Oral loading with propafenone for conversion of recent-onset atrial fibrillation: a review on in-hospital treatment

Effectiveness of a Triple Antiarrhythmic Drug Strategy for Arrhythmia Recurrence after Persistent Atrial Fibrillation Ablation

BACKGROUND AND OBJECTIVE

Treating recurrent atrial arrhythmias after persistent atrial fibrillation (PeAF) ablation is often challenging. This single-center, prospective study aimed to observe the effectiveness of different combinations of oral antiarrhythmic drugs (AADs) in reverting to sinus rhythm (SR) in patients with recurrent atrial arrhythmias after PeAF ablation.

METHODS

Forty-five patients who experienced recurrent atrial arrhythmias after PeAF ablation were included. Based on their medication regimens, patients were divided into two groups, with the study group being a triple-drug group (digoxin combined with amiodarone/ propafenone and β-blocker), and the control group being a non-triple-drug group.

RESULTS

The rate of reversion to SR was significantly higher in the study group (n = 29) than in the control group (n = 16) at 3 weeks (34.48% vs. 0%, p < 0.01) and 1 month (44.84% vs. 6.25%, p = 0.02) after initiating AADs. No patients with asymptomatic bradycardia were observed in either group.

CONCLUSIONS

For patients with recurrent atrial arrhythmias after PeAF ablation, a regimen of low-dose digoxin combined with amiodarone/propafenone and β-blocker may effectively improve short-term reversion rates.

Meta‑analysis of the efficacy and safety of nifekalant in the conversion of atrial fibrillation

Atrial fibrillation (AF) is the most common type of supraventricular tachyarrhythmia. Nifekalant is a new class III antiarrhythmic drug approved for the treatment of ventricular tachyarrhythmias, but its effectiveness in converting AF to sinus rhythm remains unclear. The present analysis aimed to investigate the effect of nifekalant in the conversion of AF. PubMed, Cochrane Library and China National Knowledge Infrastructure databases were systematically used to search relevant studies published between 1999 (data at which the drug was first approved for marketing in Japan) and 2022. Randomized clinical trials, prospective studies and retrospective studies on the use of nifekalant for AF were screened. The study metrics included the success rate of the conversion of AF, the mean time to conversion, the success rate of 12 months after a single AF catheter ablation procedure and the incidence of adverse events. The eligible studies screened included six randomized clinical trials, three prospective studies and three retrospective studies, totalling 12 studies with 1,162 patients. The risk ratio (RR) for successful conversion in the nifekalant and control groups was 1.95 [95% confidence interval (CI), 1.23-3.08; P=0.005] and the mean difference for the mean time to conversion was -1.73 [95% CI, -2.69-(-0.77); P=0.0004]. Statistically significant differences were observed between nifekalant and control groups. Subgroup analysis revealed a statistically significant difference in the success rate of conversion following catheter ablation in the nifekalant group compared with the amiodarone group and the RR value was 1.95 (95% CI, 1.37-2.77; P=0.0002). Statistically significant difference was observed compared with the electrical cardioversion group and the RR value was 0.90 (95% CI, 0.84-0.98; P=0.01). However, the combined RR values for the two groups were 1.18 (95% CI, 0.85-1.65; P<0.0002). The RR value for adverse events was 0.85 (95% CI, 0.51-1.43; P=0.55), with no statistically significant differences between nifekalant and control groups. In conclusion, the results demonstrated that the success rate and time to conversion in the nifekalant group were improved compared with those in the control group, particularly after catheter ablation, and the conversion effect with nifekalant was significantly improved compared with that in the control group.

Comparison of the efficacy and safety of different doses of nifekalant in the instant cardioversion of persistent atrial fibrillation during radiofrequency ablation

Nifekalant has been used in the treatment of atrial arrhythmia recently. However, there is no consensus on the preferable nifekalant dose to treat atrial fibrillation (AF). The purpose of this study was to explore efficacy and safety of different doses of nifekalant in the cardioversion of persistent AF. The study was a single-centre, randomized controlled trial. All subjects received nifekalant or placebo intravenously, and the nifekalant was given at the dosage of 0.3, 0.4 or 0.5 mg/kg. Primary efficacy end-point: compared with 0.3 mg group, the rate of cardioversion to sinus rhythm from AF in 0.4 and 0.5 mg group was higher. The 0.4 and 0.5 mg/kg doses were associated with a similar magnitude of efficacy (P > .05). Secondary efficacy end-point: termination rates of AF in the group of 0.4 mg and 0.5 mg were higher than 0.3 mg. Primary safety end-point: the rate of Torsades de Pointes or ventricular fibrillation was numerically lower in the 0.4 mg group than 0.5 mg group (P = .02). Secondary safety end-point: The rates of the majority of other common drug-related adverse events in the group of 0.5 and 0.4 mg were higher than the 0.3 mg group. A 0.4 mg/kg dose of intravenous nifekalant may be recommended during the radiofrequency ablation for persistent AF considering the benefit-risk profile.

