Is hospital admission for initiation of antiarrhythmic therapy with sotalol for atrial arrhythmias required? Yield of in-hospital monitoring and prediction of risk for significant arrhythmia complications

Safety of outpatient commencement of sotalol

Background

Inpatient monitoring is recommended for sotalol initiation.

Objective

The purpose of this study was to assess the safety of outpatient sotalol commencement.

Methods

This is a multicenter, retrospective, observational study of patients initiated on sotalol in an outpatient setting. Serial electrocardiogram monitoring at day 3, day 7, 1 month, and subsequently as clinically indicated was performed. Corrected QT (QTc) interval and clinical events were evaluated.

Results

Between 2008 and 2023, 880 consecutive patients who were commenced on sotalol were evaluated. Indications were atrial fibrillation/flutter in 87.3% (n = 768), ventricular arrhythmias in 9.9% (n = 87), and other arrhythmias in 2.8% (n = 25). The daily dosage at initiation was 131.0 ± 53.2 mg/d. The QTc interval increased from baseline (431 ± 32 ms) to 444 ± 37 ms (day 3) and 440 ± 33 ms (day 7) after sotalol initiation (P < .001). Within the first week, QTc prolongation led to the discontinuation of sotalol in 4 and dose reduction in 1. No ventricular arrhythmia, syncope, or death was observed during the first week. Dose reduction due to asymptomatic bradycardia occurred in 3 and discontinuation due to dyspnea in 3 within the first week. Overall, 1.1% developed QTc prolongation (>500 ms/>25% from baseline); 4 within 3 days, 1 within 1 week, 4 within 60 days, and 1 after >3 years. Discontinuation of sotalol due to other adverse effects occurred in 41 patients within the first month of therapy.

Conclusion

Sotalol initiation in an outpatient setting with protocolized follow-up is safe, with no recorded sotalol-related mortality, ventricular arrhythmias, or syncope. There was a low incidence of significant QTc prolongation necessitating discontinuation within the first month of treatment. Importantly, we observed a small incidence of late QT prolongation, highlighting the need for vigilant outpatient surveillance of individuals on sotalol.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Association of sotalol versus atenolol therapy with survival in dogs with severe subaortic stenosis

INTRODUCTION/OBJECTIVES

Dogs with severe subaortic stenosis (SAS) are at risk of dying suddenly from fatal arrhythmias. Survival is not improved when treated with pure beta-adrenergic receptor (β)-blockers; however, the effect of other antiarrhythmic drugs on survival is unknown. Sotalol is both a β-blocker and a class III antiarrhythmic drug; the combination of these differing mechanisms may provide benefit to dogs with severe SAS. The primary objective of this study was to compare survival in dogs with severe SAS that were treated with either sotalol or atenolol. The secondary objective was to evaluate the effect of pressure gradient (PG), age, breed, and aortic regurgitation on survival.

ANIMALS

Forty-three client-owned dogs.

MATERIALS AND METHODS

Retrospective cohort study. Medical records of dogs diagnosed with severe SAS (PG ≥ 80 mmHg) between 2003 and 2020 were reviewed.

RESULTS

No statistical difference was identified in survival time between dogs treated with sotalol (n = 14) and those treated with atenolol (n = 29) when evaluating all-cause mortality (p=0.172) or cardiac-related mortality (p=0.157). Of the dogs that died suddenly, survival time was significantly shorter in dogs treated with sotalol compared to those treated with atenolol (p=0.046). Multivariable analysis showed that PG (p=0.002) and treatment with sotalol (p=0.050) negatively influenced survival in the dogs that died suddenly.

CONCLUSIONS

Sotalol did not have a significant effect on survival overall but may increase the risk of sudden death in dogs with severe SAS compared to atenolol.

Economics and Outcomes of Sotalol In-Patient Dosing Approaches in Patients with Atrial Fibrillation

Introduction

There exists variability in the administration of in‐patient sotalol therapy for symptomatic atrial fibrillation (AF). The impact of this variability on patient in‐hospital and 30‐day posthospitalization costs and outcomes is not known. Also, the cost impact of intravenous sotalol, which can accelerate drug loading to therapeutic levels, is unknown.

Methods

One hundred and thirty‐three AF patients admitted for oral sotalol initiation at an Intermountain Healthcare Hospital from January 2017 to December 2018 were included. Patient and dosing characteristics were described descriptively and the impact of dosing schedule was correlated with daily hospital costs/clinical outcomes during the index hospitalization and for 30 days. The Centers for Medicare and Medicaid Services reimbursement for 3‐day sotalol initiation is $9263.51. Projections of cost savings were made considering a 1‐day load using intravenous sotalol that costs $2500.00 to administer.

Results

The average age was 70.3 ± 12.3 years and 60.2% were male with comorbidities of hypertension (83%), diabetes (36%), and coronary artery disease (53%). The mean ejection fraction was 59.9 ± 7.8% and the median corrected QT interval was 453.7 ± 37.6 ms before sotalol dosing. No ventricular arrhythmias developed, but bradycardia (<60 bpm) was observed in 37.6% of patients. The average length of stay was 3.9 ± 4.6 (median: 2.2) days. Postdischarge outcomes and rehospitalization rates stratified by length of stay were similar. The cost per day was estimated at $2931.55 (1. $2931.55, 2. $5863.10, 3. $8794.65, 4. $11 726.20).

Conclusions

In‐patient oral sotalol dosing is markedly variable and results in the potential of both cost gain and loss to a hospital. In consideration of estimated costs, there is the potential for $871.55 cost savings compared to a 2‐day oral load and $3803.10 compared to a 3‐day oral load.

Outpatient Initiation of Sotalol in Patients with Atrial Fibrillation: Utility of Cardiac Implantable Electronic Devices for Therapy Monitoring

Background

Antiarrhythmic drugs are often used in the management of patients with atrial fibrillation (AF). Sotalol is conventionally initiated in the inpatient setting for monitoring efficacy and adverse effects, including QTc interval prolongation and torsades de pointes (TdP) proarrhythmia.

Objective

We aimed to evaluate the efficacy and safety of outpatient initiation of sotalol for the treatment of AF in a select group of patients with cardiac implantable electronic devices (CIEDs): permanent pacemakers (PPMs), implantable cardioverter defibrillators (ICDs), and implantable loop recorders (ILRs) capable of continuous rhythm monitoring remotely.

Methods

We conducted our clinical study in a real-world practice setting with longitudinal follow-up of the study cohort. We included adult patients with symptomatic paroxysmal and persistent AF eligible for sotalol for rhythm control strategy and who had CIEDs in our study. Patients with a known contraindication to sotalol were excluded. After making a shared management decision with patients, sotalol was initiated as an outpatient, with regular clinical encounters with patients to assess the efficacy and safety of treatment, and monitoring cardiac rhythm and QTc intervals with CIEDs utilizing their remote monitoring platforms.

