Arch Gynecol Obstet (2008) 278:85–88 DOI 10.1007/s00404-007-0516-0 123 CASE REPORT Fetus with heart failure due to congenital atrioventricular block treated by maternally administered ritodrine Shigeki Matsubara · Yukako Morimatsu · Hirohiko Shiraishi · Tomoyuki Kuwata · Akihide Ohkuchi · Akio Izumi · Satoru Takeda · Mitsuaki Suzuki Received: 6 September 2007 / Accepted: 6 November 2007 / Published online: 8 December 2007  Springer-Verlag 2007 Abstract Background The eYcacy of maternal administration of ritodrine in cases of congenital atrioventricular block (CAVB), especially with fetal heart failure, is not yet deter- mined. Case At 21 2/7 weeks of gestation, isolated CAVB with a ventricular/atrial rate of 55–70/130–140 bpm was found in a fetus from a 30-year-old Japanese nulliparous woman with anti-SSA antibody. Cardiothoracic area ratio (CTAR) was 40% and no fetal hydrops was observed. At 30 2/7 weeks, the ventricular rate decreased to 49 bpm with an atrial rate of 125 bpm. CTAR increased to 53.8% and asci- tes appeared. Maternal continuous ritodrine infusion was started with rapid improvement of fetal cardiac function; increment in the ventricular rate to 57 bpm and atrial rate to 137 bpm, with a decrement in CTAR to 44.6%. Ascites also gradually decreased and by the fourth day, it had com- pletely disappeared with CTAR of 40.2%. On the 12th day after ritodrine treatment (32 1/7), amniotic Xuid volume decreased and fetal weight gain stopped, which led us to assume a worsening intrauterine environment, and cesarean section was performed. A 1,178 g male infant was born with a 5-min Apgar score of 8. Continuous isoproterenol infusion was started, increasing the ventricular rate from 71 to 80 bpm. Pacemaker implantation is under consideration to treat this infant. Conclusion Maternal administration of ritodrine not only increased the fetal heart rate but also ameliorated the signs of fetal heart failure, and thus is considered one treatment of choice in CAVB. Keywords Complete atrioventricular block · Heart failure · Ritodrine · Ventricular rate Introduction Congenital atrioventricular block (CAVB) without heart deformity, namely, isolated CAVB, is a life-threatening disorder of fetuses/infants [1, 2]. Maternal autoantibodies, such as SSA or SSB antibodies, are well known causes of CAVB [1, 2, 4]. A variety of treatment strategies have been proposed, such as early delivery with infant heart pacing, in utero fetal heart pacing, maternal glucocorticoid adminis- tration, etc. [1, 5, 8]. Maternal administration of beta-sym- pathomimetic drugs has also been employed by some clinicians [1, 5, 8], but its eVectiveness is not yet com- pletely determined [1, 5, 8]. Hydrops fetalis, a sign of fetal heart failure, signiWcantly raises fetal/infantile mortality in CAVB cases [1, 10]. Although one previous report sug- gested the limited eYcacy of sympathomimetics in CABV with hydrops [7], data are lacking. Previously, our team described the Wrst case report in which maternal administration of ritodrine, a representative sympathomimetic drug, increased the heart rate in a fetus with CAVB [6]. Another similar case report appeared later [9]; however, these two reports only dealt with fetuses S. Matsubara (&) · Y. Morimatsu · T. Kuwata · A. Ohkuchi · A. Izumi · M. Suzuki Department of Obstetrics and Gynecology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan e-mail: matsushi@jichi.ac.jp H. Shiraishi Department of Pediatrics, Jichi Medical University, Tochigi, Japan S. Takeda Department of Obstetrics and Gynecology, Juntendo University, School of Medicine, Tokyo, Japan