Efficacy, Safety, and Determinants of Conversion of Atrial Fibrillation and Flutter With Oral Amiodarone

doi:10.1016/S0002-9149(96)00675-3

The American Journal of Cardiology

Volume 79, Issue 1, 1 January 1997, Pages 53-57

https://doi.org/10.1016/S0002-9149(96)00675-3 Get rights and content

Abstract

Amiodarone is effective for long-term maintenance of sinus rhythm after electrical cardioversion of refractory atrial fibrillation or flutter. To examine its efficacy and safety for pharmacologic conversion of these arrhythmias, we studied 129 patients with refractory atrial fibrillation or flutter who had failed previous intensive conventional antiarrhythmic treatment. In anticipation of electrical cardioversion, patients were loaded with amiodarone, 600 mg/day during a 4-week period. The main outcome measure was pharmacologic conversion during this period. During the loading period, 23 patients (18%) converted to sinus rhythm. When analyzed in a multivariate model, conversion was related to desethylamiodarone plasma level (p = 0.0006), arrhythmia duration (p = 0.04), left atrial area (p = 0.02), and concomitant treatment with verapamil (p = 0.01). During ongoing atrial fibrillation after loading, the ventricular rate decreased from 100 ± 25 to 87 ± 27 beats/min (p < 0.001). Amiodarone appeared to be safe and did not have to be discontinued because of intolerable side effects. Thus, amiodarone loading is safe and is still able to convert refractory atrial fibrillation or flutter. Conversion is related to increased desethylamiodarone plasma levels and concomitant treatment with verapamil. Because prolonged loading may increase desethylamiodarone plasma concentrations, this may enhance efficacy and obviate the need for electrical cardioversion.

Section snippets

Patients

One hundred twenty-nine consecutive patients with chronic atrial fibrillation or flutter were considered candidates for preparatory amiodarone treatment in anticipation of electrical cardioversion. Eighty-nine of these patients participated in a study described previously.[1] Criteria for prophylactic treatment with amiodarone were also described previously by Crijns et al.[2] In short, amiodarone was administered only as a “last resort” drug in patients who failed to maintain sinus rhythm

Results

During an amiodarone loading phase of 30 ± 3 days, patients received a mean total dose of 18 ± 2 g. Twenty-three patients (18%) converted to sinus rhythm, whereas the remaining 106 patients were still in atrial fibrillation or flutter after this period. The latter patients underwent subsequent electrical cardioversion, which was successful in 92 (87%). QRS duration increased from 96 ± 18 ms to 105 ± 20 ms (p <0.001). QT and QT_c intervals increased from 372 ± 46 to 409 ± 45 ms (p < 0.001) and

Discussion

The importance of amiodarone for long-term arrhythmia outcome after cardioversion of atrial fibrillation or flutter is well known.1, 5, 6, 7, 8, 9, 10 Amiodarone is also useful for pharmacologic conversion of atrial fibrillation, with success rates ranging from 27% to as high as 86%,6, 7, 8, 9, 11, 12, 13 depending upon patient characteristics and drug administration. The present study showed that even in a highly selected group of patients refractory to antiarrhythmic treatment, amiodarone was

