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Echocardiography is a non invasive technique particularly useful to assess both hemodynamics and left ventricular performances; different methods have been proposed to evaluate echocardiographically the cardiac output. The aim of this work is to suggest a new method (planimetry of the area enclosed by echoes from the mitral valve) stating its advantages and limits and to test three already known methods (cubes method, method of Lalani and Lee, method of Rasmussen and coll.) comparing them to thermodilution. In 24 patients admitted in our Coronary Care Unit for acute myocardial infarction 30 measurements have been performed simultaneously with echocardiography and thermodilution. Statistical analysis (correlation coefficient with the method of the square minimums and Student's 't') of the results has shown that the cubes method is unprecise (P = NS) and unbiased (d = 0.97 +/- 15.46); Lalani-Lee method is unprecise (P = NS) and biased (d = 9.64 +/- 21.36) by a systematic underestimate error concealed by the poor precision; Rasmussen and coll. method is precise (P < 0.01) but biased (d = --3.03 +/- 5.5), the systematic mistake being entirely due to the group of patients with abnormal hemodynamics. Our method is precise (P < 0.01) and unbiased (d = --0.04 +/- 9.62) in patients both with normal and abnormal hemodynamics. Therefore this method offers the following advantages: 1) it is unbiased, even in the presence of abnormal left ventricular performance; 2) it is sufficiently precise, having a correlation coefficient with thermodilution of r = 0.80; 3) it measures directly the amount of flow due to the atrial systole; 4) the measurement is rapid and hardly biased by the reader.

M-mode echocardiography has proved in these last years to be a reliable method for the recognition and evaluation of several cardiac diseases, both congenital and acquired. The following is a case we have examined in which M-mode echocardiography has allowed us to diagnose a Valsalva sinus aneurysm combined with a bicuspid aortic valve causing a valvular steno-insufficiency. We discuss the genesis of an echogram situated in the left ventricular outflow tract. A very similar image had been ascribed in the past to the rupture of an aneurysm into the interventricular septum, which caused a filling of the septum itself in diastole and therefore the echogram described above. On the basis of two-dimensional echocardiography, angiography and the autoptic report we could exclude this hypothesis in our case. We suggest that the image might be due to a prolapse of the valvular leaflet in the left ventricular outflow tract and/or to the prolapse of the aneurysm itself in the tract between the valvular leaflet and the interventricular septum.