Implementation of 24-hour blood pressure control.

More than three decades ago, Millar-Craig et al. (1) described the patterns of the circadian variation of blood pressure (BP). They demonstrated by using continuous intra-arterial monitoring, that BP was highest in the early to mid-morning period and lowest at night, rapidly rising again before awakening. Their fi ndings marked the beginning of an era where 24 h assessment of BP was to become increasingly common. However, it took some 20 years before 24 hour ambulatory BP measurement (ABPM) became an integral part of clinical hypertension diagnosis and management. Today, 24 h ambulatory BP assessment is widely used in hypertension clinics, and a search on “24 hour blood pressure control” on Google results in about 4.500.000 hits in 0.32 sec.