In 19 patients with healed myocardial infraction and normal right ventricular pressures, right and left ventricular volumes (biplane cineangio), ejection fractions and pressures were measured. Twelve of the patients had proximal severe stenosis of the right coronary artery (Group A), which was not diseased in seven patients (Group B). RV mean velocity of diameter shortening (VD) and LV mean velocity of circumferential fiber shortening Vcf) were calculated. Group A and B had similar RV systolic pressures (26.3 +/- 1.0 and 24.7 +/- 2.1 mm Hg) and LV hemodynamics (LVP: 127.5 +/- 5.9 and 122.1 +/- mm Hg, LVPED: 13.1 +/- 1.0 and 13.9 +/- 1.0 mm Hg, LVEF: 45.3 +/- 3.8 and 48.4 +/- 4.6%, Vcf: 0.768 +/- 0.114 and 0.861 +/- 0.123 circ/s). Only LVEDV was significantly higher in Group A (135.3 +/- 6.0 and 103.7 +/- 5.4 ml/m2). RVEDV (Group A: 131.4 +/- 4.5 and Group B: 87.9 +/- 4.8 ml/m2), RVEF (48.8 +/- 1.9 and 56.0 +/- 1.0%), RVPED (6.1 +/- 0.8 and 4.0 +/- 0.4 mm Hg) and VD (0.628 +/- 0.049 and 1.073 +/- 0.082 D/s) indicated significantly impaired RV function in Group A. It can be concluded that coronary artery disease of the right coronary causes significant functional impairment of the right ventricular myocardium.