title: Beat-to-beat variability of left ventricular indexes measured by acoustic quantification: influence of heart rate and respiration--correlation with M-mode echocardiography.
abstract: Influence of heart rate and respiration on beat-to-beat variability of left ventricular indexes measured by acoustic quantification was examined. These indexes were correlated with their counterparts measured by M-mode echocardiography. Parameters of left ventricular performance were recorded for 1 full minute in 43 children with a mean age of 5.9 +/- 3.9 years. Beat-to-beat variability was documented. The effect of respiration on such variability was examined in another 10 subjects. A wide range of heart rates and respiration did not show significant influence on the degree of variance among these parameters. The indexes measured correlated well with their counterparts measured by M-mode echocardiography. Acoustic quantification separated those with normal from those with abnormal left ventricular function with the same statistical significance as did M-mode echocardiography. A moderate degree of beat-to-beat variability occurs in acoustic quantification-derived left ventricular indexes. Heart rate variability and respiration do not influence the beat-to-beat variance of parameters of left ventricular performance measured with the acoustic quantification. Excellent correlation was documented between this technique and M-mode echocardiography.
authors: Division of Pediatric Cardiology, Dhahran Health Center, Saudi Arabia.
authors: M A
authors: MA
authors: Seliem
authors: E T
authors: ET
authors: McWilliams
authors: M
authors: M
authors: Palileo
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005583:Fourier Analysis; D006337:Heart Murmurs; D006339:Heart Rate / Q000502:physiology*; D006345:Heart Septal Defects, Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008297:Male; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology; D009200:Myocardial Contraction / Q000502:physiology; D012016:Reference Values; D012119:Respiration / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*