Influence of maturation on diastolic events of left ventricle in children.
To delineate the influence of maturation process on diastolic events of cardiac cycle, we had performed M-mode and Doppler echocardiography in 120 normal subjects aged from 1 hour to 16 years. The isovolumic relaxation period (IVRP, msec), defined as the time interval between the aortic valve closure to the mitral valve opening, was not statistically different in various age groups. Different equations based on individual ranges of cycle length (CL) were disclosed for each of three different age groups, demonstrating a positive linear correlation between IVRP and CL. On the contrary, an equation showing a linear correlation between diastolic total period (DTP, msec) and CL could be applied to all age groups: DTP = 0.58 x CL-75.2 (r = 0.89, p less than 0.001). Similarly applicable to all age groups, the duration of early diastolic filling (D-F, msec) changed with DTP in all age groups by an equation: D-F = 0.57 x DTP + 0.11 (r = 0.93, p less than 0.001). Ratios between the maximal velocity of early (E) and atrial (A) diastolic filling increased gradually with age. This was largely due to an increase in E with maturation, suggesting a depressed early diastolic filling in the young hearts. We conclude that the patterns of diastolic relaxation and filling are heterogeneously affected by the degree of maturation and represent the net results of complex interactions between changing inactivation properties and loading status at various stages.
Wu
M H
MH
Department of Pediatrics, National Taiwan University Hospital, Taipei, R.O.C.
Wu
J M
JM
Chien
S C
SC
Lue
H C
HC
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003971:Diastole / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016277:Ventricular Function, Left