Fetal Tachyarrhythmia Management from Digoxin to Amiodarone—A Review

Abstract

Sustained fetal tachycardias are rare but represent a high risk of mortality and morbidity. Consensus has yet to be found regarding their optimal management. The aim of this narrative review is to summarize the data available in the current literature regarding the efficacy and safety of medications used in the management of intrauterine tachyarrhythmias and to provide possible treatment protocols. In this review, we would like to emphasize the importance of a thorough evaluation of both the fetus and the mother, prior to transplacental antiarrhythmic drug initiation. Factors such as the hemodynamic status of the fetus, possible mechanisms of fetal arrhythmia, and concomitant maternal conditions are of primordial importance. As a possible treatment protocol, we would like to recommend the following: due to the risk of sustained supraventricular tachycardia (SVT), fetuses with frequent premature atrial beats should be evaluated more frequently by echocardiography. A careful hemodynamic evaluation of a fetus with tachycardia is primordial in forestalling the appearance of hydrops. In the case of atrial flutter (AFL), sotalol therapy could represent a first choice, whereas when dealing with SVT patients, flecainide should be considered, especially for hydropic patients. These data require consolidation through larger scale, non-randomized studies and should be handled with caution.

Therapeutic drug monitoring on the use of transplacental digoxin in fetal tachyarrhythmia: a case report

“…The recommended dosing regimen for flecainide in FT transplacental therapy is orally 200–300 mg/day, dividing 2 or 3 times a day, and can be increased to 450 mg/day to approach the target plasma range between 0.2 and 1 μg/mL [ 1 5 ]. The amount and frequency for dosing flecainide in the case (100 mg 3 times a day) corresponded with the recommended dosage regimen.…”

“…Although digoxin is preferred in transplacental therapy because of its long history of use for the mother and fetus, there are discrepancies in the first-choice drug for FT treatment [ 5 ]. In a recent systemic review, 4 medications were used as first-line therapy in ten studies: digoxin, flecainide, sotalol, and amiodarone in 54%, 26%, 19%, and 1% of patients, respectively [ 1 ].…”

“…Digoxin is a commonly used antiarrhythmic drug as it has been used for a long with its safety profile for the mother and fetus [ 3 4 5 ]. Digoxin is highly lipophilic and a low molecular weight drug that can rapidly cross the placenta and reach equilibrium [ 6 ].…”

“…Reports reveal its equal maternal and fetal serum concentrations: 60% to 90% of maternal serum levels, or 11% to 26% in cases of hydrops fetalis [ 6 7 ]. Flecainide, sotalol, and amiodarone are generally used as other choices of therapies [ 5 8 ]. Digoxin and flecainide are preferred in cases of fetal supraventricular tachycardia, whereas sotalol is preferred in cases of atrial flutter [ 4 5 ].…”

“…Flecainide, sotalol, and amiodarone are generally used as other choices of therapies [ 5 8 ]. Digoxin and flecainide are preferred in cases of fetal supraventricular tachycardia, whereas sotalol is preferred in cases of atrial flutter [ 4 5 ].…”