Atrial flutter with 1:1 atrioventricular conduction caused by propafenone

Safety of Pill-in-the-Pocket Class 1C Antiarrhythmic Drugs for Atrial Fibrillation

BACKGROUND

Guidelines recommend that initial trial of a "pill-in-the-pocket" (PIP) Class 1C antiarrhythmic drug (AAD) for cardioversion of atrial fibrillation (AF) be performed in a monitored setting because of the potential for adverse reactions.

OBJECTIVES

This study sought to characterize real-world, contemporary use of the PIP approach, including the setting of initiation and incidence of adverse events.

METHODS

This retrospective cohort study included all patients at the Hospital of the University of Pennsylvania treated with a PIP approach for AF between 2007 and 2020.

RESULTS

A total of 273 patients (age 56 ± 13 years; 182 [67%] male; CHA₂DS₂VASc score 1.1 ± 1.2) took a first dose of PIP AAD. Flecainide was used in 151 (55%) and propafenone in 122 (45%). The first dose of PIP AAD was taken in a monitored setting in 167 (62%). Significant adverse events occurred in 7 patients (3%), 2 of whom had taken the dose in a monitored setting. Significant adverse events included unexplained syncope (1 of 7), symptomatic bradycardia/hypotension (4 of 7), and 1:1 atrial flutter (2 of 7). All occurred in patients taking 300 mg of flecainide (n = 4) or 600 mg of propafenone (n = 3). Electrical cardioversion was performed in 29 (11%) patients because of failure of the AAD to terminate AF. One patient required intravenous fluids and vasopressors for 2 hours because of persistent hypotension and bradycardia. Two patients required permanent pacemakers for bradycardia. The remaining patients required no intervention.

CONCLUSIONS

Our data support the current recommendation to initiate PIP AAD in a monitored setting because of rare significant adverse reactions that can require urgent intervention.

Old stuff still trending: use of propafenone as a safety net until catheter ablation in a patient with documented pre-excited atrial fibrillation and Wolff-Parkinson-White syndrome - a classic case report

BACKGROUND

Atrial fibrillation in Wolff-Parkinson-White syndrome may result in life-threateningly rapid antegrade conduction over a bypass tract, manifested by an irregular broad-complex (pre-excited) tachycardia that can degenerate to ventricular fibrillation. The shortest pre-excited RR interval below 250 ms during atrial fibrillation (AF) predicts increased risk of sudden cardiac death.

CASE SUMMARY

We report a case of a 43-year-old man with unremarkable cardiac history who presented due to sudden-onset feeling of palpitations and pre-syncope after strenuous lifting. Electrocardiography depicted fast pre-excited AF. The shortest pre-excited RR interval was estimated at 160 ms, indicating an accessory pathway (AP) with short antegrade refractory period at risk for mediating sudden cardiac death. Direct current cardioversion restored sinus rhythm unravelling delta waves. The patient was put on propafenone 450 mg/day having an uneventful clinical course. On Day 10 post-admission, electrophysiological study induced rapid AF but the shortest pre-excited RR interval was substantially increased to 264 ms. A left anterolateral AP was ablated. The patient remained symptom free until his latest follow-up in the 3rd-month post-ablation without manifest pre-excitation on the surface electrocardiogram.

DISCUSSION

Treatment options of pre-excited AF include anti-arrhythmic agents but mainly electrical cardioversion. Cardioversion can safely restore sinus rhythm, while use of anti-arrhythmics often requires intensive care unit monitoring due to the risk of QT prolongation. Catheter ablation is the mainstay of therapy for symptomatic patients. Our rare report highlights the direct impact of propafenone on prolonging the refractoriness of the AP, effectively and safely, and reappraises propafenone's worthiness as a protective measure following pre-excited AF episode until ablation.

Aggravation of atrial arrhythmia by amiodarone during the perinatal period: A case report

RATIONALE

Amiodarone, a broad-spectrum antiarrhythmic drug, is widely used for the clinical treatment of tachyarrhythmias because of its safety and efficacy.

PATIENT CONCERNS

A 30-year-old woman presented with known paroxysmal atrial tachycardia and severe preeclampsia. Two days before admission, she had given birth to twins. She described her symptoms as a sudden palpitation at 10:20 accompanied by chest tightness and shortness of breath.

DIAGNOSIS

Cardiac arrhythmia and acute left heart failure.

INTERVENTIONS

Furosemide and sodium nitroprusside were administered to control the heart failure. At 16:20, 150 mg amiodarone (15 mg/min) was injected intravenously and continued at 1 mg/min. At 16:50, her electrocardiogram showed possible atrial tachycardia or atrial flutter with a ventricular rate of 206 beats/min. Administration of amiodarone was stopped at 17:23, and the medication was changed to esmolol.

OUTCOMES

After 3 minutes, the palpitations stopped, the heart rate changed to a sinus rhythm, and the ventricular rate was 100 beats/min. Four days later, the patient underwent an electrophysiologic study and radiofrequency ablation.

