Changes in blood pressure and vascular physiology: Markers for cardiovascular disease

Changes in systolic and diastolic blood pressure are markers of altered vascular physiology and premature cardiovascular disease. Perhaps the most important markers to note are systolic pressure and pulse pressure, both of which are superior to diastolic pressure in predicting cardiovascular morbidity and mortality. They are also surrogates for arteriosclerosis or 'hardening of the arteries.' Arteriosclerosis, which involves excess collagen deposition, is different from atherosis, which involves an inflammatory response to lipid oxidation. Arteriosclerosis plays a major role in the genesis of systolic hypertension and in the sequelae of hypertension. Thus, there is a clinical need for measuring arterial stiffness. It is probable that stiffness of the large vessels is linked to a number of other adverse changes in the distal circulation. Indeed, the degree of arteriosclerosis, which increases with age, leads directly to left ventricular hypertrophy (LVH) because of the phenomenon of wave reflection and central pulse augmentation. Evidence suggests that arteriosclerosis and LVH not only occur in parallel but can be reversed in parallel. Several different methods are being used or developed to measure arterial compliance in clinical practice. These include cuff measurements of systolic blood pressure and pulse pressure, pulse pressure/stroke volume, pulse wave velocity, pulse contour analysis (using either Windkessel computations of proximal and distal compliance or reflectance computations of central augmentation pressure, augmentation index, and the central time-tension index), Doppler ultrasound, and limb plethysmography.