The catheterization of right and left compartments of the heart and cinecoronaroventriculography were carried out in 92 patients with chronic post-infarction left-ventricular aneurysm. Fifty-four patients (group 1) showed no clinical signs of heart failure or just a first-stage failure, and 38 patients (group 2) had heart failure at stages IIA and IIB. Highly significant intergroup differences were demonstrated between pressure values in the pulmonary artery (28.7 +/- 1.3 and 48.0 +/- 3.6 mm Hg in groups 1 and 2, respectively), pulmonary capillaries (13.5 +/- 0.7 and 21.4 +/- 2.0 mm Hg), the right atrium (7.1 +/- 0.4 and 9.7 +/- 0.7 mm Hg) as well as right-ventricular end diastolic pressure (6.6 +/- 0.5 and 10.6 +/- 1.0 mm Hg). It is suggested that pulmonary circulation adequately reflects the clinical stage of chronic heart failure in patients with post-infarction left-ventricular aneurysm. Impaired blood outflow from pulmonary veins due to reduced ventricular pump function and inadequate elasticity of the ventricular wall is the primary link in the pathogeny of pulmonary hypertension in patients with left-ventricular aneurysm.