Prevalence of Non-Dipping Phenomenon among Hypertensive Coronary artery disease (CAD) Patients

Abstract

The most important and consistent sources of blood pressure variation and the diurnal changes are associated with the sleeping-waking cycle. For these reasons, the blood pressure in any individual subject is not easily determined by clinic blood pressure measurements which can be also called snap-shot blood pressure measurements. Technical progress in measuring 24-h ambulatory blood pressare, has now permitted the measurement of several components of day and night blood pressure variability. It has been known for many years that blood pressure decreases during the night, usually by 10% to 20 %. People could be classified as " dippers " or " non-dippers " according to the degree to which their blood pressure falls during sleep. While the majority of people would be classified as dippers (usually defined as a nocturnal decrease of 10 % or more), there are a variety of clinical situations associated with a diminished nocturnal fall of blood pressure. Non-dipping maybe seen in healthy normotensive individuals, but is more commonly seen in hypertensives. Several cross-sectional studies have shown that target organ damage maybe more pronounced in non-dippers than in dippers. Ambulatory blood pressure monitoring is an important technique for studying normal and disturbed mechanisms controlling circulation in daily life.