[Functional evaluation of the left ventricle using 2-dimensional and color-coded Doppler echocardiography]

A new parameter for the evaluation of left ventricular function based on color-coded Doppler echocardiography is described. From an apical transducer position the maximal diastolic inflow area across the mitral valve into the left ventricle is registered. A ratio of this area to the left ventricular area in the same plane and frame is calculated. These parameters are evaluated in 17 normal controls and 31 patients with dilatative cardiomyopathy. Additionally, the left ventricular volumes and the ejection fraction are calculated from two-dimensional echocardiography using a disc method. The maximal inflow area is correlated with the stroke volume (r = 0.69, y = 7.0 + 8.6x) and the ratio to the ejection fraction (r = 0.99, y = 0.65 + 0.98 x). The intraobserver-correlation for the maximal diastolic inflow area was r = 0.95, y = 5.5 + 0.79 x and the interobserver-correlation r = 0.89, y = 7.7 + 0.8 x. Finally, the gain dependency of the maximal diastolic inflow area was tested. By increasing the gain at low levels a steep linear increase was noted; at higher gain levels a plateau phase was observed where measurements could be performed.