Windkessel effect

Windkessel effect is the term used in medicine to describe the recoiling effect of large arteries (Windkessel vessels). Windkessel in German means ''elastic reservoir. '' Large arteries (eg. aorta, common carotid, subclavian, and pulmonary arteries and their larger branches) contain plenty of elastic and collagen fibers in their walls, which are responsible for their compliance. The pulsatile ejection of the heart is converted into a steady flow of blood in the arteries due to this compliance or elastic recoil (Windkessel effect). When blood is pumped into the them, they expand temporarily to accommodate the excess blood. When the heart enters diastole, the arteries recoil, propelling the blood forward. The windkessel effect also prevents excess rise of pressure during systole and maintains pressure during diastole. Steady flow is necessary for maximum perfusion between blood and tissues in the capillaries. In old age, this effect is lost to an extent due to hardening of vessel walls (arteriosclerosis/atherosclerosis). Thus, there is excess rise of pressure in large arteries during systole (systolic hypertension) and decreased diastolic blood pressure because the extra blood leaves rapidly, resulting in increased pulse pressure (difference between SBP and DBP) and defective perfusion at the periphery.