Vascular Stiffness and Increased Pulse Pressure in the Aging Cardiovascular System
Schematic representation of pulse pressure amplification. Pressure tracings from the brachial artery and central aorta are shown, from a young individual with a highly compliant vasculature tree (left) and from an old one with stiff vessels (right). Despite similar brachial blood pressures, central blood pressures vary considerably. In young individuals, (which coincides with systolic blood pressures) marks the outward traveling blood pressure wave, while represents the arrival of the reflected pressure wave in diastole, augmenting diastolic blood pressure, and coronary filling. Pulse pressure augmentation in old, stiff vessels leads to a significant increase in as compared to , as wave reflection occurs earlier and faster, leading to an augmentation in systolic blood pressure. Augmentation index is calculated as the difference between the second () and first () systolic peaks (delta ) as a percentage of pulse pressure (see ).