Circadian variation in blood pressure: implications for the elderly patient.

In most people, blood pressure (BP) displays a characteristic diurnal pattern, with a decline during sleep and a sharp increase around the time of awakening. The early morning surge in BP is synchronous with an increase in the risk of catastrophic cardiovascular events, including acute myocardial infarction, sudden cardiac death, and stroke. Although most clinical investigations have centered on modulating or even preventing the morning surge, emerging data suggest that it may be important to avoid nocturnal hypotension, especially in elderly patients and in those with established atherosclerotic disease. Considerable evidence has been accumulated to suggest that excessive lowering of BP at night (whether naturally or through the use of antihypertensive medications) can result in untoward ischemic phenomena, including silent cerebral damage (Binswanger's disease) or ophthalmologic symptoms (eg, anterior ischemic optic neuropathy). Controlled-onset extended-release verapamil, through its unique delivery system, tends to diminish the morning BP surge, whereas it preserves a normal nocturnal BP decline; its effect on preventing early morning cardiovascular catastrophes (while preserving relatively normal nocturnal BP) is currently being tested in a large, international clinical trial.