According to the characteristics of changes of heart and lung function at different stages 25 patients with rheumatic valvar heart disease could be classified into three stages: 1. The stage of normal lung ventilation and volumes; 2. Stage of obstructive ventilatory function; 3. The stage of mixed ventilatory defects associated with right heart failure. As pulmonary artery pressure increased right ventricle work became elevated and left ventricle work decreased. There was an inverse correlation of vital capacity with per minute work of right ventricle.