The use of short-term ambulatory blood pressure monitoring in differing forms of hypertension.

Abstract

Single blood pressure readings represent the conventional approach for determining the presence and severity of hypertension. However, the relationship between single (casual) readings and the whole-day blood pressure average is weak, especially in patients with borderline hypertension and in the elderly. In this study we have compared casual blood pressures with the averages of blood pressures obtained during short-term (two-hour) and long-term (24-hour) ambulatory monitoring in patients with mild (n = 19), moderate (n = 11), or predominant systolic (n = 11) essential hypertension. The blood pressure averages obtained during long-term monitoring were significantly lower than the casual blood pressure in all three subgroups. The averages of short-term monitoring in the morning were in between the other two blood pressure levels. The correlation coefficients between two-hour morning averages of pressure and whole-day averages were highly significant (p less than 0.01 or better), and stronger than those between casual and whole-day average pressures, in the group of patients as a whole and in all three subgroups. The slopes of the regression equations were close to unity. Therefore, ambulatory short-term monitoring of blood pressure in the morning is superior to casual blood pressure and probably is an adequate substitute for whole-day observations in quantifying whole-day blood pressure levels in hypertensive patients, especially in patients with mild hypertension and in those with predominant systolic hypertension.