LESSONS

When amiodarone is used to treat atrial arrhythmia, the ventricular rate may accelerate, which can cause patients with borderline heart failure to develop acute heart failure or further deterioration of acute heart failure. For heart failure induced or mediated by atrial arrhythmias, short-term β-blockers may be used to control the ventricular rate more quickly and effectively and to prevent the progression of heart failure.

The efficacy and tolerability of commonly used agents to prevent recurrence of atrial fibrillation after successful cardioversion

A number of therapeutic strategies exist for the restoration and maintenance of sinus rhythm in patients presenting with atrial fibrillation. The acute success rate with electrical cardioversion is high. However, many patients relapse into atrial fibrillation. A major challenge faced by those who care for patients with atrial fibrillation is the long-term maintenance of sinus rhythm whilst avoiding treatment-related adverse effects. This review examines the efficacy and tolerability of conventional anti-arrhythmic drugs for the secondary prevention of atrial fibrillation in the post-cardioversion period.

Wide complex tachycardia in the presence of class I antiarrhythmic agents: a diagnostic challenge

We present two patients with paroxysmal atrial fibrillation on class 1C antiarrhythmic drugs without concomitant atrioventricular (AV) nodal blocking agents who developed atrial flutter with 1:1 AV conduction. Their electrocardiogram revealed wide complex tachycardia with rates >200/minute. Atrial flutter with 1:1 conduction in the presence of class IC antiarrhythmic drugs may present a diagnostic challenge. These cases illustrate the importance of coadministering an AV nodal blocking agent with class IC antiarrhythmic agents in patients with atrial fibrillation. The differential diagnosis of wide complex tachycardia in patients taking class IC agents should include atrial flutter with 1:1 AV conduction.

Accuracy of diagnosing atrial flutter and atrial fibrillation from a surface electrocardiogram by hospital physicians: analysis of data from internal medicine departments

INTRODUCTION

Atrial fibrillation (AF) and atrial flutter (AFL) are clinically and electrocardiographically similar. However, considering significant therapeutic differences, differentiation of these 2 arrhythmias is essential. Our aims were to evaluate the misdiagnosis rate among electrocardiograms (ECGs) interpreted as AF or AFL by internists and to describe the factors that could be responsible for the misinterpretation.

METHODS

We evaluated patients discharged with a diagnosis of AF or AFL from internal medicine wards of a tertiary referral center. The reanalysis of the ECGs was performed by 2 senior cardiologists (1 electrophysiologist), blinded to the primary analysis and patient's clinical data.

RESULTS

The ECGs of 44 of 268 (16%) patients were misinterpreted and consisted of: 25 (57%) AFL, 5 (11%) SVT, 7 (16%) sinus rhythm with premature atrial beats and 7 (16%) AF. The baseline diagnosis was correct in 212 of 246 (86%) for AF and 12 of 22 (55%) for AFL, P < 0.001. A significantly higher rate of AFL was misdiagnosed compared with AF [25 of 37 (68%) versus 7 of 219 (3%), respectively; P < 0.001], higher in atypical than typical AFL [16 of 20 (80%) versus 9 of 17 (53%), respectively; P = 0.07]. Reduced quality ECGs was found more often among the incorrectly than the correctly diagnosed ECGs (P < 0.001].

CONCLUSIONS

ECGs, interpreted as AF or AFL by internists, are often misdiagnosed. AFL was misdiagnosed more often than AF, with atypical more often than typical AFL. Consulting with a cardiologist and applying diagnostic criteria may reduce misdiagnosis.

[Rate versus rhythm control with and without heart failure]

Atrial fibrillation and congestive heart failure are frequently associated with complex interactions. Patients with both diseases bear a sophisticated therapeutic challenge for the attending physician. The approach to treat atrial fibrillation differs for patients with and without heart failure in several aspects. Basic requirements are the treatment of the underlying diseases and prophylaxis of thromboembolic complications. Rate and rhythm control are the two main therapeutic strategies for atrial fibrillation according to the current guidelines. Large trials including the recently published AF-CHF study (Atrial Fibrillation - Congestive Heart Failure) failed to demonstrate a difference in mortality for both strategies. Thus, the therapeutic decision is mainly based on the patient's symptoms to improve quality of life. Rate control should be applied to asymptomatic patients or if rhythm control has already failed. If beta-blockers and digoxin have failed to control heart rate, His ablation with pacemaker implantation can be considered. In patients without heart disease, class I antiarrhythmic drugs and, in case of ineffectiveness, amiodarone or catheter ablation are recommended for rhythm control. First data concerning catheter ablation of atrial fibrillation in heart failure are promising and randomized studies are on the way. Rhythm control remains first-line therapy in recent-onset or highly symptomatic paroxysmal or persistent atrial fibrillation patients with and without heart failure.

