The ascending slope of the apexcardiogram. Its relationship with angiographic determination of left ventricular function.

The relationship between the ascending slope of the apexcardiogram (ACG) and direct determination of left ventricular (LV) performance as assessed angiographically by measurement of the ejection fraction (EF), mean velocity of circumferential fiber shortening (mVcF), mean normalized systolic ejection rate (MNSER), and percentage of the systolic shortening of ventricular long axis (%L), were studied in 40 patients with a wide variety of cardiac diseases. The ascending slope correlated closely and significantly (P less than 0.05) with all of them: (1) EF (r = 0.774), (2) mVcF (r = 0.776), (3) MNSER (r = 0.767) and (4) %L (r = 0.668). In a control group of 10 normal subjects, phi was determined and compared with that obtained in patients with depressed LV function, the difference being statistically significant (P less than 0.01). Other noninvasive indices derived from simultaneous phono-mechano-cardiographic readings were also studied. The calibrated ACG did not correlate with any of the hemodynamic indices; however the calibrated carotidogram did correlate with the peak systolic aortic pressure (r = 0.503). The ratio preejection period/left ventricular ejection time correlated significantly, but less than previously reported with the EF (r = 0.574). We conclude that the value of phi leads to additional evidence supporting the use of quantitative ACG as a noninvasive measure of LV performance in patients with cardiac disease.