We report a case of previously healthy mother who developed postpartum tachyarrhythmia as complication after she received oral sotalol for prenatal diagnosis of fetal supraventricular tachycardia (SVT).
The fetal SVT detected at 21 weeks gestation complicated with congestive heart failure and ascites. There was no structural cardiac defect

Before the initiation of sotalol therapy, maternal electrolytes and ECGs were performed to exclude preexisting arrhythmias
The sotalol dose started with 80mg twice a day and increased to 160mg three times per day, the fetus successfully converted to sinus rhythm without relapse, and the cardiac function was restorted.The maternal QT interval prior and after increases dose were normal.

The sotalol dose was decreased to 160mg twice a day at 27 weeks gestation and further weaned gradually one week prior to delivery because of maternal fatigability and dizziness. She had elective cesarean section at 37 weeks gestation and delivered healthy baby girl in normal sinus rhythm, the mother post delivery she was well however six hr post delivery she developed SVT with HR 200 bpm confirmed and converted to sinus rhythm after two doses of adenosine and maintained on verapamil.

Conclusion

This report suggests that sotalol is a potent anti-arrhythmic agent in the treatment of fetal SVT because of the excellent placental transfer, especially in hydrops fetalis. However, of more concern are the possible pro-arrhythmic effect both in the mother and the fetus still outweighs it is benefits. The possibility of an adverse effect post withdrawal of these medications must be considered.