Fetal supraventricular tachycardia diagnosed and treated at 13 weeks of gestation: A case report

Supraventricular tachycardia (SVT) is the most commonly encountered clinically significant tachycardia in the fetus. When SVT is sustained, congestive heart failure and fetal hydrops may ensue, due to both systolic and diastolic dysfunction. Sonographic diagnosis is usually incidental during the second or third trimester. Treatment goals are cardioversion to sinus rhythm and reversal of cardiac dysfunction. We describe a case of fetal SVT diagnosed at 13 weeks of gestation. Treatment with digoxin and flecainide was successful; the heart rate returned to sinus rhythm within one day, and fetal hydrops resolved within 8 days of treatment. We suspect that as more first-trimester examinations are performed, more cases with SVT will be diagnosed. We discuss the treatment protocol, and suggest that co-administration of two drugs that act synergistically may be more efficient than monotherapy, which is currently used as the first line of treatment. In addition, we discuss the potentially deleterious effect of heart failure encountered at an early developmental stage on the central nervous system. More data need to be collected in order to substantiate a clear recommendation regarding optimal management.