Results

The study cohort comprised 105 patients; 38 (36%) females, mean age ± standard deviation (SD) 73.9 ± 10.36 years, and with a CHA₂DS₂-VASc score of 3.26 ± 1.37 and left ventricular ejection fraction of 60.16 ± 9.10%. Twenty-six (24.8%) patients were implanted with PPMs, 10 (9.5%) with dual-chamber ICDs, and 69 (65.7%) with ILRs. Over a follow-up period of 23 ± 15 months, sotalol was continued at a steady median dose of 80 mg twice daily, 105 ± 42 mg (mean ± SD) in 77 (73%) patients who maintained sinus rhythm, and discontinued in 28 (27%) patients because of inefficacy or development of adverse effects. No adverse effects relating to QTc prolongation and TdP or mortality were observed during the study period.

Conclusions

Effective and safe outpatient initiation and maintenance of sotalol therapy is possible in select patients who have CIEDs for continuous remote monitoring and surveillance capabilities.

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

"Preventive" pacing in patients with tachy-brady syndrome (TBS): Confirming a common practice

AIMS

Many tachy-brady syndrome (TBS) patients, are implanted a permanent pacemaker (PPM) to allow continuation of anti-arrhythmic drug (AAD) therapy to maintain sinus rhythm. Many of these PPM's are implanted as a preventive measure, in absence of symptomatic bradycardia. Our primary aim was to evaluate pacing use among these patients and find predictors for PPM use. Our secondary aim was to appreciate the portion of these patients who progress to permanent atrial fibrillation (AF).

METHODS

Retrospective study of TBS patients implanted a PPM as preventive measure, dividing cases into defined categories regarding highest percent atrial and ventricular pacing documented in PPM clinic visits during 3 year follow-up (F/U) period. Patients' baseline characteristics and AAD therapy were compared between cases with a major (>90%) pacing use and cases with <90% pacing use to find predictors for pacing use. Multivariable logistic regression was applied to identify independent variables associated with major pacing use.

RESULTS

Our study included 119 TBS patients. Most (86.5%) TBS patients had a moderate (>50%) pacing use and 58% had a major pacing use. Significant association was found between pre-implant severe sinus bradycardia (<40 bpm), first degree atrioventricular block and amiodarone treatment to major pacing use on univariate analysis and severe sinus bradycardia was significantly associated with major pacing on multivariate analysis as well. Only minority (16.8%) of TBS patients progressed to permanent AF during the study F/U period.

CONCLUSION

Our study reveals most TBS patients succeed to maintain sinus rhythm using an AAD with a significant pacing use, suggesting preventive PPM implantation might be advantageous in these cases. Pre-implant severe sinus bradycardia (<40 bpm) is a possible predictor for major pacing use in this population.

Resolution of Fetal Hydrops Dependent on Sustained Fetal Supraventricular Tachycardia after Digoxin Therapy

We present a special case of fetal supraventricular tachycardia detected at 34 weeks gestation. Fetal hydrops was noted on ultrasound upon admission. Normal fetal heart rate was maintained for three weeks by maternal administration of digoxin. A live infant was delivered via caesarian section at 37 weeks gestation. This clinical case demonstrated that pharmacological treatment can be effective and helps to prolong pregnancy safely.

Evaluation and Management of Premature Ventricular Complexes

Premature ventricular complexes (PVCs) are extremely common, found in the majority of individuals undergoing long-term ambulatory monitoring. Increasing age, a taller height, a higher blood pressure, a history of heart disease, performance of less physical activity, and smoking each predict a greater PVC frequency. Although the fundamental causes of PVCs remain largely unknown, potential mechanisms for any given PVC include triggered activity, automaticity, and reentry. PVCs are commonly asymptomatic but can also result in palpitations, dyspnea, presyncope, and fatigue. The history, physical examination, and 12-lead ECG are each critical to the diagnosis and evaluation of a PVC. An echocardiogram is indicated in the presence of symptoms or particularly frequent PVCs, and cardiac magnetic resonance imaging is helpful when the evaluation suggests the presence of associated structural heart disease. Ambulatory monitoring is required to assess PVC frequency. The prognosis of those with PVCs is variable, with ongoing uncertainty regarding the most informative predictors of adverse outcomes. An increased PVC frequency may be a risk factor for heart failure and death, and the resolution of systolic dysfunction after successful catheter ablation of PVCs demonstrates that a causal relationship can be present. Patients with no or mild symptoms, a low PVC burden, and normal ventricular function may be best served with simple reassurance. Either medical treatment or catheter ablation are considered first-line therapies in most patients with PVCs associated with symptoms or a reduced left ventricular ejection fraction, and patient preference plays a role in determining which to try first. If medical treatment is selected, either β-blockers or nondihydropyridine calcium channel blockers are reasonable drugs in patients with normal ventricular systolic function. Other antiarrhythmic drugs should be considered if those initial drugs fail and ablation has been declined, has been unsuccessful, or has been deemed inappropriate. Catheter ablation is the most efficacious approach to eradicate PVCs but may confer increased upfront risks. Original research remains necessary to identify individuals at risk for PVC-induced cardiomyopathy and to identify preventative and therapeutic approaches targeting the root causes of PVCs to maximize effectiveness while minimizing risk.

Multicenter Analysis of Dosing Protocols for Sotalol Initiation

Sotalol, a Vaughan-Williams Class III antiarrhythmic medication, is used to manage atrial arrhythmias. Due to its QT-prolonging effect and subsequent increased risk of torsade de pointes, many centers admit patients during the initial dosing period. Despite its widespread use, little information is available regarding dosing protocols during this period. In this multicenter investigation, dosing protocols in patients initiating sotalol therapy were examined to identify predictors of successful sotalol initiation. Over a 4-year period, patients admitted to 5 hospitals in the United States for inpatient telemetry monitoring during initiation for nonresearch purposes were enrolled. A 3-day course of 5 of 6 doses of sotalol was considered successful completion of the loading protocol. Of the 213 enrolled patients, over 90% were successfully discharged on sotalol. Significant bradycardia, ineffectiveness, and excessive QT prolongation were reasons for failed completion. Absence of a dose adjustment was a strong predictor of successful initiation (odds ratio: 6.6, 95% confidence interval: 1.3-32.7, P = .02). Hypertension, use of a calcium channel blocker, use of a separate β-blocker, and presence of a pacemaker were predictors of dose adjustments. Marginal structural models (ie, inverse probability weighting based on probability of a dose adjustment) verified that these factors also predicted successful initiation via preventing any dose adjustment and suggests that considering these factors may result in a higher likelihood of successful initiation in future investigations. In conclusion, we found that the majority of patients admitted for sotalol initiation are successfully discharged on the medication. The study findings suggest that factors predicting need for dose adjustment can be used to identify patients who could undergo outpatient initiation. Prospective studies are needed to verify this approach.

