Table 2.

The treatment of choices for fetal tachyarrhythmias [43, 44]

Parameter	Digoxin	Flecainide	Sotalol	Amiodarone
Indication	Paroxymal SVT, short VA SVT, nonhydropic fetuses	SVT with NIHF, refractory SVT, SVT with heart failure unresponsive to soltalol and digoxin	AF, SVT	SVT resistant to digoxin, AF
Dose	Loading: 1.5–2 mg over 24–48 h; Maintenance: 0.375–1 mg/day	Loading: 200–300 mg divided b.i.d., or t.i.d.; Maintenance: 450 mg/day if no response	Loading: 160–320 mg divided b.i.d.; Maintenance: increased to 480 mg/day	Loading: 1600–2400 mg/day 2–4 times per day; Maintenance: 200–400 mg/day b.i.d.
Route	p.o., or i.v.	p.o.	p.o.	p.o., or i.v.
Fetal/maternal serum level (%)	40–90			10–50
Advantage	Safe and effective		Not accumulate in fetus, not cause intrauterine growth retardation	Little or no negative inotropic effect
Adverse effect	Digoxin monotherapy showed a lower effective rate than combined; Hydropic fetuses refractory to digoxin	Intrauterine death	Negative inotropic effect, intrauterine death	Arrhythmogenic effect, fetal thyroid functional impairement, maternal thrombocytopenia and skin rash

AF atrial flutter, NIHF nonimmune hydrops fetalis, SVT supraventricular tachycardia, VA ventrioatrial conduction