A woman of 40 weeks' gestation, who was apparently previously healthy, requ
ired emergency caesarean section after a failed vacuum delivery. While unde
r spinal anaesthesia she developed a supraventricular tachycardia of unknow
n origin. Intravenous verapamil resulted in a conversion to sinus rhythm. F
urther investigations confirmed Wolff-Parkinson-White syndrome, for which s
he required ablation therapy. Appropriate methods of cardioversion in this
clinical setting are discussed. (C) 2001 Harcourt Publishers Ltd.