Emergency Department Management of Recent-Onset Atrial Fibrillation

Atrial fibrillation (AF) is the most common tachyarrhythmia managed in the emergency department (ED). Visits to the ED for a presentation of AF have been increasing in recent years, with an admission rate that exceeds 60% in the United States and contributes substantially to health care costs. Recent-onset AF-defined as symptom onset less than 48 hr-is a common ED presentation for which rate control or acute electrical or pharmacological cardioversion may be appropriate treatment modalities depending on patient-specific circumstances. The focus of this review is to discuss the current recommendations regarding the management of recent-onset nonvalvular AF in the ED, discuss medication administration considerations, and identify implementation strategies in the ED to optimize throughput and reduce hospital admissions.

Early experience with intravenous sotalol in children with and without congenital heart disease

BACKGROUND

Arrhythmias are common in the pediatric population. In patients unable to take oral medications or in need of acute therapy, options of intravenous (IV) antiarrhythmic medications are limited. Recently IV sotalol has become readily available, but experience in children is limited.

OBJECTIVE

The purpose of this study was to describe our initial experience with the use of IV sotalol in the pediatric population.

METHODS

A retrospective study of all pediatric patients receiving IV sotalol was performed. Patient demographic characteristics, presence of congenital heart disease, arrhythmia type, efficacy of IV sotalol use, and adverse effects were evaluated.

RESULTS

A total of 47 patients (26 (55%) male and 24 (51%) with congenital heart disease) received IV sotalol at a median age of 2.05 years (interquartile range 0.07-10.03 years) and a median weight of 12.8 kg (interquartile range 3.8-34.2 kg), and 13 (28%) received IV sotalol in the acute postoperative setting. Supraventricular arrhythmias occurred in 40 patients (85%) and ventricular tachycardia in 7 (15%). Among 24 patients receiving IV sotalol for an active arrhythmia, acute termination was achieved in 21 (88%). Twenty-three patients received IV sotalol as maintenance therapy for recurrent arrhythmias owing to inability to take oral antiarrhythmic medications; 19 (83%) were controlled with sotalol monotherapy. No patient required discontinuation of IV sotalol secondary to adverse effects, proarrhythmia, or QT prolongation.

CONCLUSION

IV sotalol is an effective antiarrhythmic option for pediatric patients and may be an excellent agent for acute termination of active arrhythmias. It was well tolerated, with no patient requiring discontinuation secondary to adverse effects.

Antiarrhythmic drugs for atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is associated with increased mortality and morbidity. Although stroke prevention is the only way to improve prognosis, antiarrhythmic drugs (AADs) are of primary importance both in the conversion to sinus rhythm and in the long-term control of rhythm and rate.

AREAS COVERED

We searched the Cochrane Library and Medline Database for articles published in English concerning efficacy and safety of AADs in AF. Particular attention was paid to the recently published European Society of Cardiology guidelines. This review provides an overview of the currently available drugs used in AF, with a particular emphasis on their comparative efficacy and safety in different kind of patients. Recent important findings, and advantages and disadvantages of recently approved drugs such as vernakalant and dronedarone, are also discussed.

EXPERT OPINION

AADs remain fundamental in the acute and long-term management of AF, to control symptoms and to reduce the negative impact of the arrhythmia on QoL. The choice of a rate- over rhythm-control strategy should be individualized and based on accurate evaluation of patient medical history and symptoms. New agents will contribute to improve treatment efficacy together with the guarantee of better safety profiles.

Pharmacologic Conversion of Atrial Fibrillation and Atrial Flutter

Atrial fibrillation and atrial flutter are common arrhythmias in everyday clinical settings. Pharmacologic cardioversion (CV) is a simple and widely used strategy for the treatment of these arrhythmias, and many drugs are currently available. The choice of drug is strongly influenced by the time elapsed from atrial fibrillation onset and by a patient's clinical subset. Electrical direct-current CV is the treatment of choice in long-lasting forms; nevertheless, some agents also show efficacy in this setting. In addition, promising results come from studies on the efficacy and safety of new antiarrhythmic drugs and from therapeutic approaches that reduce the need for hospitalization and improve quality of life.

Atrial fibrillation: adverse effects of "pill-in-the-pocket" treatment and propafenone-carvedilol interaction

Propafenone and carvedilol share a common hepatic metabolism involving the oxidative pathway (CYP2D6). Therefore, oral loading with propafenone (as "pill-in-the-pocket" treatment of recent-onset atrial fibrillation) in a patient on concurrent carvedilol treatment may lead to a pharmacokinetic interaction, with high plasma levels of propafenone and potential drug-related adverse effects. In clinical practice, in order to improve the safety of "pill-in-the-pocket" treatment, use of propafenone loading should, in our view, be discouraged in patients on concurrent treatment with carvedilol.

