Atrial Flutter in Infants

Arrhythmia management in patients with a common arterial trunk and d-transposition of the great arteries

Arrhythmias in patients with congenital heart disease present a challenge to the care of these patients and can result in significant morbidity and mortality. Transposition of the great arteries and common arterial trunk are no exceptions. It is important to identify risk factors for arrhythmia development in the peri-operative period. The peri-operative arrhythmia burden may relate to the underlying congenital heart disease, haemodynamic perturbations, operative events, and potential residual lesions. In addition, these patients are at risk for developing arrhythmias later in life, and non-invasive and potentially invasive arrhythmia surveillance should be a routine part of the care of these patients. This article highlights important strategies to manage arrhythmia development and prevention in this patient population.

Rapid control of foetal supraventricular tachycardia with digoxin and flecainide combination treatment

OBJECTIVES

To evaluate the efficacy of flecainide and digoxin combination in foetal supraventricular tachycardia.

SETTING

This study was carried out in a tertiary referral centre.

METHODS

We conducted a retrospective review of 29 patients diagnosed with supraventricular foetal tachycardia between 2001 and 2009. Mode of presentation, foetal cardiac function, maternal anti-arrhythmic serum levels, drug tolerance, and maternal electrocardiogram recordings were assessed. The postnatal outcome of each infant was also evaluated for tachycardia recurrence.

RESULTS

In all, 27 foetuses were treated with digoxin and flecainide combination, and two foetuses were delivered without any treatment. Of the 27 foetuses treated, six [corrected] had atrial flutter and the remaining 21 [corrected] had atrioventricular re-entry tachycardia. There were eight foetuses with hydrops (27%), of whom three had atrial flutter and five had atrioventricular re-entry tachycardia; 26 foetuses (96%) responded to flecainide and digoxin combination, with restoration of sinus rhythm in 22 (81.4%) and rate control in the other four. In one severely hydropic foetus, there was no response to treatment. In all, 26 treated infants were delivered alive, but one pregnancy was terminated for non-cardiac causes when the foetus was in sinus rhythm. There was no intrauterine death due to tachycardia. Although there were minor side effects to anti-arrhythmic medications, none of the pregnant women developed proarrhythmia.

CONCLUSION

Flecainide and digoxin combination treatment offers a safe and effective treatment for foetal supraventricular tachycardia with fast restoration of sinus rhythm.

Multiple external electrical cardioversions for refractory neonatal atrial flutter

This report describes a case of atrial flutter in a fetal/neonatal patient who did not respond to adenosine, a propafenone bolus, and three electrical external cardioversions. A fourth direct current cardioversion after propafenone premedication resolved the atrial flutter. The arrhythmia did not recur with propafenone therapy during a 12-month follow-up period.

[Supraventricular tachycardia in infants]

Supraventricular tachycardia in infants are variable. We try to summarize clinical, electrical and treatment particularities of supraventricular arrhythmia in infants. The majority of infants with supraventricular arrhythmia have a good clinical outcome and an excellent prognosis and may not require chronic antiarrhythmic therapy if they had precocious treatment.

Elevated impedance during cardioversion in neonates with atrial flutter

Direct-current cardioversion is a common treatment modality for acute termination of atrial flutter in neonates. Studies in children have demonstrated that cardioversion is often successful with as little as 0.25-0.5 J/kg with the current biphasic devices. We hypothesize that during cardioversion of atrial flutter in neonates, however, the impedance may be high and more energy may be required for successful cardioversion. A retrospective chart review of our institutional experience from 2005 through 2008 was performed. Neonates with atrial flutter requiring cardioversion who had strips available for review were included. Six patients met the inclusion criteria. The median age at the time of cardioversion was 2.6 h (range, 1.3-336 h) and the mean weight was 3.22 +/- 0.4 kg (SD). The mean electrical impedance of the successful shocks was elevated, at 234 +/- 136 Omega. The mean energy delivered for successful cardioversion was 0.9 +/- 0.3 J/kg, and the current was 1 A in all patients. In conclusion, the shock impedance was elevated in the neonates studied during cardioversion of atrial flutter. Low current was sufficient for successful cardioversion. Further studies are needed in this specific population.

Detection and management of life threatening arrhythmias in the perinatal period

The management of tachyarrhythmias and bradyarrythmias in the fetus requires a team approach with careful monitoring of fetal well-being as well as care in establishing a precise diagnosis with use of m-mode and Doppler echocardiography to determine the atrial and ventricular rate. A persistent fetal heart rate less than 80 beats per minute (bpm) suggests complete atrioventricular block. A persistent fetal heart rate over 180 bpm suggests pathological tachycardia, most of which are a supraventricular tachycardia mediated via an accessory pathway. However, around 20% are due to atrial flutter, and this review highlights why medical management should be different for these cases, and for those with hydrops or cardiac failure. It also illustrates which fetus or infant may be at particular risk, and illustrates key features in their management before and after birth.