Antihypertensive therapy in pregnancy directed by noninvasive hemodynamic monitoring.

Invasive and noninvasive investigations suggest that the hemodynamics of pregnant hypertensive patients are heterogeneous. Nineteen pregnant patients were evaluated before changes in antihypertensive therapy. Cardiac output was measured by Doppler technique. Blood pressure was measured by automated cuff. Systemic vascular resistance was calculated. Two distinct groups were identified on the basis of differences in cardiac output (p less than 0.0001) and systemic vascular resistance (p less than 0.0001). Those with high resistances were treated with hydralazine. A modest antihypertensive effect was achieved (-6.9 mmHg, p = 0.01), but systemic vascular resistance was dramatically reduced, (-534 dyne.sec.cm-5, p less than 0.0001) and was associated with a compensatory increase in cardiac output (2.0 liters/min, p less than 0.0001). Those with a high cardiac output were treated with atenolol. An antihypertensive effect was achieved, (-17.0 mm Hg, p = 0.008), which was associated with a reduction in cardiac output (-2.8 liters/min, p less than 0.0001).