[Reproducibility of the Doppler spectrum of the left ventricular stroke volume].

The left ventricular stroke volume was determined in 15 healthy male volunteers of the same age (21-23 yrs). The systolic function was characterized by six, the diastolic function by five parameters. The diameter and the cross-sectional areas of the outflow tract were determined. Intraobserver, interobserver and day-to-day variability of these parameters were investigated. The reproducibility was tested by 4 statistical methods. The significance of the differences between the mean values was determined, as well as the percentual difference of the mean values and of the variation coefficients. Linear regression analysis was done and the correlation coefficient was determined for each parameter. The variation coefficient could be regarded as the best statistical method for characterizing the reproducibility. Thus the simplest, directly measured Doppler parameters gave the best reproducibility. The reproducibility of the complex, calculated parameters was poorer. Comparing the intra- and interobserver reproducibility error, the former one was less.