No drugs are completely safe in pregnancy, but most are rated category C in pregnancy and if the benefit exceeds the risk, then the medication may be given. Amiodarone and atenolol are two medications that should be avoided in the pregnant patient, especially in the first trimester.
Beta blockers are considered safe in pregnancy but they have been associated with intrauterine growth retardation. Atenolol should never be given, however as it has been associated with fetal hypotonia, neonatal respiratory depression, low birth weight and hypoglycemia.
In pregnant patients with stable monomorphic VT, lidocaine, procainamide, or sotalol are recommended as first line agents.
For patients who require anticoagulation after cardioversion, LMWH is the drug of choice. Warfarin can be used in the second and third trimesters but not in the first trimester or last month of pregnancy. As of now, given the limited research, the new oral anticoagulants should not be used in pregnant patients.