title: Left anterior descending coronary artery flow and its relation to age in children.
abstract: Recent advances in Doppler and color echocardiographic techniques enable coronary flow dynamics to be estimated even in children. To assess quantitatively left anterior descending coronary artery (LAD) volumetric flow and to determine its relation to age and left ventricular (LV) mass, healthy children participated in a study that used high-frequency transthoracic echocardiography. We also studied whether Doppler echocardiography can reliably measure LAD flow in a clinical setting. In 57 healthy children, 2-dimensional echocardiography was used to measure the diameter and cross-sectional area of the LAD and LV mass. LAD peak flow velocity, flow velocity integral, and flow volume were measured by Doppler echocardiography. We then calculated the ratio of LAD cross-sectional area to LV mass and the ratio of LAD flow volume to LV mass. In 12 patients with Kawasaki disease, LAD flow velocity and flow velocity integral were measured by Doppler echocardiography at the time of Doppler guide wire examination. There were significant correlations between echocardiographic and Doppler guide wire methods for flow velocity and flow velocity integral (r = 0.77 and 0.83, P <.01, respectively). The LAD flow velocity decreased significantly with age (r = -0.43, P <.01). The LAD flow volume per minute increased significantly with age (r = 0.55, P <.01). However, LAD flow volume/LV mass ratio in younger infants was high and decreased significantly with age (r = -0.66, P <.01). This study shows that LAD flow patterns can be reliably assessed by transthoracic Doppler echocardiography in the majority of pediatric subjects. In the current study, the LAD flow velocity and the ratio of LAD flow volume to LV mass in infants was high and decreased with age, suggesting high myocardial perfusion. High LAD peak velocity in infants may be related with high resting coronary flow. Age-related changes in the LAD flow characteristics must be taken into consideration in the study of the coronary circulation in children.
authors.affiliation: Department of Pediatrics, Akita University School of Medicine, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yasuoka
authors.forename: Kenji
authors.initials: K
authors.lastname: Harada
authors.forename: Masamichi
authors.initials: M
authors.lastname: Tamura
authors.forename: Goro
authors.initials: G
authors.lastname: Takada
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001158:Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000502:physiology*; D015150:Echocardiography, Doppler; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D007229:Infant Welfare; D007231:Infant, Newborn; D015588:Observer Variation; D012016:Reference Values; D015203:Reproducibility of Results; D016276:Ventricular Function