Determinants of cardiac repolarization and risk for ventricular arrhythmias during mild therapeutic hypothermia

PURPOSE

We aimed to investigate the factors that modulate the extent of QTc prolongation and potential arrhythmogenic consequences during mild therapeutic hypothermia (MTH).

METHODS

We studied 205 patients after out-of-hospital cardiac arrest (131 underwent MTH). QTc was measured at baseline, 3h, 6h, 12h, 24h (end of hypothermia), 48h and 72h, and ventricular arrhythmias quantified.

RESULTS

During MTH, the QTc interval increased progressively peaking at 12h (mean increase 42ms, 95% CI 30-55). There was a strong gender effect (P<0.001) and a significant gender-by-MTH interaction (P=0.004). At 12h, the QTc interval was markedly longer in women as compared with men (mean difference 50ms [95% CI 27-73]. Anoxic brain injury (P=0.002) was also positively associated with QTc prolongation. The risk for ventricular arrhythmic events was not higher with MTH compared with no hypothermia (incidence rate ratio 0.57, 95% CI 0.32-1.02, P=0.06). However, typical cases of Torsade de pointes occurred in association with AV block and LQT2.

CONCLUSION

QTc prolongation during MTH is strongly affected by female gender and moderately by concomitant anoxic brain injury. Although the overall risk for ventricular arrhythmias is not greater with MTH, Torsade de pointes may develop when other contributing factors coexist.

Safety of Twice Daily Sotalol in Patients with Renal Impairment: A Single Center, Retrospective Review

Background

The class III antiarrhythmic sotalol is renally eliminated with a dose-related propensity to cause adverse drug reactions (ADR) potentially leading to life-threatening arrhythmias. Although product labeling recommends once daily dosing in patients with renal impairment, twice daily dosing is commonly utilized. This study evaluates the safety of this practice.

Methods

This retrospective, observational study examined renally impaired patients with atrial fibrillation or atrial flutter admitted for sotalol initiation from July 1, 2012 - December 31, 2014, then for up to 20 months after initiation. Primary endpoints included rates of ADR and therapy changes due to ADR. Secondary endpoints included therapy changes due to arrhythmia recurrence, admissions due to arrhythmia recurrence, and therapy changes for any cause.

Results

Analysis included 134 patients with an average creatinine clearance of 51 ml/min, followed over a median of 170 days. Length of stay averaged 3 days withADR occurring in 53.7% of patients, most commonly QT prolongation or bradycardia. Therapy change due to ADR occurred in 45.5% of patients (n=61). Therapy change due to arrhythmia recurrence occurred in 23.1% (n=31), admission due to arrhythmia recurrence occurred in 24.6% (n=33), and therapy change for any cause occurred in 74.6% (n=100).

Conclusion

Initiating sotalol twice daily in renally impaired patients results in ADR and therapy change rates consistent with rates seen in clinical practice for non-renally impaired patients, with minimal length of stay.This practice may be reasonable when initiated in the acute care setting with subsequent outpatient monitoring, however further study is needed.

Perioperative management of patients with atrial fibrillation receiving anticoagulant therapy

The number of patients with atrial fibrillation (AF) and the number of patients indicated for anticoagulant therapy have been increasing because AF would affect patient survival due to thromboembolism. Once AF develops, following the disappearance of pulsation, the circumstances within the atrium become prothrombotic and thrombus formation within the left atrium occurs in patients with AF. In recent years, not only warfarin but also new oral anticoagulants were introduced clinically and have become used as oral anticoagulants. In the perioperative period, the risk of major hemorrhage needs to be reduced. On the other hand, the suspension of anticoagulant therapy and neutralization of anticoagulant effects elevate the risk of thrombosis. The perioperative management of patients receiving anticoagulant therapy is different from that of scheduled surgery and emergency surgery. In addition, knowledge of the characteristics of each oral anticoagulant is required at drug cessation and resumption. Unlike warfarin, which has been used in the past five decades, direct oral anticoagulants (DOACs) do not have sensitive indicators such as prothrombin time-international normalized ratio. To avoid major hemorrhages and thromboembolism, quantitative assays can be implemented for DOAC monitoring and for reversal therapies in perioperative settings.

Does Sotalol Still Have a Role in the Management of Arrhythmias?

Despite proven effectiveness in treating tachyarrhythmias, sotalol is proarrhythmic and can cause torsades de pointes. Given the emergence of studies that show no benefit from rhythm control strategies in managing atrial fibrillation, as well as the introduction of nonpharmacological approaches to treating arrhythmias, we felt it necessary to ascertain if there was any role for sotalol given its side effects. Review of the literature regarding sotalol use in the prevention and treatment of supraventricular and ventricular tachyarrhythmias seems to show that more effective and safer agents and nonpharmacological alternatives are currently available. However, sotalol still seems to be useful in preventing supraventricular tachyarrhythmias postcardiac surgery and in reverting hemodynamically stable sustained ventricular tachycardias in the setting of coronary artery disease. Its role in the prevention of tachyarrhythmias in the setting of arrhythmogenic right ventricular cardiomyopathy requires further investigation.

Safety of Outpatient Initiation of Disopyramide for Obstructive Hypertrophic Cardiomyopathy Patients

Background

Disopyramide is effective in ameliorating symptoms in patients with hypertrophic cardiomyopathy; however, its potential for proarrhythmic effect has raised concerns about its use in the ambulatory setting. The risk of initiating disopyramide in this manner has never been evaluated.

Methods and Results

All charts of patients seen in the outpatient hypertrophic cardiomyopathy clinic between 2010 and 2014 were screened for initiation of disopyramide and data were extracted. Disopyramide in our clinic is usually initiated at a dose of 300 mg daily and titrated during follow‐up. A total of 2015 patients were seen in the clinic, including 168 who were started on disopyramide. There were no cardiac events within 3 months of disopyramide initiation. During long‐term follow‐up (255 patient‐years; mean, 447 days; interquartile range, 201–779), only 2 patients developed cardiac events (syncope of unknown cause in both). Thirty‐eight patients (23%) developed side effects of disopyramide and 18 (11%) stopped the drug because of these side effects. Of the patients continuing disopyramide long term, 63% remained free of septal reduction interventions at end of follow‐up. Disopyramide at a dose of 300 mg prolonged the mean QTc interval by 19±23 ms; however, increasing the dose to 600 mg had no further significant effect.

Conclusions

Initiation of disopyramide in the outpatient setting is safe and the risk of subsequent sudden cardiac death is low. Because of its QT‐prolonging effect, precautions may be necessary in patients at higher risk of torsades de pointes.

