute hepatic impairment with intravenous amiodarone does not necessarily preclude the use of this drug by mouth.  相似文献   

20.
We report a case of pulmonary fibrosis in an infant receiving amiodarone for treatment of intractable atrioventricular reentrant tachycardia secondary to Wolff-Parkinson-White syndrome. At 9 months, a screening chest radiograph showed a diffuse interstitial infiltrate in an asymptomatic, thriving infant. Amiodarone was discontinued and the pulmonary fibrosis resolved gradually over 6 months. This case documents the first report of amiodarone induced pulmonary fibrosis in the pediatric age group. We speculate that as amiodarone is used more frequently to manage pediatric arrhythmias, pulmonary fibrosis, a known complication of this antiarrhythmia in adults may be seen with increasing frequency in children.  相似文献   

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