Ejection phase indexes by invasive and noninvasive methods: an apexcardiographic, echocardiographic and...

A new noninvasive method of measuring ejection fraction and the mean velocity of circumferential fiber shortening from the apexcardiogram and carotid pulse tracing is described and compared with the echocardiographic and angiographic measurement of these values in 35 patients with coronary artery disease. The correlations of the apexcardiographic derived values with the angiographic measurements were excellent (r = 0.89 and 0.96, respectively, P less than 0.001) even though asynergy was present in 14 of the 35 patients. Only 6 percent of the derived ejection fractions and none of the mean velocity measurements were discordant with the angiographic data. In contrast, correlations of the echocardiographic measurements of the ejection phase indexes with the same angiographic data were poorer (r = 0.75 and 0.66, respectively, for ejection fraction and mean velocity, P less than 0.01). Twenty-eight percent of echocardiographic ejection fraction measurements and 20 percent of the echocardiographic mean velocity measurements were discordant with the angiographic data. It is concluded that the apexcardiogram is a dependable bedside test for estimating left ventricular function and is superior to the echocardiogram for measuring ejection phase indexes.