How, why, and when may atrial defibrillation find a specific role in implantable devices? A clinical viewpoint

This viewpoint article discusses the potential for incorporation of atrial defibrillation capabilities in modern multi-chamber devices. In the late 1990s, the possibility of using shock-only therapy to treat selected patients with recurrent atrial fibrillation (AF) was explored in the context of the stand-alone atrial defibrillator. The failure of this strategy can be attributed to the technical limitations of the stand-alone device, low tolerance of atrial shocks, difficulties in patient selection, a lack of predictive knowledge about the evolution of AF, and, last but not least, commercial considerations. An open question is how atrial defibrillation capability may now assume a specific new role in devices implanted for sudden death prevention or cardiac resynchronization. For patients who already have indications for implantable devices, device-based atrial defibrillation appears attractive as a "backup" option for managing AF when preventive pharmacological/electrical measures fail. This and several other personalized hybrid therapeutic approaches await exploration, though assessment of their efficacy is methodologically challenging. Achievement of acceptance by patients is an essential premise for any updated atrial defibrillation strategy. Strategies that are being investigated to improve patient tolerance include waveform shaping, pharmacologic modulation of pain, and patient-activated defibrillation (patients might also perceive the problem of discomfort somewhat differently in the context of a backup therapy). The economic impact of implementing atrial defibrillation features in available devices is progressively decreasing, and financial feasibility need not be a major issue. Future studies should examine clinically relevant outcomes and not be limited (as occurred with stand-alone defibrillators) to technical or other soft endpoints.

Vernakalant (RSD1235): a novel, atrial-selective antifibrillatory agent

This review summarizes the mechanistic properties and the recent experience in the development of a new antiarrhythmic agent, RSD1235 (recently named vernakalant), for the acute conversion of atrial fibrillation to sinus rhythm. Atrial fibrillation is the most common sustained cardiac arrhythmia that is observed in clinical practice and is associated with increased morbidity and mortality, resulting from stroke and exacerbation of heart failure. At present, there is a lack of pharmacologic agents that are able to safely and effectively convert the arrhythmia back to sinus rhythm. Vernakalant has the electrophysiologic properties of a multiple ion channel blocker, developed using a novel approach to target potassium channels that are selectively present in human atria rather than ventricles, and using a rate-dependent blocking strategy for its additional sodium channel block. This paper reviews the mechanism of action of this drug, its performance in preclinical models of efficacy and human disease, and its actions on patients in the completed and published preregistration clinical trials for vernakalant. Overall, vernakalant converted 51.5% of patients who had < 7 days duration of atrial fibrillation and it did this without significantly more cardiovascular adverse events than placebo. Therefore, it must be considered as an important new agent for the treatment of this growing health problem.

Pharmacological cardioversion of atrial fibrillation: current management and treatment options

Atrial fibrillation (AF) is the most common form of arrhythmia, carrying high social costs. It is usually first seen by general practitioners or in emergency departments. Despite the availability of consensus guidelines, considerable variations exist in treatment practice, especially outside specialised cardiological settings. Cardioversion to sinus rhythm aims to: (i) restore the atrial contribution to ventricular filling/output; (ii) regularise ventricular rate; and (iii) interrupt atrial remodelling. Cardioversion always requires careful assessment of potential proarrhythmic and thromboembolic risks, and this translates into the need to personalise treatment decisions. Among the many clinical variables that affect strategy selection, time from onset is crucial. In selected patients, pharmacological cardioversion of recent-onset AF can be a safely used, feasible and effective approach, even in internal medicine and emergency departments. In most cases of recent-onset AF, pharmacological cardioversion provides an important--and probably more cost effective--alternative to electrical cardioversion, which can then be employed as a second-line therapy for nonresponders. Class IC agents (flecainide or propafenone), which can be safely used in hospitalised patients with recent-onset AF without left ventricular dysfunction, can provide rapid conversion to sinus rhythm after either intravenous administration or oral loading. Although intravenous amiodarone requires longer conversion times, it is still the standard treatment for patients with heart failure. Ibutilide also provides good conversion rates and could be used for AF patients with left ventricular dysfunction (were it not for high costs). For long-lasting AF most pharmacological treatments have only limited efficacy and electrical cardioversion remains the gold standard in this setting. However, a widely used strategy involves pretreatment with amiodarone in the weeks before planned electrical cardioversion: this provides optimal prophylaxis and can sometimes even restore sinus rhythm. Dofetilide may also be capable of restoring sinus rhythm in up to 25-30% of patients and can be used in patients with heart failure. The potential risk of proarrhythmia increases the need for careful therapeutic decision making and management of pharmacological cardioversion. The results of recent trials (AFFIRM [Atrial Fibrillation Follow-up Investigation of Rhythm Management] and RACE [Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation]) on rate versus rhythm control strategies in the long term have led to a generalised shift in interest towards rate control. Although carefully designed studies are required to better define the role of pharmacological rhythm control in specific AF settings, this alternative option remains a recommendable strategy for many patients, especially those in acute care.

