Twenty-four hour ambulatory blood pressure in therapeutically resistant hypertensive patients

Circadian blood pressure and heart rate rhythms were determined in essential and renal hypertensive patients who failed to respond to drug therapy. Indirect ambulatory blood pressure and heart rate recordings were measured in 31 subjects for 24 hours. Essential hypertensive patients exhibit 'white coat hypertension', are normotensive outside the clinic and have a higher awake than sleep blood pressure. Blood pressure and heart rate of renal hypertensive patients do not increase in the presence of a physician and there is no difference between awake and sleep values. In contrast to patients with essential hypertension, the circadian fluctuations of blood pressure were depressed in renal hypertensive patients. We conclude that essential hypertensive patients who appear clinically uncontrolled are in fact well controlled in their domestic environment, whereas renal hypertensive patients are consistently uncontrolled. Ambulatory monitoring may help in differentiating the various types of patient and in the evaluation of antihypertensive therapy.