New-onset ventricular tachycardia during pregnancy.

During evaluation for palpitations, presyncope, or syncope, seven pregnant women had documented ventricular tachycardia. Before pregnancy none had a history of significant cardiac disease or symptomatic arrhythmia. The tachycardia rate ranged from 117 to 250 beats/min and lasted up to 65 seconds. Arrhythmia evaluation in five of the patients suggested catecholamine-sensitive ventricular tachycardia. This diagnosis was supported by either a positive relation to exercise or isoproterenol infusion, suppression of arrhythmia by beta-blockade or sleep, and lack of induction of arrhythmia by programmed electrical stimulation of the heart. The arrhythmias resolved in one patient soon after evaluation and in one other patient after 2 months of controlling therapy. Five other patients continued to receive therapy throughout pregnancy. Delivery was accomplished in all patients without significant maternal or neonatal complications.