Sotalol

Sotalol is effective for treating atrial fibrillation (AF), ventricular tachycardia, premature ventricular contractions, and supraventricular tachycardia. Racemic (DL) sotalol inhibits the rapid component of the delayed rectifier potassium current. There is a near linear relationship between sotalol dosage and QT interval prolongation. However, in dose ranging trials in patients with AF, low-dose sotalol was not more effective than placebo. Orally administered sotalol has a bioavailability of nearly 100%. The only significant drug interactions are the need to avoid or limit use of concomitant drugs that cause QT prolongation, bradycardia, and/or hypotension.

Severe iatrogenic bradycardia related to the combined use of beta-blocking agents and sodium channel blockers

Purpose

Drug-induced bradycardia is common during antiarrhythmic therapy; the major culprits are beta-blockers. However, whether other antiarrhythmic drugs are also a significant cause of this, alone or in combination with beta-blockers, is not well known.

Methods

We retrospectively investigated the records of all patients hospitalized at our institution for drug-related bradycardia from the years 2004 to 2012. Patients with cardiac disease and electrolytic or hormonal abnormalities that could cause bradyarrhythmias were excluded.

Results

Eight patients were identified (mean age, 79±5 years; range, 71–85 years; 6 women). Three patients were taking only beta-blockers (hereafter referred to as the BB group), while five patients were on both beta-blockers and Na channel blockers (hereafter referred to as the BB + Na group). Heart rates ranged from 20∼49 beats/minute on arrival. The initial electrocardiogram showed sinus bradycardia (n=6) or sinus arrest with escape beats (n=2). QRS duration was 80–100 ms. The clinical presentation of the BB + Na group was considerably worse than that of the BB group, and included cardiogenic shock and heart failure. Four of the BB + Na patients had been on their medications for over 300 days. The BB group recovered solely with drug discontinuation, while 4 of the 5 patients in the BB + Na group needed additional treatments, such as intravenous administration of atropine or adrenergic agonist and temporary pacing. Bradycardia did not recur during follow-up (median, 687 days).

Conclusion

Although wide QRS ventricular tachyarrhythmia is a better known proarrhythmic effect of Na channel blockers, life-threatening bradycardia may also occur in combination with beta-blockers in the elderly, even months after the start of medication, and at plasma concentrations that do not prolong QRS width.

Risk prediction for adverse events during initiation of sotalol and dofetilide for the treatment of atrial fibrillation

BACKGROUND

Inpatient antiarrhythmic drug initiation for atrial fibrillation is mandated for dofetilide (DF) and is often performed for sotalol (SL), particularly if proarrhythmia risk factors are present. Whether low-risk patients can be identified to safely allow outpatient initiation is unknown.

METHODS

A single-center retrospective cohort study was performed on patients initiated with DF or SL. Risk factors for adverse events (AEs), defined as any arrhythmia or electrocardiogram change requiring dose reduction or cessation, were identified.

RESULTS

Of 329 patients, 227 (69%) received SL and 102 (31%) DF. The cohort had a mean age of 63 ± 13 years; 70% of patients were male and had a baseline QTc of 440 ± 37 ms. A total of 105 AEs occurred in 92 patients: QTc prolongation or ventricular tachyarrhythmia in 70 patients (67% of AEs), bradyarrhythmias in 35 patients (33% of AEs), with some experiencing both AE types. Ventricular arrhythmias were seen in 23 patients (7%) and torsades de pointes in one (0.3%). Total AE rates were similar between drugs (P = 0.09); however, DF patients had more QTc prolongation or ventricular arrhythmias (P = 0.001). In SL patients, there were no predictors for QTc prolongation or ventricular proarrhythmia. In DF patients, higher baseline QTc interval (odds ratio = 1.64/25 ms, P = 0.01) was an independent predictor of QTc prolongation or ventricular proarrhythmias. For patients without proarrhythmia risk factors, overall AE rate was 26%.

CONCLUSIONS

In conclusion, AEs are common during DF and SL initiation but rarely severe in hospitalized inpatients. Baseline QTc predicts AEs for DF patients only and AE are common even in "low-risk" patients. These results support in-hospital drug initiation for all DF and SL patients.

QT variability during initial exposure to sotalol: experience based on a large electronic medical record

AIMS

A prolonged QT interval is associated with increased risk of Torsades de pointes (TdP) and may be fatal. We sought to investigate the extent to which clinical covariates affect the change in QT interval among 'real-world' patients treated with sotalol and followed in an electronic medical record (EMR) system.

METHODS AND RESULTS

We used clinical alerts in our EMR system to identify all patients in whom a new prescription for sotalol was written (2001-11). Rate-corrected QT (QTc) was calculated by Bazett's formula. Correlates of sotalol-induced change in the QTc interval and sotalol discontinuation were examined using linear and logistic regression, respectively. Overall, 541 sotalol-exposed patients were identified (n = 200 women, 37%). The mean first sotalol dose was 86 ± 39 mg, age 64 ± 13 years, and BMI 30 ± 7 kg/m(2). Atrial fibrillation/flutter was the predominant indication (92.2%). After initial exposure, the change in the QTc interval from baseline was highly variable: ΔQTc after 2 h = 3 ± 42 ms (P = 0.17) and 11 ± 37 ms after ≥48 h (P < 0.001). Multivariable linear regression analysis identified female gender and age, reduced left ventricular ejection fraction, high sotalol dose, hypertrophic cardiomyopathy, and loop diuretic co-administration as correlates of increased ΔQTc at ≥48 h (P < 0.05 for all). Within 3 days of initiation, 12% discontinued sotalol of which 31% were because of exaggerated QTc prolongation. One percent developed TdP.

CONCLUSION

In this EMR-based cohort, the increase in QTc with sotalol initiation was highly variable, and multiple clinical factors contributed. These data represent an important step in ongoing work to identify real-world patients likely to tolerate long-term therapy and reinforces the utility of EMR-based cohorts as research tools.

Increased risk of antipsychotic-related QT prolongation during nighttime: a 24-hour holter electrocardiogram recording study

Most antipsychotic agents can cause QT prolongation, which causes torsades de pointes. The QT interval in healthy subjects is longer during nighttime than during daytime. The QT interval of patients treated with antipsychotics may be prolonged during nighttime, and the effects of antipsychotics on the QT interval may differ between antipsychotics. This study investigated the circadian dynamics of the QT interval in patients treated with antipsychotics and healthy controls, using a 24-hour Holter electrocardiogram in a clinical setting. Sixty-six patients with a diagnosis of schizophrenia that were treated with risperidone or olanzapine and 40 healthy volunteers were enrolled. The QT intervals were corrected using the Fridericia formula (QTcF = QT / RR). Mean ± SD nighttime QTcFs were 411.6 ± 29.0, 395.9 ± 21.2, and 387.8 ± 19.0 milliseconds (ms) in the risperidone, olanzapine, and control groups, respectively. The mean daytime QTcFs were 397.7 ± 23.4, 392.4 ± 18.9, and 382.6 ± 17.3 ms, respectively. The mean nighttime QTcF of the risperidone group was significantly longer than that of the olanzapine and control groups, although there was no significant difference in the mean daytime QTcF between the risperidone and olanzapine groups. The current study used 24-hour Holter electrocardiograms to reveal significantly longer QT intervals in the risperidone group especially during nighttime. In clinical practices, evaluations of the QT interval have been conducted over short periods in the daytime, but it is believed that such methods may not be able to fully elucidate the effects of antipsychotics on the QT interval.

