Clinical Value of Calibrated and Differentiated Displacement Apexcardiography in Ischemic Heart Disease

Abstract

The calibrated left apexcardiogram with time constant 4 s and its first derivative (dA/dt) has been evaluated in 62 patients with ischemic heart disease and in 50 normal subjects. The normalized positive peak of dA/dt (max dA/dt/Ad), the peak velocity of contractile element shortening (Vpm), the normalized negative peak of dA/dt (min dA/dt/Ar), and the time constant of myocardial relaxation T as well as the time interval from R wave of the electrocardiogram to the peak positive dA/dt (R-max dA/dt) and the total apexcardiograp-hic relaxation time interval divided to mean arterial pressure (TRI) were measured. In patients with ischemic heart disease we found a decrease of max dA/dt/Ad, Vpm, min dA/dt/Ar and an elongation of T, R-max dA/dt, and TRI, when compared to controls.