Twenty-four-hour blood pressure control

Abstract

The increasing availability of ambulatory blood pressure monitoring has shifted interest in blood pressure measurement from the doctor's office to the entire 24-h period. Routine office blood pressure recordings correlate poorly with left ventricular mass, a sign of early target-organ damage. In contrast, ambulatory blood pressure or estimates of 24-h blood pressure load show a good correlation with left ventricular mass. Circadian blood pressure rhythms may be important in determining future cardiovascular events. For example, patients who maintain high nocturnal blood pressures (non-dippers) experience more cardiovascular sequelae than do nocturnal dippers, with women non-dippers having the greatest risk. Longer-acting antihypertensive drugs may return circadian blood pressure rhythms to normal by converting non-dippers to dippers. Adequate control of blood pressure toward the end of each 24-h cycle may reduce the early morning rise in cardiovascular events associated with awakening and ambulation. Recent improvements in the estimation of trough to peak ratio have provided a useful arithmetic index for comparing the antihypertensive effects of different compounds over 24-h dosing intervals. Long-acting agents have now been identified in each of the major classes of antihypertensive drugs, making it now possible to maximize target-organ protection by achieving good 24-h blood pressure control in most hypertensive patients.