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Therapeutic monitoring of amiodarone and desethylamiodarone after surgical ablation of atrial fibrillation-evaluation of the relationship between clinical effect and the serum concentration
2021, Saudi Pharmaceutical Journal
Association between clinical effect and serum concentration of amiodarone (AMI) and its active metabolite desethylamidarone (DEA) in patients after surgical ablation (SA) of atrial fibrillation (AF) has not yet been studied.
We wanted to find a correlation between AMI and DEA serum concentration and maintaining sinus rhythm (SR) after SA of AF.
Sixty eight patients with AF who had undergone surgical ablation between 2014 and 2017 were included in a single-centre, prospective, observational study. Maintaining of SR was evaluated by standard 12-lead ECG and 24-hour Holter ECG monitoring at months 1, 3, 6 and 12 following surgery. Therapeutic monitoring of AMI and DEA concentrations was done to optimize therapy and adverse effects were followed up.
We have noticed a high success rate in maintaining of SR (overall 83%). The median of serum concentration of AMI was 0.81 mg/L (range 0.16–2.35 mg/L) and DEA 0.70 mg/l (range 0.19–2.63 mg/L). No significant differences were found in the serum concentratration of AMI, DEA or DEA/AMI concentratration ratios between patients with SR and persistent supraventricular tachyarrhythmia except on the second outpatient visit. We observed significant correlation between serum concentration of DEA and thyroid-stimulating hormone elevation.
We confirmed the efficacy of AMI and DEA at the measured serum concentrations. However, analysis of these concentrations alone cannot replace assessment of the clinical response for treatment. Establishment of individual AMI (and DEA) concentrations at which the optimal therapeutic response is achieved seems to be advantageous. Therapeutic monitoring of AMI and DEA is helpful in personalised pharmacotherapy after SA of AF.
A new score for detection of early cardioversion using intravenous amiodarone in recent onset atrial fibrillation
2016, Egyptian Heart Journal
Amiodarone is the only available intravenous antiarrhythmic medication in Egypt used in acute AF cardioversion. Cardioversion using IV amiodarone takes 6–8 h, and can be as late as 16 h. The aim of this study was to identify the clinical factors that are most associated with early (<8 h) successful pharmacological cardioversion of AF, and use them to construct a weighted scoring system, that can help in deciding which patient to start with electric cardioversion to reduce time and cost of hospital stay.
The study included 83 consecutive patients; with first attack, recent onset AF lasting less than 48 h. The patients were divided into a study group (60 patients), and a validation group (23 patients). The study group patients were divided into Group A (cardioverted in less than 480 min), and group B (cardioverted at 480 min or more), and different clinical and echocardiographic data were collected and compared between the two groups. Relevant variables were entered in forward binary logistic regression analysis, and weighted score was constructed. The score was validated on the validation group.
A 7 variable scoring system was constructed as follows: LA diameter <3.35 cm 6 points, no significant MR 4 points, no history of DM 3 points, mean BP on presentation below 95 mmHg 3 points, presentation before 225 min of onset of symptoms 2 points, no history hypertension 1 point and no diastolic dysfunction 1 point, with final total score = 20 points. A ROC analysis was performed for the scored patients showing that all patients scoring 12 points or more are most likely to convert early with a sensitivity of 89.5% and a specificity of 92.7%, P < 0.0001. Score validation revealed sensitivity, specificity, and accuracy for detection of early cardioversion of 80%, 88% and 83%, P = 0.006 respectively.
The current study suggested a weighted scoring system, to predict the time to cardioversion in patients with recent onset first presentation with atrial fibrillation.
Atrial fibrillation
2012, Cardiovascular Therapeutics: A Companion to Braunwald's Heart Disease: Fourth Edition
Role of oral amiodarone in patients with atrial fibrillation and congestive heart failure
2011, Journal of Cardiology
Amiodarone is recognized as the most effective therapy for maintaining sinus rhythm (SR) post cardioversion in patients with atrial fibrillation (AF). It is also recommended for controlling AF in patients with congestive heart failure (CHF). We retrospectively examined the efficacy and safety of oral amiodarone in patients with AF and CHF.
