Atherosclerosis or hardening of the arteries?
This paper discusses the consequences of the loss of elasticity by the aorta and large arteries in old age. As the heart compresses its own arteries during contraction, much of the myocardium is perfused only during diastole, so that adequate diastolic pressure is a vital necessity for it. Diastolic pressure depends largely on the elasticity of the aorta and large arteries, constituting the arterial reservoir, which stores energy by its distension during systole and returns it to the system during diastole. Loss of elasticity with advancing age means that the arterial reservoir can store less energy and becomes less effective in evening out the pulsating pressure imposed on the system by the left ventricle. Hence, systolic pressure tends to rise and diastolic pressure to drop. Together with other imperfections developing in old age, and combined with atherosclerotic and thrombotic obstructions, circumstances can arise when the arterial reservoir becomes incapable of producing sufficient pressure for the adequate perfusion of some regions of the heart.
Seely
S
S
Department of Cardiology, University of Manchester, Royal Infirmary, U.K.
D003324:Coronary Artery Disease / Q000503:physiopathology*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D009200:Myocardial Contraction