EUROPEAN STUDY ON MATERNAL AND FETAL MANAGEMENT OF FETAL SUPRAVENTRICULAR TACHYARRHYTHMIA - PROPOSED PROTOCOL FOR AN INTERNATIONAL PROJECT

Objectives: This European protocol is designed to estimate the efficac y of transplacental digoxin administered intravenously to the mother i n sustained fetal supraventricular tachyarrhythmias (FSVT) with or wit hout cardiac failure and in intermittent runs of FSVT with cardiac fai lure. The natural history of FSVT is evaluated in self-limited runs of FSVT without cardiac failure. Study structure: The fetal criteria for inclusion in the study are: gestational age <35 weeks, a normal cardi ac anatomy, no severe extracardiac anomalies and a heart rate of the F SVT >200 beats/min. The maternal criteria include no prior treatment w ith digoxin or drugs effecting fetal heart rate and hemodynamics, and no contraindication to digoxin. Doppler fetal echocardiography is util ized for the diagnosis of the type of FSVT, sequential evaluation, and assessment of fetal hemodynamics. Fetuses are assigned two groups: Gr oup I includes all fetuses with sustained FSVT and those with intermit tent runs and cardiac failure; Group II comprises fetuses with intermi ttent runs and no cardiac failure. Fetuses in Group I will be treated, Group II will receive no treatment initially and will be observed. Tr eatment is based on a acute loading phase with digoxin administered in travenously to the mother for a period of 7 days. Doses are adjusted t o through levels of maternal digoxin, maternal clinical condition, and electrocardiogram. Lf sinus rhythm is obtained, a maintenance phase f ollows with oral digoxin. Another drug, according to local experience and preference, is added to oral digoxin if digoxin intravenously fail s to restore sinus rhythm and gestational age is <36 weeks. Post natal outcome will be followed by sequential clinical and Holter examinatio ns. The data collected will be reviewed in a blinded fashion. The coll ection of the data for the protocol requires extensive information on the maternal, fetal, and long-term follow-up studies. They are detaile d in the Appendix section. Expected results: We propose to obstetricia ns and pediatric cardiologists involved in fetal cardiology a rational e for the management and treatment of FSVT. Our expectation is to obta in a controlled study on a large number of cases at an international s cale and thus provide a homogeneous maternal and fetal therapeutic str ategy for FSVT.