RESUMEN
OBJECTIVE: To review the diagnosis, treatment, and perinatal outcome of fetal tachyarrhythmias. METHODS: We reviewed the medical records of pregnant women diagnosed with fetal tachyarrhythmia at Asan Medical Center from June 1997 to December 2004. Tachyarrhythmias were classified as either supraventricular tachycardia (SVT) or atrial flutter (AF), and the intrauterine management and long-term outcomes of the infants were analyzed. RESULTS: There were three cases of SVT and four cases of AF. Fetal hydrops was noted in 4 of 7 fetuses and there were no cardiac anomalies. All of them were treated in utero with antiarrhythmic agents including digoxin and flecainide. During antiarrhythmic therapy, sinus rhythm was achieved in 100% of them and the survival rate was 100%. Two infants diagnosed prenatally with SVT developed Wolff-Parkinson-White syndrome after birth. One of them developed paroxysmal SVT but after adenosine treatment she needed no treatment. One fetus with AF was diagnosed with an atrial ectopic tachyarrhythmia postnatally which needed medication for one year and resulted in normal sinus rhythm. At the time of this study, all of them showed normal development without neurological morbidity. CONCLUSION: Fetal tachyarrhythmias diagnosed prenatally can be effectively treated with antiarrhythmic drugs in utero or postnatally even if they had hydropic feature. So they must be referred to a tertiary care center for appropriate counseling and management. We recommend that every SVT or AF should be treated in utero regardless of the presence of hydrops.