QTc prolongation assessment in anticancer drug development: clinical and methodological issues

Cardiac safety assessments are commonly employed in the clinical development of investigational oncology medications. In anti-cancer drug development there has been increasing consideration for the potential of a compound to cause adverse electrocardiographic changes, especially QT interval prolongation, which can be associated with risk of torsades de pointes and sudden death. Irrespective of overt clinical toxicities, QTc assessment can potentially influence decision making at many levels during the conduct of clinical studies, including eligibility for protocol therapy, dose delivery or discontinuation, and analyses of optimal dose for subsequent development. Given the potential for serious and irreversible morbidity from cardiac adverse events, it is understandable that cardiac safety results can have broad impact on study conduct and patient management. The methodologies for risk management of QTc prolongation for non cardiac drugs have been developed out of experiences primarily from drugs used to treat non life-threatening illnesses in a chronic setting such as antibiotics or antihistamines. Extrapolating these approaches to drugs for treating cancer over an acute period may not be appropriate. Few specific guidelines are available for risk management of cardiac safety in the development and use of oncology drugs. In this manuscript, clinical and methodological issues related to QTc prolongation assessment will be reviewed. Discussions about limitations in phase-I design and oncology drug development will be highlighted. Efforts are needed to refine strategies for risk management, avoiding unintended consequences that negatively affect patient access and clinical development of promising new cancer treatments. A thoughtful risk management plan generated by an organized collaboration between oncologists, cardiologists, and regulatory agencies to support a development programme essential for oncology agents with cardiac safety concerns.

Current concepts in the mechanisms and management of drug-induced QT prolongation and torsade de pointes

Drug-induced long QT syndrome is characterized by a prolonged corrected QT interval (QTc) and increased risk of a polymorphic ventricular tachycardia known as torsade de pointes (TdP). We review mechanisms, predispositions, culprit agents, and management of this potentially fatal phenomenon. Virtually all drugs that prolong QTc block the rapid component of the delayed rectifier current (I(kr)). Some drugs prolong QTc in a dose-dependent manner, others do so at any dose. Most patients that develop drug-induced TdP have underlying risk factors. Female sex is the most common. Implicated drugs include class 1A and III antiarrhythmics, macrolide antibiotics, pentamidine, antimalarials, antipsychotics, arsenic trioxide, and methadone. Treatment for TdP includes immediate defibrillation for hemodynamic instability and intravenous magnesium sulfate. Potassium levels should be maintained in the high normal range, and all QT prolonging agents must be promptly discontinued.

Implication from randomized trials of rate and rhythm controls on management of patients with persistent atrial fibrillation

Recently, several randomized trials were published on the issue of rate or rhythm control for patients with atrial fibrillation (AF). Patients were typically minor symptomatic, relatively old, with age above 70, presenting with a recurrence of AF and suffering from only mild to moderate underlying heart disease. The main outcome of these trials is that rate control is not inferior to rhythm control for the management of patients with AF concerning morbidity and mortality. Also patients' quality of life did not differ significantly in follow-up in these trials. However, rhythm control is not redundant in the treatment of AF. Focus is now on subgroups of patients who could still have benefit being in sinus rhythm. For severely symptomatic patients, patients presenting with the first episode of AF and probably those with severe congestive heart failure, to restore and maintain sinus rhythm should still be the goal. With the failure of antiarrhythmic therapy, nonpharmacological approaches such as pulmonary vein isolation can be performed. Another finding of the randomized trials is that being in sinus rhythm does not prevent from the occurrence of thromboembolic complications. This means that for patients with AF, with risk factors for thromboembolic events, adequate anticoagulant therapy is indicated irrespective of the current heart rhythm. As with antiarrhythmic therapy, the search for new and safer anticoagulant therapy is underway. This review will focus on the key aspects we have learned from the randomized trials on rate and rhythm controls for patients with AF.

Sustained torsade de pointes occurring early during oral sotalol therapy for atrial fibrillation recurrence prophylaxis in a patient without heart disease

This report describes a 64 year-old female patient admitted to our department for recurrent and symptomatic episodes of atrial fibrillation. Antiarrhythmic therapy with sotalol at 240 mg/day was started, and after 48 h the patient experienced several episodes of sustained torsade de pointes, dramatic marked QT interval prolongation and negative T wave, in absence of overt cardiac disease, renal failure, electrolyte abnormalities or baseline QT interval prolongation. This case emphasizes the importance of hospitalization at the starting of sotalol therapy, especially in female patients, even in absence of predisposing factors for drug-induced tachyarrhythmias.

A benefit–risk assessment of class III antiarrhythmic agents

The prevalence of arrhythmia in the population is increasing as more people survive for longer with cardiovascular disease. It was once thought that antiarrhythmic therapy could save life, however, it is now evident that antiarrhythmic therapy should be administrated with the purpose of symptomatic relief. Since many patients experience a decrease in physical performance as well as a diminished quality of life during arrhythmia there is still a need for antiarrhythmic drug therapy. The development of new antiarrhythmic agents has changed the focus from class I to class III agents since it became evident that with class I drug therapy the prevalence of mortality is considerably higher. This review focuses on the benefits and risks of known and newer class III antiarrhythmic agents. The benefits discussed include the ability to maintain sinus rhythm in persistent atrial fibrillation patients, and reducing the need for implantable cardioverter defibrillator shock/antitachycardia therapy, since no class III antiarrhythmic agents have proven survival benefit. The risks discussed mainly focus on pro-arrhythmia as torsade de pointes ventricular tachycardia.

