Malignant ventricular arrhythmias in eclampsia: a comparison of labetalol with dihydralazine.

OBJECTIVE

Our aim was to assess the impact of beta-adrenergic blockade during the peripartum period on the previously observed high incidence of ventricular arrhythmias in eclamptic parturients.

STUDY DESIGN

An open, randomized comparison of intravenous labetalol versus dihydralazine was conducted in 40 eclamptic subjects in the peripartum period. Cardiac rhythm was assessed by blinded analysis of a 24-hour Holter record by means of the Lown classification of arrhythmias.

RESULTS

There was a significantly higher incidence of serious ventricular arrhythmias in patients receiving dihydralazine (81%) than in those receiving labetalol (17%, p < 0.0001). Patients receiving labetalol showed a significant decrease in mean heart rate (p < 0.0001), whereas patients receiving dihydralazine showed a significant increase (p < 0.0001).

CONCLUSION

The introduction of beta-adrenergic blockade into peripartum hypertensive management of eclampsia significantly reduced the incidence of dangerous ventricular arrhythmias. Myocardial oxygen supply/demand ratio may be improved by beta-blockade.