Sotalol in the treatment of fetal dysrhythmias

Background-Fetal tachycardia may cause hydrops fetalis and lead to fetal de ath. No unanimity of opinion exists regarding the optimum treatment. This s tudy evaluates our experience with transplacental sotalol therapy to treat fetal tachycardias in terms of safety and efficacy. Methods and Results-The charts of 21 patients who were treated with sotalol for fetal tachycardia were reviewed. Ten fetuses had atrial flutter (AF), 10 had supraventricular tachycardia (SVT), and I had VT. Hydrops fetalis wa s present in 9 fetuses. Drug treatment was successful in establishing sinus rhythm in 8 of 10 fetuses with AF and in 6 of 10 fetuses with SVT. The mor tality rate in this study was 19% (4 of 21 fetuses 3 had SVT and 1 had AF); 3 deaths occurred just days after the initiation of sotalol therapy, and 1 occurred after a dosage increase. At birth, tachycardia was present in 6 i nfants. Two patients who converted to sinus rhythm in utero suffered from n eurologic pathology postnatally. Conclusions-Fetal tachycardia is a serious condition in which treatment sho uld be initiated, especially in the presence of hydrops fetalis, The high s uccess rate in fetuses with AF suggests that sotalol should be considered a drug of first choice to treat fetal AF, The low conversion rate and the fa ct that 3 of the 4 deaths in this study occurred in fetuses with SVT indica te that the risks of sotalol therapy outweigh the benefits in this group an d that sotalol should, therefore, be limited in the treatment of fetal SVT.