Treating blood pressure to prevent strokes: The age factor

Figure 1 In a young person the elastic aorta expands during systole and absorbs part of the stroke volume. A: This figure depicts the function of the central aorta of a younger person during systole and diastole. During systole, the elastic aorta with each cardiac stroke volume (top filled arrow) is dilated and functions as a reservoir. As a result, not all stroke volume (SV) is transmitted distally. During diastole the elastic recoil of the aorta expels the remnant original SV to distal arteries and arterioles. This function results in a smooth contour of the arterial pulse wave and a narrow pulse pressure (PP) (bottom); B: In an older person, the aorta has lost most of its elasticity resulting in a reduction of its reservoir or capacitance function, resulting in the expulsion of almost the entire SV to the distal arteries with practically no diastolic blood flow (top filled arrow. This results in a distortion of the arterial pulse wave (bottom), an increase in systolic blood pressure, a decrease in diastolic blood pressure, and a widening of PP. Adapted with permission from Franklin et al[12].