General Principles

Abstract

Echocardiography is an important tool in evaluating cardiovascular hemodynamics. There are multiple benefits for utilizing echo for hemodynamics assessment, which include the noninvasive nature of the examination with no known risks, the portable nature of the examination—can be performed at bedside and repeated as needed, and the complementary information that may be obtained and can help in the comprehensive assessment of the hemodynamic status (e.g., chamber size and function, presence of valve disease, and more). Important principles underlying hemodynamic assessment by echocardiography include the Doppler Principle, Bernoulli Principle, and understanding normal intracardiac pressures, flows, and resistance. The Doppler Principle allows the calculation of blood flow velocity by measuring the Doppler shift of a returning signal that encountered a moving target. Blood flow velocity can in turn be used to calculate intracardiac pressure gradients. Understanding relationships between the various intracardiac pressures can help reach conclusions regarding the hemodynamic status.