Long-term efficacy of hybrid pharmacologic and ablation therapy in patients with pilsicainide-induced atrial flutter

BACKGROUND

Combination therapy with catheter ablation of the cavo-tricuspid isthmus and continued drug therapy, that is, "hybrid therapy," in patients with atrial fibrillation (AF) and drug-induced atrial flutter (AFL) is reported to be an alternative means of achieving and maintaining sinus rhythm. With respect to choosing this method among the rhythm control therapies, its long-term efficacy and the prevalence of AFL in patients with AF are very important and have not been fully elucidated.

HYPOTHESIS

The purpose of this study was to investigate the long-term effectiveness of this hybrid therapy and the dose prevalence in Ic drug-induced AFL.

METHODS

The subjects were 89 patients (aged 62.4 years, 72 men) with episodes of AF (paroxysmal type: 65, persistent type: 11, permanent type: 13). After 4 weeks of oral pilsicainide administration, the dose was increased in those with no documented AFL. The patients who experienced AFL with pilsicainide (Ic-AFL) underwent ablation.

RESULTS

Pilsicainide administration resulted in the common type AFL in 17 patients (19.1%). The pilsicainide plasma concentration in the patients with Ic-AFL was significantly higher than in those without AFL (0.79 +/- 0.41 vs. 0.51 +/- 0.24 microg/ml, respectively, p < 0.01). During a 10-54 (mean 37 +/- 14) month follow-up period, sinus rhythm was maintained in 10 of 12 patients after successful ablation followed by continued antiarrhythmic drug administration.

CONCLUSIONS

Hybrid therapy with ablation and high doses of pilsicainide was useful in maintaining sinus rhythm in some selected patients with AF and drug-induced AFL.

Drug-induced atrial fibrillation

Atrial fibrillation (AF) is the most common sustained rhythm disorder observed in clinical practice and predominantly associated with cardiovascular disorders such as coronary heart disease and hypertension. However, several classes of drugs may induce AF in patients without apparent heart disease or may precipitate the onset of AF in patients with preexisting heart disease. We reviewed the literature on drug-induced AF, using the PubMed/Medline and Micromedex databases and lateral references. Successively, we discuss the potential role in the onset of AF of cardiovascular drugs, respiratory system drugs, cytostatics, central nervous system drugs, genitourinary system drugs, and some miscellaneous agents. Drug-induced AF may play a role in only a minority of the patients presenting with AF. Nevertheless, it is important to recognize drugs or other agents as a potential cause, especially in the elderly, because increasing age is associated with multiple drug use and a high incidence of AF. This may contribute to timely diagnosis and management of drug-induced AF.

Syncope in patients with atrial flutter during treatment with class Ic antiarrhythmic drugs

We describe 2 atrial flutter (AFL) patients with syncope during treatment with class Ic antiarrhythmic drugs. During the syncope, 1:1 atrioventricular (AV) conduction during AFL preceded a wide QRS tachycardia. The class Ic drugs, flecainide and pilsicainide, slowed the atrial rate, resulting in AFL with 1:1 AV conduction, and the width of the QRS complexes became wider during the tachycardia. Syncope was abolished after successful radiofrequency catheter ablation of the AFL. These potential proarrhythmic effects of the class Ic drugs should be taken into account in AFL patients, and concomitant use of beta-blocking agents would be critical to prevent proarrhythmias.

Antiarrhythmic drug initiation in patients with atrial fibrillation

Antiarrhythmic drugs remain the mainstay of treatment of atrial fibrillation, but their potential proarrhythmic effects hamper their optimal use. Drug-induced tachyarrhythmias (ventricular tachycardia or atrial tachyarrhythmias with rapid ventricular response) are life-threatening and often cause syncope. Because these events tend to cluster shortly after drug initiation, it is common practice to routinely hospitalize patients for drug initiation under continuous electrocardiographic surveillance. The low incidence of serious proarrhythmia makes the cost-effectiveness of this practice controversial. Torsades de pointes, in particular, can be predicted by the presence of one or more of the following risk factors: female gender, structural heart disease, prolonged baseline QT interval, bradycardia, hypokalemia, previous proarrhythmic responses, and higher drug plasma levels. Proarrhythmia induced by class IC agents is seen almost exclusively in patients with structural heart disease and ventricular dysfunction. A variety of monitoring devices permit electrocardiographic monitoring of patients in the outpatient setting. Efficient clinical pathways for the safe initiation of antiarrhythmic drugs in patients with atrial fibrillation do not require universal hospital admission. In patients without structural heart disease, outpatient initiation of most antiarrhythmic drugs appears safe. In patients with significant structural heart disease, class IC drugs are contraindicated, and most other drugs should be initiated in the hospital under continuous monitoring. The incidence of severe proarrhythmia is very low when loading doses of amiodarone of 600 mg/d or less are given to outpatients with structural heart disease.