Continuous electrocardiographic monitoring in hypertensive crises in pregnancy. Twenty-four patients first seen with hypertensive crises during pregnancy were studied by continuous electrocardiographic monitoring for a period of 24 hours to detect the presence of serious ventricular arrhythmias. Three patients were excluded from analysis because of low serum potassium levels. Thirteen of the remaining 21 patients had ventricular tachycardia on subsequent analysis of the electrocardiogram. These arrhythmias subsided after induction of anesthesia when blood pressure control was optimal. This finding may be implicated in the pathogenesis of pulmonary edema and sudden death in these patients. 