[A comparison between mitral and aortic outputs evaluated by Doppler echocardiography in a group of healthy subjects:...

Doppler echocardiography is a potentially useful tool for the non invasive evaluation of cardiac output and, therefore, for the quantitative assessment of valvular regurgitation. The aim of our study was to establish the presence of possible pitfalls in the evaluation of mitral and aortic regurgitant fraction obtained by Doppler echocardiography comparing the cardiac output measured at the level of the mitral and aortic valve. For this purpose 19 healthy volunteers, aged between 14-68 years, were studied. Stroke volume and cardiac output were calculated at the level of the mitral and aortic valve. The methods we used for the measurement of both the mitral and aortic cardiac output had already been validated and presumes that the shape of the valve annulus, is circular. No statistically significant differences were found between the parameters obtained at the two different valvular levels. Furthermore, cardiac output values correlated fairly well (r = 0.83, ESS = 0.78 l/min). In 9 subjects the aortic cardiac output was greater than the mitral one, while in the others mitral cardiac output was greater. The average of the differences between the two cardiac outputs was 0.58 +/- 0.48 l/min with a regurgitation fraction of 9.5 +/- 7.9%. Our results show that the mitral and aortic stroke volume and cardiac output, as measured by Doppler echocardiography (considering a circular shaped valve annulus, are not statistically different and correlate fairly well in our normal subjects. Nevertheless, we observed a certain degree of variability between the mitral and the aortic cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)