Supraventricular arrhythmias
Patients with structurally normal hearts may develop supraventricular re-entrant tachycardias
(SVT) due to accessory pathways. Atrial flutter or fibrillation, however, usually indicates underlying
structural heart disease. As arrhythmias are likely to become more troublesome during pregnancy,
patients with known pre-existing paroxysmal atrial arrhythmias should be considered for catheter
ablation prior to pregnancy. Acute episodes during pregnancy may be terminated using vagal manoeuvres,
intravenous adenosine or metoprolol. Direct current cardioversion (DCCV) is safe in pregnancy,
and it should be performed if these measures are unsuccessful or if there is pre-excitation on the
ECG. DCCV should be performed with the patient wedged onto the left side, and a rapid sequence
induction anaesthetic technique should be used if the patient is beyond 20 weeks of gestation to reduce
the risks from aspiration