To elucidate whether the mode of left ventricular opacification using sonicated serum albumin (SSA) is dependent upon the severity of left ventricular dysfunction, SSA was administered intravenously to 26 patients with dilated cardiomyopathy, 24 patients with anteroseptal myocardial infarction, and 9 normal control subjects. The left ventricular inflow pattern in echocardiograms on the apical 4-chamber view was classified into 2 types: straight or whirling. The ratio of left ventricular opacified area to left ventricular end-diastolic area, called the percent left ventricular effective fraction (%LVEF), was also calculated. The inflow pattern was straight in all normal control subjects and 9 myocardial infarction patients, whereas 15 myocardial infarction and all dilated cardiomyopathy patients showed the whirling pattern. Percent LVEF was significantly smaller in patients with dilated cardiomyopathy (45 +/- 22%, p < 0.0001) and myocardial infarction (65 +/- 14%, p < 0.001) than in normal control subjects (84 +/- 7%). The area that was not opacified was observed only in the infarcted area in cases of myocardial infarction, and over wide regions in cases of dilated cardiomyopathy. In addition, there were significant correlations between %LVEF and ejection fraction or peak filling rate. These findings indicate that contrast echocardiography using SSA can reflect sensitively the severity of left ventricular dysfunctions and detect the regions involved in patients with dilated cardiomyopathy and myocardial infarction.