24 H BLOOD-PRESSURE PROFILE AFFECTS THE LEFT-VENTRICLE INDEPENDENTLY OF THE PRESSURE LEVEL - A STUDY IN UNTREATED ESSENTIAL-HYPERTENSION DIAGNOSED BY OFFICE BLOOD-PRESSURE READINGS

This work examines whether the 24 h blood pressure (BP) pattern per se might affect the left ventricular structure independently of the pres sure level. One hundred subjects with abnormally high office BP readin gs who had never received any antihypertensive treatment were submitte d to 24 h ambulatory BP monitoring and left ventricular echocardiograp hic assessment. They were classified into two groups, as follows: dipp ers (group 1), consisting of 46 subjects whose mean nighttime systolic BP was reduced by at least 10% in comparison to the corresponding day time value, and nondippers (group 2), consisting of 54 subjects whose nighttime BP did not drop or was reduced by < 10%. Left ventricular ma ss and end-diastolic volume values, both normalized for body surface a rea, were significantly higher in nondippers (r = 3.12, P < .003, and r = 7.46, P < .001, respectively). The two groups did not differ in di astolic thickness of either intraventricular septum or left ventricula r posterior wall (both values normalized for body surface area), in me an 24 h systolic or diastolic or average blood pressure, or in age. In conclusion, in untreated essential hypertension diagnosed on the basi s of abnormal office BP readings, the higher incidence of left ventric ular mass increase in subjects unable to reduce their blood pressure d uring the night was more due to left ventricular dilatation than to my ocardial wall thickening. The effect of the 24 h BP profile on left ve ntricular volume appears to be independent of both the BP level and ag e. (C) 1997 American Journal of Hypertension, Ltd.