For the acute treatment of supraventricular (SVT) and ventricular tachycardias (VT) in pregnant women, electrical cardioversion with 50-100 J is indicated in all unstable patients. In stable SVT the initial therapy includes vagal maneuvers or intravenous adenosine. For long-term therapy, beta-blocking agents with beta(1)-selectivity are first-line drugs or specific anti-arrhythmic drugs. An implantable cardioverter-defibrillator is another approach. In patients with symptomatic bradycardia, a pacemaker can be implanted using echocardiography at any stage of pregnancy. Evaluation of fetal arrhythmias in clinical practice is based on assessment of the chronological relationship between atrial and ventricular contraction (M-mode and Doppler ultrasound or magnetocardiography). Most forms of SVT can be treated with transplacental administration of anti-arrhythmic drugs. Atrioventricular (AV) block in fetuses with structural heart disease is frequently associated with hydrops fetalis and intrauterine death. Administration of corticoids and beta-mimetic drugs is used to treat antibody-mediated AV block and cardiomyopathy.