Old and new antiarrhythmic drugs for converting and maintaining sinus rhythm in atrial fibrillation: comparative efficacy and results of trials

In managing atrial fibrillation (AF), the main therapeutic strategies include rate control, termination of the arrhythmia, and the prevention of recurrences and thromboembolic events. Safety and efficacy considerations are important in optimizing the choice of an antiarrhythmic drug for the treatment of AF. Recently approved antiarrhythmics, such as dofetilide, and promising investigational drugs, such as azimilide and dronedarone, may change the treatment landscape for AF. For medical conversion of recent-onset AF, class IC antiarrhythmic drugs, administered as an oral bolus, have been demonstrated to be the most efficacious pharmacologic conversion agents. Intravenous ibutilide and oral dofetilide both have efficacies superior to placebo in controlled trials for converting persistent AF. Comparative trials in paroxysmal AF have demonstrated that flecainide, propafenone, quinidine, and sotalol are equally effective in preventing recurrences of AF. Amiodarone has been demonstrated to be more efficacious than propafenone or sotalol in the Canadian Trial of Atrial Fibrillation. In persistent AF, twice-daily dofetilide has been shown to be as or more effective than low-dose sotalol given twice daily for the maintenance of sinus rhythm in patients with AF. Trials have demonstrated that subjective adverse effects are less frequent with class IC drugs, sotalol, and dofetilide compared with such drugs as quinidine. In patients without structural heart disease, flecainide, propafenone, and D,L-sotalol are the initial drugs of choice, given their reasonable efficacy, low incidence of subjective side effects, and lack of significant end-organ toxicity. Treating AF in patients with left ventricular dysfunction can be difficult because of associated electrophysiologic derangements, potential proarrhythmic concerns, and negative inotropic effects of antiarrhythmics. Some data exist suggesting that angiotensin-converting enzyme inhibitors and angiotensin receptor blockers can prevent AF either by preventing atrial dilation and stretch-induced arrhythmias or by blocking the renin-angiotensin system. In post-myocardial infarction patients, D,L-sotalol, dofetilide, and amiodarone-and in congestive heart failure patients, amiodarone and dofetilide-have demonstrated neutral effects on survival in controlled trials. In the Congestive Heart Failure Survival Trial of Antiarrhythmic Therapy (CHF-STAT), amiodarone lowered the frequency of AF development and improved left ventricular ejection fraction over time. In CHF-STAT, there was lower mortality in patients who converted from AF to sinus rhythm. Dofetilide decreased rehospitalization for congestive heart failure in the Danish Investigations of Arrhythmia and Mortality on Dofetilide (DIAMOND) trials. Neutral effects on survival and favorable hemodynamics have positioned amiodarone and dofetilide as the antiarrhythmics of choice in patients with left ventricular dysfunction. In post-myocardial infarction patients, sotalol is an additional agent to consider for treatment of AF in this setting.

Risk of proarrhythmia with class III antiarrhythmic agents: sex-based differences and other issues

Although men have a higher risk of atrial fibrillation compared with women, the absolute number of women with atrial fibrillation is greater. Congestive heart failure increases the risk of developing atrial fibrillation in women more than in men, and the prognosis for women with atrial fibrillation is worse than for men. The longer baseline corrected QT interval in women is well known. The mechanism is likely the result of increased circulating androgens, causing the QT interval to shorten in men after puberty. Female sex is associated with an increased risk of torsades de pointes in the setting of potassium antagonists. Class III antiarrhythmic drugs are frequently used for the treatment of atrial fibrillation in heart failure patients because of their neutral effect on mortality and their tolerance by patients with low ejection fractions. Although amiodarone and azimilide carry a low potential for producing torsades de pointes compared with sotalol and dofetilide, the prevalence of torsades de pointes in women is at least twice that in men for all these drugs. Careful monitoring of the QT interval and potassium level, as well as control of congestive heart failure, can help reduce the risk of proarrhythmia. Avoidance of polypharmacy with other potassium antagonists and unmonitored drug formulation changes are important in the management of all patients taking class III agents, but they are particularly crucial in women with additional risk factors for torsades de pointes.

Amiodarone and the risk of bradyarrhythmia requiring permanent pacemaker in elderly patients with atrial fibrillation and prior myocardial infarction

OBJECTIVES

The aim of this study was to determine whether the use of amiodarone in patients with atrial fibrillation (AF) increases the risk of bradyarrhythmia requiring a permanent pacemaker.

BACKGROUND

Reports of severe bradyarrhythmia during amiodarone therapy are infrequent and limited to studies assessing the therapy's use in the management of patients with ventricular arrhythmias.

METHODS

A study cohort of 8,770 patients age > or =65 years with a new diagnosis of AF was identified from a provincewide database of Quebec residents with a myocardial infarction (MI) between 1991 and 1999. Using a nested case-control design, 477 cases of bradyarrhythmia requiring a permanent pacemaker were matched (1:4) to 1,908 controls. Multivariable logistic regression was used to estimate the odds ratio (OR) of pacemaker insertion associated with amiodarone use, controlling for baseline risk factors and exposure to sotalol, Class I antiarrhythmic agents, beta-blockers, calcium channel blockers, and digoxin.

RESULTS

amiodarone use was associated with an increased risk of pacemaker insertion (OR: 2.14, 95% confidence interval [CI]: 1.30 to 3.54). This effect was modified by gender, with a greater risk in women versus men (OR: 3.86, 95% CI: 1.70 to 8.75 vs. OR: 1.52, 95% CI: 0.80 to 2.89). Digoxin was the only other medication associated with an increased risk of pacemaker insertion (OR: 1.78, 95% CI: 1.37 to 2.31).

CONCLUSIONS

This study suggests that the use of amiodarone in elderly patients with AF and a previous MI increases the risk of bradyarrhythmia requiring a permanent pacemaker. The finding of an augmented risk of pacemaker insertion in elderly women receiving amiodarone requires further investigation.

Maintaining stability of sinus rhythm in atrial fibrillation: antiarrhythmic drugs versus ablation

In managing atrial fibrillation, the main therapeutic strategies include rate control, termination of the arrhythmia, and pr vention of recurrences and thromboembolic events. Rate control with digoxin, b-blockers, verapamil, and diltiazem may be preferred in drug refractory and sedentary patients with markedly dilated left atrium and atrial fibrillation of long duration. Drugs useful in the maintenance of sinus rhythm include quinidine, procainamide, disopyramide, sotalol, amiodarone, dofetilide, flecainide, and propafenone. In patients with structural heart disease, the class III antiarrhythmics are the initial drugs of choice, given their neutral effects on survival in a post-myocardial infarction and congestive heart failure population. Due to high recurrence rates with pharmacologic therapy, nonpharmacologic options of therapy include atrioventricular junction ablation, atrial defibrillators, catheter ablation of pulmonary vein foci, and attempts to perform an atrial Maze procedure using catheters. Hybrid therapy using drugs in combination with nonpharmacologic approaches will be used more frequently in the future for refractory patients.

A review of class III antiarrhythmic agents for atrial fibrillation: maintenance of normal sinus rhythm

A noteworthy shift from class I to class III antiarrhythmic agents for suppression of atrial fibrillation has occurred. Sotalol, amiodarone, and dofetilide have been evaluated for their ability to maintain sinus rhythm in patients with chronic atrial fibrillation. All of these agents are moderately effective; however, amiodarone appears to be most efficacious. Aside from their common class III actions, these agents have profoundly different pharmacologic, pharmacokinetic, safety, and drug interaction profiles that help guide drug selection. Amiodarone and dofetilide are safe in patients who have had a myocardial infarction and those with heart failure. The safety of commercially available d,l-sotalol in these patients is poorly understood. Torsades de pointes is the most serious adverse effect of sotalol and dofetilide, and risk increases with renal dysfunction. Amiodarone has minimal proarrhythmic risk but has numerous noncardiac toxicities that require frequent monitoring. Overall, an ideal antiarrhythmic agent does not exist, and drug selection should be highly individualized.