Atrial Fibrillation: Modern Concepts and Management

Atrial fibrillation (AF) is a common cardiac arrhythmia responsible for significant morbidity and mortality. In recent years, progress has been made in determining the genetic abnormalities that may lead to AF. New trials have shown that rate control and anticoagulation are acceptable as a primary treatment strategy in many patients who have a high risk of recurrence. Newer and safer antiarrhythmics are now available. Pacemaker and implantable cardiac defibrillator technology is rapidly evolving and may play a significant role in future treatment and prevention of AF. Direct thrombin inhibitors are likely to add a user-friendly option to the current standard therapy for stroke prevention.

Antiarrhythmic drug therapy of atrial fibrillation

In the post-AFFIRM era, treatment of AF has become the treatment of symptoms. In some patients, this will be simple rate control, but there remain a significant cohort of patients in whom rate control alone does not give acceptable symptom relief. In this group, antiarrhythmic therapy still has a role, and the AFFIRM trial indicates that this therapeutic strategy is without significant deleterious effect on mortality. The choice of antiarrhythmic agent must be individualized according to underlying cardiac pathologies and comorbidities, however. Most recently, the introduction of dofetilide has widened the therapeutic options in patients with severe heart disease, and the Canadian Trial of Atrial Fibrillation indicated the superior efficacy of amiodarone at low doses. The release/ development of newer Class III antiarrhythmic agents may offer hope for the benefits of amiodarone without the serious adverse effects with long-term therapy.

Advances in the acute pharmacologic management of cardiac arrhythmias

Safe and effective control of rapid ventricular rates in acute-onset atrial fibrillation (AF) can be accomplished with intravenous calcium antagonists, beta-blockers or amiodarone; digoxin is less effective. If pharmacologic cardioversion of AF is desired, single oral doses of propafenone or flecainide are safe and effective in patients without structural heart disease. Intravenous ibulitide is moderately effective in the conversion of persistent AF or atrial flutter, with a small risk of proarrhythmia. In wide QRS complex tachycardia of uncertain origin, adenosine and lidocaine are no longer recommended. Procainamide or amiodarone are the treatment options, but attempts should be made to define the origin of tachycardia. In the treatment of monomorphic ventricular tachycardia, lidocaine is no longer recommended; procainamide or amiodarone are the recommended therapies. In polymorphic ventricular tachycardia with a normal QT interval, beta-blockers are recommended. In shock-refractory ventricular fibrillation, lidocaine, and magnesium are ineffective; intravenous amiodarone should be the treatment of choice.

Class I or class III agents for atrial fibrillation: are asking the right question?

Atrial fibrilliation (AF) is often combined with advanced age and structural heart disease, conditions known to invite serious proarrhythmic complications of antiarrhythmic drug therapy. Recent controlled trials comparing two AF treatment strategies-rhythm control requiring atrial defibrilliation and antiarrhythmic drugs to prevent AF and ventiricular rate control obviating sinus rhythm maintenance with such drugs-showed equal or superior results with rate control. AF is associated with derepressions of "fetospecific" expression patterns that may profoundly alter the responsiveness of atrial muscle to antiarrhythmic drugs. Therefore, effects of drugs predicted according to pharmacological classifications evaluating drug actions in intact myocardium only should be interpreted cautiously. The classification proposed by Vaughan Williams fails to distinguish between acute and chronic drug efficacy and toxicity as recommended in classical pharmacology. There is, however, overwhelming evidence that acute and chronic drug effects often differ fundamentally. For instance, amiodarone acts acutely as a sodium channel blocker, whereas chronic effects may be mediated by a downregulation of thyroid hormone receptors. Meaningful direct effects of amiodarone on atrial potassium channels is questionable, since the main candidate target-current (IKr) may not be expressed in human atrial muscle. Multiple biophysical factors contribute to the lack of ion channel-selective actions of antiarrhythmic agents. Nonselectivity becomes particularly important in the context of mechanisms of action of Vaughan Williams Class I and III agents on human atrial muscle. Preclinical studies indicate that Class I agents such as flecainide and propafenone may act in AF predominantly as Class III agents. Meta-analyses of antiarrhythmic agents for the prevention of AF have failed to reveal superior drugs or drug classes. Superiority of amiodarone over other agents may depend on arbitrary amiodarone-favoring loading protocols producing significant differential effects exclusively during the acute phase of treatment. In conclusion, the classification of current antiarrhythmic agents into Class I and III may not be a useful simplification when applied to the pharmacotherapy of AF.