[Idiopathic dilatation of the pulmonary artery. Echocardiographic aspects].

The authors compared 30 patients with at least one clinical sign of idiopathic dilatation of the pulmonary artery, with a group of 20 normal control subjects in order to establish diagnostic criteria for this condition. In the first group, 17 had characteristic radiological findings and 13 others had clinical signs of idiopathic dilatation of the pulmonary artery. Comparison with the control group showed significant differences (p < 0.05) in 4 parameters: 1) the diameter of the pulmonary artery at the bifurcation/m2 body surface area (2.8 +/- o.4 cm versus 2.4 +/- 0.4 cm), 2) the diameter of the aorta 2 cm beyond the aortic valve/m2 of body surface area (1.7 +/- 0.3 cm versus 2.1 +/- 0.7 cm), 3) the ratio of pulmonary artery/aortic diameters at the valve rings (1.4 +/- 0.2 versus 1.1 +/- 0.02); 4) the ratio of the aorta 2 cm beyond the valve/aortic ring (1.02 +/- 0.07 versus 1.09 +/- 0.09). The diagnostic criteria of idiopathic dilatation of the pulmonary artery in the absence of cardiac or pulmonary disease are: 1) ratio of pulmonary artery diameter at its bifurcation/aortic ring diameter or 2 cm beyond the aortic valve of > or = 1.4; 2) ratio of pulmonary/aortic ring diameters > or = 1.5.