HEMODYNAMICS IN WHITE COAT HYPERTENSION COMPARED TO AMBULATORY HYPERTENSION AND NORMOTENSION

Hemodynamic alterations associated with the blood pressure response in subjects with white coat hypertension may provide insight into the pa thophysiologic mechanisms of this condition. Systemic arterial hemodyn amics were investigated with a recently validated method based on noni nvasive estimates of aortic root pressure and now in 28 subjects with white coat hypertension (diastolic pressure greater than or equal to 9 0 mm Hg measured by the general practitioner [GP arterial pressure] an d ambulatory daytime pressures < 140/90 mm Hg), in 23 subjects with pr eviously untreated, ambulatory hypertension (GP diastolic pressure gre ater than or equal to 90 and < 115 mm Hg and ambulatory daytime diasto lic pressure greater than or equal to 90 mm Hg), and in 32 normotensiv e subjects. The groups did not differ significantly concerning age, ge nder, body surface area, heart rate, stroke index and cardiac index, b ut total peripheral resistance index was increased and total arterial compliance reduced in the white coat group and the hypertensive group compared to the normotensive group. The subjects in the white coat gro up with a systolic arterial pressure during echocardiography that was > 5 mm Hg higher than the ambulatory daytime systolic pressure (n = 19 ) had increased cardiac index, increased total peripheral resistance, and decreased total arterial compliance compared to the normotensive g roup. The subjects in this group with a hemodynamic pattern characteri zed by a high ratio of cardiac index/peripheral vascular resistance we re significantly younger than the subjects with the opposite pattern. Thus, the blood pressure increase in subjects with white coat hyperten sion is associated with increased cardiac output, increased peripheral vascular resistance, and reduced total arterial compliance, but the h emodynamic pattern may be influenced by age.