[Synopsis of the interactions of heart and lung function].

Due to the close connection between the functions of heart and lung there are no pathological changes in the one system without altering the physiology of the other. The interactions between heart and lung and their possible reactions are shown in some selected examples. On the one hand, in advanced lung diseases and in cor pulmonale one has to be on the look-out for concomitant disturbances of the left ventricular function for diagnosis, prognosis and therapy and on the other hand, there are deteriorations of chronic heart diseases due to secondary bronchopulmonary diseases. The treatment of combined cardiopulmonary disorders requires particular care.