Characterization of left ventricular external wall motion in man by video dimension analyzer (Vidian).

Abstract

Several investigators have described close relationships between left ventricular wall motion and physiologic cardiac events. Using an improved wall motion tracking devide (Vidian) in studies of 30 patients, we have compared the dynamics of left ventricular wall motion, recorded noninvasively, with high fidelity left ventricular and aortic pressures, intracardiac phonocardiograms, apexcardiograms, and cyclic left ventricular volume curves obtained during cardiac catheterization. Wall motion tracking signals comprised: pre-ejection outward deflection commencing with the first component of the first heart sound and coincident with the pre-ejection phase of the left ventricular pressure and apexcardiogram; a sharp descent during ejection, commencing with the "E" point of the apexcardiogram and with the onset of the upstroke of the aortic pressure; end ejection nadir, synchronous with the dicrotic notch of the aortic pressure; a nadir representing cessation of inward displacement, presumably reflecting slight inertial motion of the wall; a brief period of isovolumic relaxation which terminated synchronously with the "O" point of the apexcardiogram; rapid, then slow filling waves, coincident with those of the apexcardiogram, and demarcated by a transitional angulation synchronous with the third heart sound; and "a" wave, occurring simultaneously with that of the apexcardiogram. Ventricular wall motion tracking signals also corresponded to curves representing cyclic changes in left ventricular minor radius, and chamber volume derived from cineventriculograms. In 10 patients with abnormal contraction patterns detected by biplane cineventriculography, anomalous deflections were also recorded during ejection by the Vidian. Left ventricular wall motion tracking with the Vidian: 1) provides a sensitive index for timing of intracardiac events, 2) reflects cyclic changes in ventricular volumes and minor dimensions, 3) provides a convenient noninvasive technique for detection of regional asynergy involving the lateral left ventricular wall, and 4) by correlation with simultaneous ventricular pressure measurements, may provide useful information regarding left ventricular pressure/segment dimension relations.