Left atrial and left ventricular function in healthy children and young adults assessed by three dimensional echocardiography.

OBJECTIVE

To establish normal values of left atrial and left ventricular volumes and function in children and young adults using three dimensional echocardiography (3DE).

METHODS

169 healthy subjects aged 2 to 27 years were studied by digitised 3DE. 3DE was achieved using rotational acquisition of planes at 18 degrees intervals from the parasternal view for the left atrium and from the transthoracic apical view for the left ventricle with ECG gating and without respiratory gating. Left atrial and left ventricular volumes could be calculated throughout the heart cycle, and the respective time-volume curves were reconstructed in each subject.

RESULTS

For the analysis the subjects were divided into five groups according to body surface area: 0.5-0.75 m2, 0.75-1.0 m2, 1.0-1.25 m2, 1.25-1.5 m2, and over 1.5 m2. Mean (SD) left atrial maximum volume/body surface area was 19.6 (3.5), 21.7 (3.7), 22.0 (4.7), 24.5 (4.8), and 27.4 (6.4) ml/m2; left ventricular maximum volume/body surface area was 50.1 (8.8), 54.9 (10.1), 56.4 (9.9), 58.7 (11.0), and 64.4 (10.3) ml/m2. Left atrial active emptying increased from 19% to 35% with age (r = 0.34, p < 0.001) and with decreasing heart rate (r = -0.28, p < 0.001).

CONCLUSIONS

Transthoracic 3DE is well suited for studying the phasic changes in left atrial and left ventricular volumes in young children as well as in adults. The data obtained from 169 healthy subjects will serve as a reference for further studies in patients with various cardiac abnormalities.