13 weeks' gestation • heart palpitations • chest tightness • Dx?
► Heart palpitations
► Chest tightness
Acute episodes of SVT that are refractory to vagal maneuvers or occur despite medical management can be treated acutely in pregnancy with adenosine, which effectively stops episodes about 90% of the time.2 (See the TABLE8,9 for a list of antiarrhythmics that may be used to treat AVNRT.)
Catheter ablation is first-line treatment for AVNRT in nonpregnant patients.1,5 The risks of undergoing ablation during pregnancy include fetal exposure to radiation and anesthetic drugs.2,3 Therefore, this treatment should be used only when pharmacologic treatment is unsuccessful and risks to the mother and fetus due to the arrhythmia outweigh the risks of the procedure. Ablation can be offered postpartum as more definitive therapy.
Our patient was started on metoprolol tartrate 12.5 mg bid at 35 weeks’ gestation due to increasingly common and persistent palpitations. This helped control the episodes for 2 weeks, at which point they increased again in frequency. These were terminated using Valsalva maneuvers; increasing the metoprolol dosage was prohibitive due to patient intolerance.
Following an uncomplicated delivery, and discontinuation of metoprolol, the patient reported a decrease in both the number of episodes and the duration of SVT. Ultimately, she opted for a catheter ablation to prevent SVT exacerbation during subsequent pregnancies.
THE TAKEAWAY
AVNRT (and other tachyarrhythmias) may worsen or manifest with physiologic changes that occur during pregnancy. After establishing the diagnosis, effort should be made to manage the condition conservatively with Valsalva maneuvers and medication. Catheter ablation should be offered postpartum as a more definitive treatment option.
CORRESPONDENCE
Joseph Lane Wilson, MD, ECU Brody School of Medicine, Department of Family Medicine Medical Director, 101 Heart Drive, Greenville, NC 27834; wilsonjo@ecu.edu.
