A 38-year-old woman presents 34 weeks pregnant to the ED in atrial fibrillation. Blood pressure is 110/62 mmHg. Echocardiograpy and blood test results are normal.
Which of the following is not a good first line of action?
A. IV amiodaroneAtrial fibrillation is uncommon in pregnancy. Management needs to focus on treating the arrhythmia and protection from thromboembolic events. Pregnancy is a hypercoagulable state, so full anticoagulation with low molecular weight heparin is recommended until 4 weeks after the restoration of sinus rhythm. If the patient is in AF for a short time this is not required, as with non-pregnant patients. DC cardioversion is safe, but is not recommended unless the patient is compromised. The fetus should be monitored with CTG if this is required. Many antiarrhthymics are relatively safe in pregnancy. Flecainide is FDA Category C (it is effective in medically cardioverting patients in AF and is often used to treat fetal arrhythmias). Beta-blockers can also be used (see Question 5). Digoxin is also Category C and is sometimes used for fetal treatment. The dose may need to be increased in pregnancy because of the increased glomerular filtration rate. Levels need to be checked in case of toxicity, which is dangerous for the fetus. Amiodarone is not safe in pregnancy (Category D). It causes fetal thyroid problems and intra-uterine growth retardation, and is teratogenic.