ACOUSTIC QUANTIFICATION OF LEFT-VENTRICUL AR VOLUMES AND EJECTION FRACTION IN MYOCARDIAL-INFARCTION - COMPARISON WITH ECHOCARDIOGRAPHIC, ANGIOGRAPHIC AND ISOTOPIC DATA

The object of this study was to assess the reliability of measurements of left ventricular volumes and ejection fraction by acoustic quantif ication by the method of summation of discs in acute myocardial infarc tion. Thirty-two patients with an average age of 55.9 +/- 12 years wer e studied prospectively on average 6 +/- 2 days after the onset of myo cardial infarction. Within 48 hours, the patients underwent TM echocar diography (Teichholz's method) two-dimensional echocardiography (Simps on's method on freeze frames and acoustic quantification) before left ventricular angiography and isotopic ventriculography, considered as t he reference methods for comparing left ventricular volumes and ejecti on fractions. The data displayed in real time by acoustic quantificati on correlated well with the results of left ventricular angiography (r = 0.77: p = 0.0001) and moderately underestimated (+4.1 +/- 11.9%) th e ejection fraction, but were relatively disappointing for estimating volumes. When compared with isotopic ejection fraction, the correlatio n coefficient was r = 0.71 (p = 0.0004) and the values were overestima ted. In this study, acoustic quantification was the most reliable echo cardiographic method of assessing the left ventricular ejection fracti on with reference to contrast angiography (Teichholz : r = 0.56; p = 0 .0014: Simpson : r = 0.76; p = 0.001). The authors conclude that asses sing the left ventricular ejection fraction with acoustic quantificati on is reliable in acute myocardial infarction. However, the method is not very accurate in measuring end systolic and end diastolic volumes.