The Hemodynamic Basis of Atherosclerosis

Abstract

The laws of fluid mechanics apply to the natural conditions in the circulatory system as they apply to any hydraulic system. The effect of the laws of fluid dynamics is considered the primary factor in the development of atherosclerosis because it alone can account for the localization and progressive development of atherosclerotic lesions at specific areas of predilection characterized by curvature, branching, external attachment, or tapering. While such vascular configurations occur in many variations of geometry or anatomical pattern with corresponding variations in patterns of blood flow, their common feature is the production of localized segmental zones of diminished lateral pressure. The diminished lateral pressure or suction effect which occurs in some phase of pulsatile flow in the cardiac cycle is the initial stimulus which produces intimal proliferation as the first change in the progressive development of atherosclerosis. Atherosclerosis may therefore be considered the reactive biological response of blood vessels to the effect of the laws of fluid mechanics at sites of predilection determined by local hydraulic conditions in the circulatory system.