Forty-eight consecutive AF patients whose left ventricular ejection fraction (LVEF) was less than 50% and B-type natriuretic peptide (BNP) was higher than 100 pg/ml were investigated retrospectively, and divided into 3 groups: paroxysmal AF, 16 patients; persistent AF, 9 patients; and permanent AF, 23 patients.
The permanent AF group had a longer history of AF, larger left ventricular end-diastolic diameter (LVDd) and left atrial diameter (LAD) than paroxysmal and persistent AF groups (p < 0.05). After median follow-up of 265 days, amiodarone suppressed paroxysms in 88% of paroxysmal AF patients, while SR was maintained in all persistent AF patients, and 35% of permanent AF patients. Of the 32 persistent and permanent AF patients, 12 (71%) out of 17 maintained SR after successful electrical cardioversion, and conversion to SR occurred spontaneously in 5 (33%) out of 15. The effective group had significantly smaller LVDd and LAD than the ineffective group. In the effective group, BNP decreased significantly from 723 ± 566 pg/ml to 248 ± 252 pg/ml, (p < 0.0005) and LVEF increased significantly from 33 ± 7% to 50 ± 13% (p < 0.0005) during follow up, while no changes were observed in the ineffective group. The patients with low LVEF (≤30%) benefited comparably from amiodarone to the patients with LVEF >30%. Complications occurred in 24 (50%) patients leading to discontinuation of amiodarone in 11 (23%).
Oral amiodarone helped restore SR in paroxysmal and persistent AF patients with CHF. The successful rhythm control by amiodarone resulted in the improvement of LV function and the decrease of BNP levels.
2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines Developed in partnership with the European Society of Cardiology and in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society
2011, Journal of the American College of Cardiology
Citation Excerpt :
The major concern is the potential for serious adverse effects, including torsades de pointes (Table 21). With the exception of those involving low-dose oral amiodarone (533), virtually all studies of pharmacological cardioversion have involved hospitalized patients. However, one study (627) provided a clinically useful approach with out-of-hospital patient-controlled conversion using class IC drugs (see Tables 6, 7, and 8).
Incidence of early adverse events surrounding direct current cardioversion of persistent atrial fibrillation. A cohort study of practices
2007, Therapie
To establish the incidence of early adverse events surrounding direct current (DC) cardioversion of persistent atrial fibrillation in an unselected patient cohort and to describe and analyse these complications.
Prospective study over a three-month period (February, March and April 2000). Outcome measures included all serious adverse events during the hospitalisation for DC cardioversion. Six hundred and eighty-four DC cardioversion were performed on 659 patients.
The rate of adverse events was 4.4% including 1.3% bradycardia, 0.3% ventricular arrhythmia, 0.3% QT increase, 1% serious haemorrhages, 0.4% death and 1.2% miscellaneous adverse events.
The perceived tolerance to DC cardioversion in atrial fibrillation should be amended with the 4.4% serious early adverse events.
Connaître l’incidence des évènements indésirables précoces survenant à l’occasion de la cardioversion électrique externe (CEE) de la fibrillation atriale dans une population non sélectionnée, décrire et analyser ces évènements.
Etude prospective sur une période de trois mois (février, mars et avril 2000). Tous les évènements indésirables graves survenus au cours de l’hospitalisation pour la CEE ont été relevés. Pendant la période de l’étude 684 CEE ont été réalisées chez 659 patients.
L’incidence des évènements indésirables a été de 4,4 % comportant 1,3 % de bradycardies, 0,3 % de troubles du rythme ventriculaires, 0,3 % d’allongement de l’intervalle QT, 1 % d’hémorragies sévères, 0,4 % de décès et 1,2 % d’évènements indésirables divers.
La réputation de bonne tolérance de la CEE pour fibrillation atriale mérite d’être modulée par le chiffre de 4,4 % d’évènements indésirables précoces graves.

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Efficacy, Safety, and Determinants of Conversion of Atrial Fibrillation and Flutter With Oral Amiodarone

Abstract

Section snippets

Patients

Results

Discussion

Am J Cardiol

Am J Cardiol

Am Heart J

J Am Coll Cardiol

Am J Cardiol

Am J Cardiol

Am J Cardiol

J Am Coll Cardiol

Prog Cardiovasc Dis

J Am Coll Cardiol

J Am Coll Cardiol

Am J Med

Am J Cardiol

Am J Cardiol