Sotalol in treatment of pediatric cardiac arrhythmias

BACKGROUND

There is limited experience on sotalol use in the management of childhood arrhythmias. This study reviews the results of our experience with oral sotalol for treatment and prevention of tachyarrhythmias in children.

METHODS

The records of 62 patients (27 female, 35 male, mean age: 8.5+/-5.3 years) treated with sotalol for supraventricular or ventricular arrhythmias from 1994 to 1999 at our institution were reviewed. Demographic, clinical, echocardiographic, electrocardiographic (ECG), ambulatory ECG and electrophysiologic variables were collected.

RESULTS

Forty-two (63.6%) patients had re-entrant supraventricular tachycardia, eight patients (12.9%) had atrial tachycardia, one patient (1.6%) had junctional ectopic tachycardia, four patients (6.5%) had ventricular tachycardia, and seven patients (11.3%) had complex ventricular arrhythmias, as evidenced by surface or ambulatory ECG records; or revealed during the electrophysiological study. The mean sotalol dose was 3.9+/-1.2 mg/kg per day. In 15.5+/-13.9 months of sotalol use 50% (n=31) had complete relief of symptoms and/or arrhythmia and 29% (n=18) had partial relief. Sotalol was ineffective in 20% (n=13). Sotalol was more effective in re-entrant type supraventricular tachycardias (P=0.012). Sotalol was the first choice in 35.5% of patients. The sotalol therapy was initiated in inpatient settings in 40.3% (25 patients). Complications due to sotalol were seen in six patients (five patients developed bradycardia/pauses, and one patient had torsades de pointes) for which the sotalol dose was modified. In patients with sick sinus syndrome, a pacemaker was implanted and in another patient sotalol was stopped.

CONCLUSION

Sotalol, being an effective and safe drug particularly in children, is a good therapeutic alternative for the preventive treatment of childhood tachyarrhythmias.

Long-term efficacy and safety of propafenone and sotalol for the maintenance of sinus rhythm after conversion of recurrent symptomatic atrial fibrillation

This study was performed to evaluate, using a randomized double-blind, placebo-controlled protocol, the long-term efficacy and safety of propafenone and sotalol in maintaining sinus rhythm after conversion of recurrent symptomatic atrial fibrillation (AF). The maintenance of sinus rhythm in patients with recurrent AF has several potential benefits, the most important being a reduced risk of thromboembolic events. Three hundred patients with recurrent AF (> or = 4 episodes in the last year) and AF at enrollment lasting < 48 hours were randomized to receive either propafenone (mean daily dose 13 +/- 1.5 mg/kg; 102 patients), sotalol (mean daily dose 3 +/- 0.4 mg/kg; 106 patients), or placebo (92 patients). After 1-year follow-up, Kaplan-Meier estimates of the proportion of patients remaining in sinus rhythm were comparable between propafenone (63%) and sotalol (73%) and superior to placebo (35%; p = 0.001 vs both drugs). Symptomatic recurrences occurred later with propafenone and sotalol than with placebo. Nine patients (9%) in the propafenone group, 11 (10%) in the sotalol group, and 3 (3%) in the placebo group discontinued therapy due to adverse effects. Malignant nonfatal arrhythmias due to proarrhythmic effects were documented with sotalol only, and occurred < 72 hours from the beginning of therapy in 4 patients (4%). During recurrences, the ventricular rate was significantly reduced in patients taking propafenone and sotalol (p = 0.001 for both drugs vs placebo). The likelihood of remaining in sinus rhythm during follow-up was higher in younger patients with smaller left atrial size and without concomitant heart disease. In patients with recurrent symptomatic AF, propafenone and sotalol are not significantly different from each other and are superior to placebo in maintaining sinus rhythm at 1 year. Recurrences occur later and tend to be less symptomatic with propafenone and sotalol compared with placebo.

Inpatient or outpatient initiation of antiarrhythmic medications: why the controversy?

The decision of whether to initiate antiarrhythmic medications in or out of the hospital for patients with atrial fibrillation remains an issue of significant controversy. The current review analyzes the available data pertaining to the safety of antiarrhythmic agent initiation in patients with atrial fibrillation and provides a practice guideline.

Advances in cardiac electrophysiology and pacing

Significant advances have been made in the management of cardiac arrhythmias. New technology has enhanced the ability to understand and treat a variety of tachycardias. Excitement and caution surround ablative approaches for atrial fibrillation. The role of ICDs and class III antiarrhythmic drugs in the management of patients at risk for sudden cardiac death has been clarified. A new indication for cardiac pacing is evolving as a supplemental treatment for patients with refractory congestive heart failure. These and other advances provide numerous exciting options for management of cardiac patients.

Cost effectiveness of therapies for atrial fibrillation. A review

Atrial fibrillation is the most common supraventricular tachyarrhythmia encountered in clinical practice, affecting over 5% of persons over the age of 65 years. A common pathophysiological mechanism for arrhythmia development is atrial distention and fibrosis induced by hypertension, coronary artery disease or ventricular dysfunction. Less frequently, atrial fibrillation is caused by mitral stenosis or other provocative factors such as thyrotoxicosis, pericarditis or alcohol intoxication. Depending on the extent of associated cardiovascular disease, atrial fibrillation may produce haemodynamic compromise, or symptoms such as palpitations, fatigue, chest pain or dyspnoea. Arrhythmia-induced atrial stasis can precipitate clot formation and the potential for subsequent thromboembolism. Comprehensive management of atrial fibrillation requires a multifaceted approach directed at controlling symptoms, protecting the patient from ischaemic stroke or peripheral embolism and possible conversion to or maintenance of sinus rhythm. Numerous randomised trials have demonstrated the efficacy of warfarin--and less so aspirin (acetylsalicylic acid)--in reducing the risk of embolic events. Furthermore, therapeutic strategies exist that can favourably modify symptoms by restoring and maintaining sinus rhythm with cardioversion and antiarrhythmic prophylaxis. However, the risks and benefits of various treatments is highly dependent on patient-specific features, emphasising the need for an individualised approach. This article reviews the findings of cost-effectiveness studies published over the past decade that have evaluated different components of treatment strategies for atrial fibrillation. These studies demonstrate the economic attractiveness of acute management options, long term warfarin prophylaxis, telemetry-guided initiation of antiarrhythmic therapy, approaches to restore and maintain sinus rhythm, and the potential role of transoesophageal echocardiographic screening for atrial thrombus prior to pharmacological or electrical cardioversion. Further, we discuss the merits and limitations of the cost-effectiveness analyses in the context of overall treatment strategies. Finally, we identify areas that will require additional research to achieve the goal of effective and economically efficient management of atrial fibrillation.

