Amiodarone Therapy for Drug-Refractory Fetal Tachycardia

Abstract

Background-Fetal tachycardia complicated by ventricular dysfunction and hydrops fetalis carries a significant risk of morbidity and mortality. Transplacental digoxin is effective therapy in a small percentage, but there is no consensus with regard to antiarrhythmic treatment if digoxin fails. This study evaluates the safety, efficacy, and outcome of amiodarone therapy for digoxin-refractory fetal tachycardia with heart failure. Methods and Results-Fetuses with incessant tachycardia and either hydrops fetalis (nϭ24) or ventricular dysfunction (nϭ2) for whom digoxin monotherapy and secondary antiarrhythmic agents (nϭ13) were not effective were treated transplacentally with a loading dose of oral amiodarone for 2 to 7 days, followed by daily maintenance therapy for Ͻ1 to 15 weeks. Digoxin therapy was continued throughout gestation. Newborns were studied by transesophageal pacing or ECG monitoring to determine the mechanism of tachycardia. Three fetuses were delivered urgently in tachycardia during amiodarone loading, and 3 required additional antiarrhythmic agents for sustained cardioversion. Amiodarone or amiodarone combinations converted 14 of 15 (93%) with reentrant supraventricular tachycardia, 2 of 2 with ventricular or junctional ectopic tachycardia, and 3 of 9 (33%) with atrial flutter. Amiodarone-related adverse effects were transient in 5 infants and 8 mothers. Mean gestational age at delivery was 37 weeks, with 100% survival. Conclusions-Orally administered amiodarone is safe and effective treatment for drug-refractory fetal tachycardia, specifically reentrant supraventricular tachycardia, junctional ectopic, or ventricular tachycardia, even when accompanied by hydrops fetalis or ventricular dysfunction.

Development and Significance of a Fetal Electrocardiogram Recorded by Signal-Averaged High-Amplification Electrocardiography

“…16) Some studies have successfully detected lethal cardiac arrhythmias with fetal MCGs. 17,18) However, while highly sensitive, such devices are large and unsuitable for ICU and emergency room bedside recordings.…”

Gestão pré-natal e resultados da taquicardia juncional ectópica acelerado e hidropisia

“…Digoxin has been widely accepted as the mainstay of therapy because of its safety and convenient administration 1,2,5 . Flecainide, sotalol and amiodarone has also been used in the treatment of fetal tachyarrhythmias 5,9,10 . However, more serious side effects on both mother and fetus have been a concern 5 .…”

Non-immune hydrops foetalis due to foetal tachyarrhythmia-management with transplacental amiodarone

“…9 Another study on refractory cases of foetal tachycardia reported a success rate of 93% in the treatment of foetal SVT in hydropic foetuses using amiodarone. 10 We used amiodarone as a drug for the first-line of treatment of our patient since hydrops had already developed.…”