Sotalol for atrial tachycardias after surgery for congenital heart disease

"Second line medications" for supraventricular arrhythmias in children: In-hospital efficacy and adverse events during treatment initiation of sotalol and flecainide

INTRODUCTION

Sotalol and flecainide are used as second line agents in children for the treatment of supraventricular arrhythmias (SA) refractory to anti-beta adrenergic antiarrhythmics or digoxin. Efficacy and adverse events in this cohort have not been well described. Here, we report our institutional experience of second line treatment initiation for SA in children.

METHODS AND RESULTS

Utilizing an institutional database, 247 patients initiated on sotalol and 81 patients initiated on flecainide were identified. Congenital heart disease (CHD) was present in 40% of patients. Arrhythmia-free discharge on single or dual agent therapy (in combination with other antiarrhythmics) was 87% for sotalol and 91% for flecainide. Neither age, sex, dosing, presence of CHD nor arrhythmia subtype were associated with alterations in in-hospital efficacy. Compared to baseline, QTc intervals in sotalol patients (436 [416-452 ms] vs. 415 [400-431 ms], p < .01) and QRS intervals in flecainide patients (75 [68-88 ms] vs. 62 [56-71 ms], p < .01) were prolonged. Dose reduction or discontinuation due to QRS prolongation occurred in 9% of patients on flecainide. QTc prolongation resulting in dose reduction/discontinuation of sotalol was encountered in 9 patients (4%) and death with documented torsade de pointes in 2 patients (1%), with 9 of 11 patients having underlying CHD.

CONCLUSION

In children requiring second line agents for treatment of SA, both sotalol and flecainide appear to be highly efficacious. Although predominantly safe in otherwise healthy patients, electrocardiogram changes can occur and children with underlying cardiac disease may have an increased risk of adverse events and rhythm-related side effects during initiation.

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.

Update on Management of Postoperative Atrial Fibrillation After Cardiac Surgery

Postoperative atrial fibrillation (POAF) after cardiac surgery remarkably remains the most prevalent event in perioperative cardiac surgery, having great clinical and economic implications. The purpose of this study is to present recommendations based on international evidence and adapted to our clinical practice for the perioperative management of POAF. This update is based on the latest current literature derived from articles and guidelines regarding atrial fibrillation.

Drug Therapy in Adult Congenital Heart Disease

Adults with congenital heart disease are at risk for atrial and ventricular arrhythmias that can lead to an increased morbidity as well as mortality. When catheter ablation is not an option or unsuccessful, antiarrhythmic drugs are the mainstay of treatment. There is limited data on the use of antiarrhythmics in this population. The purpose of this article is to discuss the practical aspects of the use of antiarrhythmics in adults with congenital heart disease. Several tables have been provided to provide clinicians a reference for daily use.

Atrial Fibrillation in Patients with Congenital Heart Disease

Advances in surgical techniques have led to the survival of most patients with congenital heart disease (CHD) up to their adulthood. During their lifetime, many of them develop atrial tachyarrhythmias due to atrial dilatation and scarring from surgical procedures. More complex defects and palliative repairs are linked to a higher incidence and earlier occurrence of arrhythmias. Atrial fibrillation (AF) is common in patients who have atrial septal defects repaired after age 55 and in patients with tetralogy of Fallot repaired after age 45. Patients with dextrotransposition of the great arteries who undergo Mustard or Senning atrial switch procedures have an increased risk of atrial flutter due to atrial baffle suture lines. Patients with Ebstein's anomaly are also prone to supraventricular tachycardias caused by accessory bypass tracts. Patients with a single ventricle who undergo Fontan palliation are at risk of developing persistent or permanent AF due to extreme atrial enlargement and hypertrophy. In addition, obtaining vascular access to the pulmonary venous atrium can present unique challenges during radiofrequency ablation for patients with a Fontan palliation. Patients with cyanotic CHD who develop AF have substantial morbidity because of limited hemodynamic reserve and a high viscosity state. Amiodarone is an effective therapy for patients with arrhythmias from CHD, but its use carries long-term risks for toxicity. Dofetilide and sotalol have good short-term effectiveness and are reasonable alternatives to amiodarone. Pulmonary vein isolation is associated with better outcomes in patients taking antiarrhythmic medications. Anticoagulants are challenging to prescribe for patients with CHD because of a lack of data that can be extrapolated to this patient population. Surgical ablation is the gold standard for invasive rhythm control in patients with CHD and should be considered at the time of surgical repair or revision of congenital heart defects. When possible, patients with complex CHD should be referred for care to an adult congenital heart disease center of excellence.