Management of arrythmias

The management of arrhythmias in elderly patients with congestive heart failure, including atrial fibrillation, ventricular tachyarrhythmias, and bradyarrhythmias, is described. Patients with atrial fibrillation can be treated with rate control anticoagulation for stroke prevention or by attempt at cardioversion and maintenance of sinus rhythm. Elderly patients remaining in atrial fibrillation benefit from anticoagulation provided that no contraindication exists. In patients surviving malignant ventricular arrhythmias, defibrillator implantation is beneficial in elderly patients with heart failure. Prognosis and treatment of nonsustained arrhythmias depends on the presence of underlying cardiac abnormalities. In the healthy elderly population, treatment is not indicated. In patients with coronary artery disease, decreased ejection fraction, and nonsustained ventricular tachycardia, electrophysiology can further stratify risk, and defibrillator implantation can improve survival if arrhythmias are induced. This benefit is as great in elderly patients as in younger patients. Symptomatic bradycardias are increasingly common with advancing age. Symptoms are improved with pacing, with maximum benefit from physiologic rather than ventricular pacing. Although the elderly population poses a unique challenge when faced with arrhythmias, an active approach not only saves lives but also reduces morbidity.

Inpatient versus outpatient antiarrhythmic drug initiation: safety and cost-effectiveness issues

Debate exists as to the proper site for initiating antiarrhythmic therapy for supraventricular tachyarrhythmias and other benign forms of ectopy: inpatient versus outpatient. Rapid detection of efficacy and adverse effects, with immediate correction of the latter, favors the inpatient site. Convenience and, under most circumstances, lower cost favor the outpatient site. Circumstances under which adverse event rates, including proarrhythmia, are expectedly low, would favor outpatient initiation. So would the use of an agent whose elimination half-life is so long as to render in-hospital monitoring to steady state highly impractical. Accordingly, outpatient initiation would be suitable for patients without structural heart disease receiving class IC drugs, patients with low risk for torsades de pointes receiving selected class III agents, in whom data in the literature are supportive (as has occurred with sotalol and azimilide), and patients who are to receive amiodarone. Transtelephonic electrocardiographic monitoring can be used to facilitate assessment in the outpatient setting. Inpatient initiation should be considered for patients with underlying sinus node or atrioventricular conduction disturbances, for patients with significant structural heart disease, for patients receiving a drug whose proarrhythmia may be idiosyncratic (e.g., quinidine), and for patients who are to begin an antiarrhythmic drug while in a supraventricular tachyarrhythmia in whom sinus rhythm has not previously been seen. The relative costs and benefits of the approach chosen will be a reflection of the probability that a drug with a chosen mechanism will cause an adverse outcome in a patient with a specific clinical substrate during the period chosen for monitoring.

Efficacy and safety of sotalol versus quinidine for the maintenance of sinus rhythm after conversion of atrial fibrillation. SOCESP Investigators. The Cardiology Society of São Paulo

To compare the efficacy and safety of sotalol and quinidine after conversion of atrial fibrillation (AF) of <6 months, a prospective multicenter trial enrolled 121 patients who were randomized to receive dl-sotalol (160 to 320 mg/day, 58 patients) or quinidine sulfate (600 to 800 mg/day, 63 patients). Patients with left ventricular ejection fraction of <0.40 or left atrial diameter >5.2 cm were excluded. After 6 months of follow-up, using the Kaplan-Meier method, the probabilities of success were comparable between sotalol (74%) and quinidine (68%), but recurrences occurred later with sotalol than with quinidine (69 vs 10 days, p <0.05). Four patients developed proarrhythmic events, 3 (5%) with sotalol and 1 (2%) with quinidine, which were all associated with diuretic therapy. In patients converted from recent-onset AF (< or = 72 hours), sotalol was more effective than quinidine (93% vs 64%, p = 0.01), whereas in chronic AF (> 72 hours), quinidine was more effective than sotalol (68% vs 33%, p <0.05). During recurrences, the ventricular rate was significantly reduced in patients taking sotalol (98 to 82 beats/min, p <0.05). Independent predictors of therapeutic success were recent-onset AF in the sotalol group (p <0.001) and absence of hypertension in the quinidine group (p <0.05). In conclusion, sotalol and quinidine have comparable efficacy and safety for the maintenance of sinus rhythm in the overall group. In recent-onset AF, sotalol was more effective, whereas in chronic AF, quinidine had a better result. Recurrences occurred later with sotalol when compared with quinidine. Because of proarrhythmia, these drugs should be used judiciously in patients on diuretic therapy.

Pharmacotherapy of atrial fibrillation

Atrial fibrillation (AF) remains a widespread health problem and the drugs available for its treatment suffer from several drawbacks, including potentially lethal proarrhythmia, serious non-cardiac toxicity and limited efficacy. The evidence for efficacy of currently available anti-arrhythmic agents for sinus rhythm restoration and maintenance is reviewed, with emphasis on randomised trials when available. The current approach to thromboembolism prophylaxis in AF is summarised.

Maintenance of sinus rhythm with oral d,l-sotalol therapy in patients with symptomatic atrial fibrillation and/or atrial flutter. d,l-Sotalol Atrial Fibrillation/Flutter Study Group

Currently d,l-sotalol is widely used to prevent recurrence of atrial fibrillation and/or atrial flutter, although a randomized dose-response study has not previously been conducted to guide therapy for this indication. This study summarizes findings of a double-blind, placebo-controlled, multicenter, randomized trial evaluating the efficacy, safety, and dose-response relation of 3 fixed doses of d,l-sotalol (80, 120, and 160 mg twice daily) for the maintenance of sinus rhythm in 253 patients with atrial fibrillation and/or atrial flutter. All patients were in sinus rhythm at randomization. Treatment (69 patients on placebo, 59 on 80 mg, 63 on 120 mg, and 62 on 160 mg given twice daily) was continued for 12 months or until documented recurrence of symptomatic atrial fibrillation and/or flutter. Transtelephonic electrocardiographic monitoring was used to detect symptomatic recurrences. Demographic characteristics were not different in the 4 groups. Structural heart disease was present in 57% of patients. Patients with a history of heart failure were excluded. The time from randomization to symptomatic arrhythmia recurrence was significantly longer in the 2 higher d,l-sotalol dose groups than in the placebo group. The median times to recurrence were 27, 106, 229, and 175 days for the placebo, 80, 120, and 160 mg groups, respectively. There were no deaths or cases of torsade de pointes, sustained ventricular tachycardia, or ventricular fibrillation reported. Thus, d,l-sotalol appeared to be both safe and effective in maintaining sinus rhythm in patients with symptomatic atrial fibrillation and/or flutter. Further, the 120-mg twice daily dose appeared to provide the most favorable benefit and/or risk.