title: Doppler flow parameters of left ventricular filling in infants: how long does it take for the maturation of the diastolic function in a normal left ventricle to occur?
abstract: OBJECTIVE
  To study the impact of the maturational process of diastolic left ventricular function on trans-mitral Doppler flow parameters.
  
  
  METHODS
  In a survey we examined pulsed-wave Doppler signals and diastolic time intervals from 238 healthy neonates and infants. Using multiple linear regression analysis, we evaluated the impact of physiological determinants on parameter expression.
  
  
  RESULTS
  Early-filling and atrial-filling peak velocities, early-filling acceleration and deceleration rates, and the atrial-filling time velocity integral reached a climax within 2 months after birth, while early-filling time velocity integral followed increasing throughout the study period. The isovolumic relaxation time was found to be significantly longer for neonates than for infants older than 2 months. The observed parameter movements could be attributed to changes of stroke volume and mitral valve area for early filling-time velocity integral (R2 = 0.93), and of heart rate, stroke volume, and mitral valve area for early filling peak velocity (R2 = 0.84), and atrial-filling time velocity integral (R2 = 0.65). Isovolumic relaxation time and atrial-filling peak velocity became heart rate dependent not before 3 months after birth.
  
  
  CONCLUSIONS
  The observed parameter changes are powerful indicators for the maturational process in diastolic function. This process is mainly completed by 3 months of age.
authors.affiliation: Department of Pediatric Cardiology, Charité Medical Center, Humboldt-University of Berlin, Augustenburger Platz 1, D-13353, Berlin, Germany. lothar.schmitz@berlin.de
authors.forename: L
authors.initials: L
authors.lastname: Schmitz
authors.forename: A
authors.initials: A
authors.lastname: Xanthopoulos
authors.forename: H
authors.initials: H
authors.lastname: Koch
authors.forename: P E
authors.initials: PE
authors.lastname: Lange
mesh_terms: D016275:Atrial Function; D003971:Diastole / Q000502:physiology*; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D013318:Stroke Volume; D016277:Ventricular Function, Left / Q000502:physiology*