Outcomes of Direct Current Cardioversion in Adults With Congenital Heart Disease

Few data exist on direct current cardioversion (DCCV) in adult patients with congenital heart disease (CHD). This is a retrospective case-control study of 279 adults with CHD and 279 adults without CHD (control group) who had elective DCCV for atrial arrhythmias at Mayo Clinic, 2001 to 2013. Control patients were matched by gender and arrhythmia type. The objective was to compare DCCV procedural failure (failure to terminate the presenting arrhythmia) and arrhythmia recurrence (AR). In the CHD group (mean age 55 ± 20 years; men 166 [59%]), the most common diagnosis was Fontan palliation (61; 22%). Transesophageal echocardiography was performed before DCCV in 216 patients (77%); 162 (58%) had atrial flutter, and 117 (42%) had atrial fibrillation. Procedural failure and AR between the case and the control groups were more common in the CHD group (14% vs 7%, p = 0.01) and (83% vs 66% at 60 months, p = 0.001) respectively. There were no deaths or thromboembolic complications. The multivariable risk factors for procedural failure were Fontan palliation and spontaneous echocardiographic contrast; the risk factors for AR were Fontan palliation and atrial fibrillation. When patients with Fontan palliation were excluded from the analysis, the outcome of DCCV (failure and recurrence rates) was similar for the CHD and non-CHD groups despite the age difference between the cohorts. In conclusion, the present study showed that DCCV outcomes were similar for CHD and non-CHD patients, with the exception of patients with Fontan palliation.

Dofetilide for atrial arrhythmias in congenital heart disease: a multicenter study

BACKGROUND

Very little is known about use of the class III antiarrhythmic dofetilide in patients with congenital heart disease (CHD).

METHODS

A multicenter retrospective review of experience with dofetilide in CHD patients was undertaken.

RESULTS

Twenty adults with CHD and refractory atrial arrhythmias were treated with dofetilide at four institutions over a 7-year period. Three (15%) experienced adverse effects during in-hospital initiation of dofetilide (two with torsade de pointes, one with excessive QTc prolongation) and were not continued on this therapy. The remaining 17 were discharged taking dofetilide, with either resolved or improved arrhythmia. One was lost to follow-up. Five subsequently discontinued dofetilide due to waning effectiveness, manifest by recurrence of their arrhythmias. Eleven (55%) remained on dofetilide at most recent visit, with a median follow-up of nearly 1 year. Seven of these 11, or 35% of the CHD patients originally started on dofetilide, experienced a complete resolution of their arrhythmia. The remaining four had breakthrough episodes of atrial arrhythmia, but remained on dofetilide. No patient experienced torsade de pointes after the in-hospital initiation period.

CONCLUSIONS

Used appropriately, dofetilide appears to be a viable adjunct to catheter-based ablation and alternative pharmacological approaches for the treatment of atrial arrhythmias in adult patients with congenital heart disease.

Sinus node dysfunction and atrial tachycardia after the Fontan procedure: The scope of the problem

Similar to other atrial baffling procedures, the Fontan procedure exposes patients to ongoing morbidity and mortality. The development of the bradycardia-tachycardia syndrome can have adverse effects on already-marginal hemodynamics and ventricular function. Patients with Fontan physiology and sinus node dysfunction can be managed with antibradycardic pacemakers. Atrial arrhythmias after "completion Fontan" are difficult to treat and usually require either antiarrhythmic agents, antitachycardic pacemakers, or radiofrequency catheter ablation of the re-entrant circuit. Successful treatment of atrial flutter occurs in only 50% to 70% of patients. There is a high recurrence rate of atrial flutter with any of the accepted management strategies. Copyright 1998 by W.B. Saunders Company

