• fetal supraventricular tachycardia;
  • ascites;
  • hydrops

Poster Presentation

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  2. Poster Presentation


We describe the management of a patient at 27-weeks gestation, admitted for fetal supraventricular tachycardia (SVT) and ascites.


Fetal tachycardia was evident at 17-weeks gestation, however the patient did not follow-up with medical recommendations. Fetal SVT was subsequently confirmed by ultrasound, with a fetal heart rate of 235 to 240 along with ascites. She was admitted to our obstetric high-risk unit under the care of our maternal fetal medicine physicians, with a plan for continuous fetal monitoring and digoxin therapy. The patient had an arrhythmia herself upon admission, with no prior history. Her electrocardiogram reflected a sinus arrhythmia. The fetal heart rate was in the 240s until antiarrhythmic administration to the mother. The patient was informed that there was a 20% risk of therapy failure and a 25 to 30% risk of fetal mortality.

Daily electrocardiograms and consults with cardiology, pediatric cardiology, and neonatology were ordered. A 1:1 atrioventricular (A/V) block was confirmed by fetal echocardiogram. Propranolol was added to the digoxin plan. In spite of this, the fetus only converted to sinus rhythm for 4 to 6 beats, 1 to 2 times per minute. The fetus also developed pericardial effusions. Flecainide was added, but consent was also obtained for the possible administration of adenosine via a cordocentesis procedure. The addition of flecainide converted the fetus to normal sinus rhythm, and the ascites resolved. The patient was discharged with a prescription for flecainide and biweekly ultrasounds.

The only readmission for the patient was at 39 weeks, when she was scheduled for an induction of labor. The patient was still taking flecainide and continued this through labor. The fetal heart rate was 110 to 120 on admission, and the patient's vital signs were normal. The patient had a repeat neonatology consult prior to delivery, so she was informed that the newborn would be going to the neonatal intensive care unit following birth for cardiac monitoring. She had an uneventful birth, and the newborn had 9/9 Apgar scores. The newborn had a normal heart rate, but the electrocardiogram result was questionable for A/V block. The newborn had persistent normal sinus rhythm subsequently and was discharged on no medications but did have follow-up appointments with a pediatric cardiologist.


This was a successful multidisciplinary effort that resulted in the delay of birth until term for an infant who had refractory SVT, hydrops, heart block, and pericardial effusions. The morbidity and mortality risks are high with such a combination, so the patient benefited from a team with a wealth of experience.