ANALYSIS OF THE TEMPORAL SEQUENCE OF LEFT VENTRICULAR SYSTOLE IN NORMAL CHILDREN BY ECHOCARDIOGRAPHY

Abstract

Little data are available regarding measurements of the active state of left ventricular (LV) segmental contraction. Thus we performed echograms (E) in 40 normal school children, to establish and relate normal values for the period of LV systole, as assessed by a variety of E parameters. Duration of contraction of posterior LV wall (LVWSF) and Septum (SSP) was measured from the onset of movement to the point of maximal systolic anterior or posterior excursion respectively. Mitral valve coaptation (MSP) was computed as the duration between closure and opening of the mitral leaflets, as was aortic ejection period (ASP) from seperation to reclosure of the aortic leaflets. Systolic periods measured in milliseconds were: (mean and standard error of mean) LVWSP 281.1 ± 2.8, SSP 261.7 ± 2.6, MSP 316.3 ± 4.4 and ASP 269.5 ± 3.2. Further maximal excursion and systolic thickening of S and LVU were simultaneous. A marked difference between MSP and ASP (48.9±3.5, p <0.001) represented isovolumic LV contraction and relaxation. Thus E may be utilized to analyze isovolumic LV systole. It appears that S systolic excursion may be completed and LVW systolic motion may continue after aortic ejection finishes. The difference between S and LVW systolic period suggests that the active state of contraction of LVW is greater than that of S, and is more important to LV contraction in normal children. (Sponsor: Eli Gold)