[Long-term ambulatory blood pressure monitoring: what is normal?]

Various parameters can be evaluated in ambulatory blood pressure monitoring: mean values, percentages of elevated readings, highest and lowest single values, variability, and rhythm. In most parameters only distributions (mean, standard deviation, percentiles) of the results were investigated in selected (usually normotensive or hypertensive) samples. Attempts to define limits of normalcy were predominantly focused on mean values. For the mean values during daytime the equivalent levels of office blood-pressure readings were now defined. This provides evaluation of ambulatory blood pressure monitoring in terms of the established office blood-pressure scale. For mean daytime values, the limits of normalcy (corresponding to 140/90 mmHg office-BP) are about 135/85 mmHg. Clearly, hypertensive mean values (corresponding to 160/95 mmHg office BP) are 146/87 mmHg. These limits of blood pressure mean values during daytime may be considered for therapeutic decisions.