Cardiomegaly--what does it mean? A comparison of echocardiographic to radiological cardiac dimensions in children.

Several cardiac dimensions were estimated by echocardiography and plain chest films in 36 healthy children and 85 children with heart disease. Left and right ventricular volumes and left ventricular mass were estimated by echocardiography, and compared with the cardiothoracic ratio, cardiac frontal area, and total cardiac volume, estimated from x-rays films. In healthy children there was poor correlation between the radiological and echocardiographic estimates. In children with heart disease, there was a close correlation of radiographic total cardiac volume with echocardiographic left ventricular volume and mass, and combined ventricular volumes. Cardiothoracic ratio and cardiac frontal area did not correlate with echocardiographic data. For a more reliable evaluation of the heart size, in children as in adults, the total cardiac volume has to be calculated from both the frontal and lateral films, as estimates obtained from only a frontal film are unreliable.