A simplified mitral valve method for two-dimensional echo Doppler blood flow calculation: Validation in an open-chest canine model and initial clinical studies

Quantitative two-dimensional Doppler echocardiography is increasingly used for the calculation of cardiac blood volumes. This study evaluates a simplified method for measuring volume flow at the mitral valve orifice. In four open-chest dogs the simplified mitral valve method was compared to a previously described mitral orifice method for Doppler volume flow calculation and to data obtained by electromagnetic flow measurement. Cardiac output varied from 1.4 to 7.7 L/min. Correlation for both the Doppler method and the electromagnetic meter volume flows was r = 0.98 to 0.99, and there was no significant difference between the two methods. In a clinical pilot study, 10 children were studied in the catheterization laboratory, and the simplified Doppler flow method was compared to thermodilution cardiac output measurements with good results. The study indicates that the simplified mitral valve method provides acceptable accuracy for Doppler cardiac output measurement.