It may be established that the complex cardiopulmonary functional diagnostics in patients with chronic ischaemic heart disease obtained the following essential results: 1. The ergometrically achieved total functional capacity is clearly decreased in all age groups compared with the healthy persons, the differences are highly significant. 2. The proof of a coronary insufficiency got by the electrocardiogram after work is to be regarded as a factor limiting the functional capacity. 3. 72% of the patients reveal under load a PAEDP increased more than the normal of 25 Torr. After exclusion of a respiratory insufficiency these findings must be regarded as a disturbed myocardial function. 4. Thus the increased PAEDP under load apart from the well-known triad (angina pectoris under load, decreased total functional capacity, pathological ECG after work) is a sensitive and decisive factor for proving the disturbed cardial function in chronic ischaemic heart disease.