Normal values for left anterior descending coronary artery flow velocity assessed by transthoracic doppler echocardiography in healthy children.

Normal values for left anterior descending coronary artery (LAD) flow velocity were assessed from a large number of normal children. In 303 healthy children, LAD peak flow velocity was measured by Doppler echocardiography. LAD peak flow velocities were calculated considering the angle between the Doppler beam and the coronary flow direction. The flow signals of LAD were recorded in 95% (288/303). The mean angle between the Doppler beam and Doppler flow signals of LAD was 42 +/- 8 degrees. The ratio of AT to total diastolic spectral duration was 0.19 +/- 0.088 and constant with age. LAD peak flow velocity correlated significantly with age (r = -0.57, p < 0.0001) and heart rate (r = 0.63, p < 0.0001). Multiple linear regression analysis showed that LAD peak flow velocity was associated with age and heart rate (LAD peak flow velocity = 20-0.34 (age) + 0.16 (heart rate), r2 = 0.41, p < 0 .0001). Normal data obtained in the present study provide a basis of the understanding and investigation in children with congenital heart disease or acquired heart disease such as atherosclerosis, left ventricular hypertrophy, or Kawasaki's disease.