Physical Considerations on Bernoulli's Law for Mitral Valve Regurgitation

The simplified Bernoulli's equation is widely used in cardiology to measure the pressure difference between the left ventricle (LV) and the left atrium (LA). Even though this is a standard method, its derivation has not been well-clarified physically, which may lead to inappropriate usage of the method. In this study, derivation of the simplified Bernoulli's equation is presented with five assumptions: incompressible, irrotational, steady-state, negligible LV-LA height difference, and LA open space. Each assumption is analytically and numerically discussed as quantitatively as possible. We found that three factors, the LA size, the measurement location of regurgitation velocity, and the patient position in measuring regurgitation, need to be considered for appropriate usage of the simplified Bernoulli's equation. (C) 2010 The Japan Society of Applied Physics