Evaluation of left ventricular function by apex cardiography. Comparison of "t(dA/dt)/A" with hemodynamic indexes and with myocardial perfusion scintigraphy.

Left apex cardiograms (ACGs) were recorded in a total of 112 subjects; 32 normal individuals, 36 patients with ischemic heart disease, 19 patients with idiopathic cardiomyopathy and 25 patients with other cardiovascular diseases. The apex cardiographic index t(dA/dt)/A showed a good, positive correlation with t(dp/dt)/p (r = 0.81), p < 0.001) and also a positive correlation with Vmax (r = 0.76) as well as with ejection fraction (r = 0.65). It was weakly correlated with cardiac index and LV max dp/dt (r = 0.60 and r = 0.57, respectively) and had inverse correlations with LV end-diastolic pressure (r = -0.40) and LV end-diastolic volume (r = -0.59). There was no significant correlation between t(dA/dt)/A and LV peak systolic pressure. The t(dA/dt)/A value was significantly lower in the congestive cardiomyopathy group than in any other group investigated: ischemic heart disease, hypertrophic cardiomyopathy, occlusive thromboaortopathy or atrial septal defect (p < 0.001). Of the patients with ischemic heart disease examined by thallium-201 myocardial scintigraphy, those with imaging defects displayed significantly lower values for t(dA/dt)/A than those without imaging defects (p < 0.001), and the index tended to be lower in the patients with moderate to large imaging defects than in those with small defects. The results of the present study indicate potential usefulness of the ACG index of t(dA/dt)/A in noninvasive evaluation of the LV function and presumably of the mode of myocardial contraction.