Quantitation of Valvular Regurgitation from Multiple Indicator-Dilution Curves

Evaluation of aortic and mitral valve regurgitation by radionuclide ventriculography: comparison with the method of Sandler and Dodge

The present investigation was undertaken to introduce a quantitative scintigraphic method for evaluation of regurgitation and to compare it with the generally accepted quantitative method of Sandler and Dodge (Sandler et al., 1963). Radionuclide ventriculography was carried out after injection of 20 mCi 99mtechnetium-labeled red blood cells. Time-activity curves were obtained from the left and right ventricular regions. The ratio (A) of end-diastolic-end-systolic count-rate differences for the left and right ventricles was calculated. The ratio (A) was compared with a hemodynamic ratio (Ah) determined after the method of Sandler and Dodge (1963) with the stroke volume of the left ventricle measured angiographically, and the stroke volume of the right ventricle measured by thermodilution. In 33 patients with aortic and mitral valve regurgitation we found a correlation of r = 0.75 between (A) and Ah). Due to a broad range of normal values of (A) the sensitivity of the scintigraphic method is low. The specificity seems to be high, however, since in 64 patients with all types of heart diseases there were no false positive results. Comparing the described scintigraphic method with other modern or generally accepted methods, the principal advantages are noninvasiveness, good practicability, and the fact that important additional information about the functional state of the heart is gained. This is important in follow-up studies in patients with chronic valvular incompetence. It seems that this method will become a valuable supplement to heart catheterization in the diagnosis of valvular heart disease and may partially replace invasive methods for measuring the regurgitation fraction.

Effects of Aortic Insufficiency on Circulatory Dynamics of the Dog

In dogs with chronic aortic insufficiency accompanied by cardiac hypertrophy, the coronary blood flow, cardiac oxygen consumption, coronary arteriovenous oxygen difference, coronary oxygen utilization, systolic pressure and cardiac rate are increased significantly above the normals, while coronary venous oxygen saturation, coronary resistance and diastolic pressure are significantly decreased.