Neonatal radiofrequency catheter ablation of junctional tachycardias

Catheter ablation of typical right atrial flutter in a 20-day-old neonate with tachycardiomyopathy

Background

Fetal echocardiography can diagnose neonatal atrial flutter, which can cause heart failure in newborns. Little is known about catheter ablation in this population.

Methods

Case report that aimed to review a successful ablation in a 20-day-old patient with refractory atrial flutter.

Results

This is the first report of a successful neonatal atrial flutter ablation without any early recurrence after the procedure.

Conclusions

Atrial flutter ablation performed on newborns is a reliable and long-lasting treatment option.

Radiofrequency catheter ablation of intractable ventricular tachycardia in an infant following arterial switch operation

A full-term male neonate presented with cyanosis upon delivery and was subsequently diagnosed with d-transposition of the great arteries, ventricular septal defect, and restrictive atrial septal defect. Following initiation of intravenous prostaglandins and balloon atrial septostomy, an arterial switch operation was performed on day 3 of life. The postoperative course was complicated by intractable ventricular tachycardia that was refractory to lidocaine, amiodarone, esmolol, fosphenytoin, and mexiletine drug therapy. Ventricular tachycardia was suppressed with overdrive atrial pacing but recurred upon discontinuation. Seven weeks postoperatively, radiofrequency catheter ablation was performed due to hemodynamically compromising persistent ventricular tachycardia refractory to medical therapy. The ventricular tachycardia was localized to the inferior-lateral right ventricular outlet septum. The procedure was successful without complications or recurrence. Antiarrhythmics were discontinued after the ablation procedure. Seven days after the ablation, a different, slower fascicular rhythm was noted to compete with the infant's sinus rhythm. This was consistent with the preablation amiodarone having reached subtherapeutic levels given its very long half-life. The patient was restarted on oral beta blockers and amiodarone. The patient was subsequently discharged home in predominantly sinus rhythm with intermittent fascicular rhythm.

Transcatheter cryotherapy for the treatment of supraventricular tachyarrhythmias in children: A single center experience

INTRODUCTION

Transcatheter cryotherapy is an emerging technology for the treatment of children with supraventricular tachyarrhythmias. Limited data exist regarding the use of cryoablation therapy in children. We report a single center's experience with transcatheter cryoablation in the pediatric population.

METHODS AND RESULTS

A retrospective review of demographic, procedural and outcome data was performed for patients undergoing cryoablation for treatment of supraventricular tachycardia (SVT). A historical control group was taken from the 3 years preceding the introduction of cryoablation. Between August 2003 and November 2005, 83 cryoablation procedures were performed in 81 patients (age: 4 to 21 years, mean: 13.4 years) for AV nodal reentrant tachycardia (AVNRT--53), AV reentrant tachycardia (AVRT--20), ectopic atrial tachycardia (EAT--9), and junctional ectopic tachycardia (JET--1). The acute success rate for all procedures was 88% (AVNRT: 96%, AVRT: 85%, EAT: 55%, and JET: 100%). Of 72 patients that underwent successful cryoablation, nine experienced recurrence of SVT (12.5%). The control group consisted of 73 patients (AVNRT--60, AVRT--13). There were no differences in demographic data between the two groups. The overall success rate for the RFA group (96%) was identical to that for patients with AVNRT and AVRT undergoing cryoablation. The recurrence rate for RFA (10%) was less but not significantly different than that for cryoablation (12%). There were no complications in either group.

CONCLUSIONS

Cryoablation is a safe and effective alternative for the treatment of SVT in children.

Transcatheter cryothermal ablation of junctional ectopic tachycardia in the normal heart

BACKGROUND

Junctional ectopic tachycardia in the normal heart is rare and often is resistant to pharmacologic management. Transcatheter ablation using radiofrequency energy places the AV node at risk.

OBJECTIVES

The purpose of this study was to report our experience with transcatheter cryothermal ablation using three-dimensional mapping in six patients with junctional ectopic tachycardia.

METHODS

A review of clinical and electrophysiologic data was performed on all patients with structurally normal hearts who underwent cryothermal ablation for treatment of junctional ectopic tachycardia at two institutions.

RESULTS

Six patients (age 7.7-36.5 years) underwent attempted transcatheter cryothermal ablation using three-dimensional mapping. Only one patient had achieved arrhythmia suppression on medical management. Cryothermal mapping (-30 degrees C) localized the junctional focus while normal conduction was monitored. The junctional focus was high in the triangle of Koch in four patients and was low in one patient. The sixth patient had only one run of junctional ectopic tachycardia during the procedure and therefore received an empiric cryoablation (-70 degrees C) lesion. Subsequent cryoablation lesions were delivered at and around the junctional focus. In one patient, cryomapping eliminated the junctional focus but resulted in transient complete AV block; therefore, cryoablation was not performed. All patients who received the cryoablation lesions had elimination of their junctional ectopic tachycardia at 6-week follow-up. The patient who did not receive a cryoablation lesion remained in a slower junctional rhythm at follow-up.

CONCLUSION

Cryoablation of junctional ectopic tachycardia is safe and effective. Nonetheless, proximity to the His-Purkinje system may preclude success. Empiric cryoablation can be effective; cryotherapy may not yield immediate success, but a delayed salutary effect can follow.

Low-energy radiofrequency catheter ablation as therapy for supraventricular tachycardia in a premature neonate

A premature neonate with hydrops was born at 32 weeks of gestation after successful direct fetal amiodarone therapy via cordocentesis for incessant supraventricular tachycardia. After birth the tachycardia could not be controlled despite high doses of amiodarone and flecainide and the patient developed severe respiratory and circulatory failure. After 3 weeks, weighing 2 kg, he underwent successful and uncomplicated catheter ablation of a left free-wall accessory pathway using low-energy radiofrequency.

CONCLUSION

radiofrequency catheter ablation is rarely used in neonates, but when used with caution may provide the optimal treatment.

Supraventricular tachycardia in the neonate and infant

Supraventricular tachycardia (SVT) is the most common sustained arrhythmia to present in the neonatal and infancy age group. Predisposing factors (congenital heart disease, drug administration, illness and fever) occur only in 15% of infants. The presentation of SVT in the neonate is frequently subtle, and may include pallor, cyanosis, restlessness, irritability, feeding difficulty, tachypnea, diaphoresis and grunting. Congestive heart failure is more common in infants under 4 months of age (35% incidence). Age-related differences in the distribution of SVT mechanisms occur in different age groups. In infants under 1 year of age, the mechanisms underlying SVT are atrial tachycardia (15%), AV nodal re-entry tachycardia (5%), and AV reciprocating tachycardia (80%). Options for acute management include: use of the diving reflex, intravenous adenosine, transesophageal pacing, and cardioversion. Intravenous administration of verapamil should be avoided. Data regarding freedom from recurrence of untreated SVT in the first year of life are limited, and may be in the range of 25-60%. Chronic therapy with digoxin, beta-blockers, flecainide, sotalol and amiodarone has proved effective in controlling recurrent episodes of SVT. Radiofrequency ablation can be employed successfully in medically refractory cases, but should be avoided in this age group (increased complication rate).