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 Hotter 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.