Pharmacologic management of arrhythmias in patients with congenital heart disease

The management of cardiac arrhythmias has evolved rapidly over the past decade. This includes the development of more effective antiarrhythmic medications as well as catheter- and device-based therapies. Antiarrhythmic medications remain the primary treatment modality for most acute arrhythmias; however, the long term use of these medications may be accompanied by severe adverse effects. For this reason, antiarrhythmic medications are increasingly used in conjunction with other forms of therapy, such as catheter ablation or pacemaker implantation. Patients with congenital heart disease often have an increased propensity for cardiac arrhythmias due to both inherent conduction system abnormalities and impaired ventricular function. The purpose of this review is to examine the currently available antiarrhythmic drugs and assess their role in the treatment of arrhythmias in patients with congenital heart disease. It is important to emphasize that patients with congenital heart disease often have hemodynamic limitations and may be at an increased risk for developing adverse effects with antiarrhythmic agents. An awareness of the arrhythmias associated with congenital heart disease, the natural history of these arrhythmias, and the potential benefit of treatment with antiarrhythmic medications versus other forms of therapy provides a rational basis for therapy in this challenging population of patients.

Antiarrhythmic drug therapy in the neonate

The neonate presents a challenge for the practitioner considering antiarrhythmic therapy: pharmacokinetics are different than in older children or adults; and the arrhythmia substrate may also differ, with respect to issues of ion channel and autonomic nervous system development. This paper reviews the need for antiarrhythmic drug therapy in the neonate, developmental aspects of pharmacokinetics, autonomic regulation and cellular electrophysiology and the antiarrhythmics available today with an emphasis on newer drug therapy.

Atrial Tachycardia

The available therapies for atrial tachycardia include the use of antiarrhythmic drugs, radiofrequency catheter ablation, and antiarrhythmic surgery. The growing realization that catheter ablation cures atrial tachycardia with high efficacy and safety has contributed to the increasing popularity of the procedure and makes it the therapy of choice in symptomatic patients. Antiarrhythmic drugs are thought to be effective acutely in 40% to 60% of patients, but their long-term efficacy remains poorly defined. Infrequently, atrioventricular nodal catheter ablation combined with pacing may be needed in patients whose arrhythmias are refractory to antiarrhythmic drugs and curative radiofrequency ablation. Antiarrhythmic surgery has a limited role as a therapy of last resort.

[Arrhythmias in patients with congenital heart disease and their impact on prognosis]

Patients with congenital heart disease have an increased chance to suffer from brady- as well as tachyarrhythmias. The impact of these on quality of life, morbidity and mortality is more often imperative as compared to heart-healthy individuals. The substrate for these may be either congenital or acquired. Improvements of the surgical management of these patients have led, on the one hand, to improved survival rates with prolonged life expectancy within the last 2 decades, which on the other hand provided the basis for a higher rate of acquired cardiac arrhythmias. Together, this not only challenges diagnostics and therapy but also the prognostic relevance of these arrhythmias. The therapeutic strategies and prognostic markers have until now mostly been based on retrospective studies limited by the low number of patients and inhomogeneous patient selection. Despite these limitations, an increased risk of sudden cardiac death has been substantiated for certain patient groups, e.g., those operated on by the Mustard- or Senning procedures in patients with transposition of the great arteries and patients operated on with correction of the tetralogy of Fallot. However, until now it has not been possible to identify reliable markers for establishing the risk on an individual basis within these patient cohorts. For achieving reliable data on the symptomatic and prognostic effects of present-day--as well as new-coming--therapeutic strategies, it is mandatory to perform prospectively based, randomized multicenter studies. Furthermore, the well-appreciated synergism of hemodynamically and primarily of arrhythmia-based effects on prognosis could potentially be divided into their relative weight to better guide appropriate, substrate-related therapy. In addition, this should help to get better estimates of the risk for sudden cardiac death in different, etiologically homogeneous, groups of patients with congenital heart disease.