Noncircumferential myofiber function: impact on early diastolic filling in children.
Circumferential and noncircumferential myofiber contraction may have varying impact on systolic and diastolic function. The purpose of this study was to determine the relation of circumferential, longitudinal, and oblique fiber shortening to early diastolic filling in children. Twenty-five patients (8.1 +/- 5.6 years of age; 12 boys and 13 girls) with normal echocardiograms and no heart disease had prospective echocardiographic evaluation of circumferential (shortening fraction, fractional area change), longitudinal (left ventricular axial shortening), combined circumferential and longitudinal (left ventricular ejection fraction), oblique (left ventricular systolic twist [LVST]) shortening, and early diastolic filling. Mean LVST was 16 +/- 8 degrees. There was no relation between early diastolic filling indexes and indexes of circumferential or longitudinal shortening. However, there was a significant inverse relation between heart rate-corrected E-wave acceleration time and LVST (r = 0.63, P <.001). Oblique fiber shortening affects early diastolic filling in children. Describing the functional role of noncircumferential left ventricular myofibers may improve our understanding of global left ventricular function.
Michelfelder
E C
EC
Noninvasive Cardiac Imaging and Hemodynamic Research Laboratory, Division of Cardiology, Children's Hospital Medical Center, 3333 Burnet Ave., OSB-4, Cincinnati, OH 45229, USA. miche0@chmcc.org
Khoury
P
P
Witt
S A
SA
Glascock
B J
BJ
Kimball
T R
TR
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003971:Diastole; D004452:Echocardiography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D009200:Myocardial Contraction; D015588:Observer Variation; D012044:Regression Analysis; D015203:Reproducibility of Results; D016276:Ventricular Function