Heart function can be investigated non-invasively and without risk for the patient by means of radionuclide ventriculography. Coronary artery disease can be diagnosed with high sensitivity and distinguished from other diseases of the heart with high specificity by typical alterations of heart function as seen in rest and/or exercise scans. The hemodynamic significance of invasively proven stenoses of coronary arteries can de demonstrated and the function and functional capacity of surviving vital myocardium after myocardial infarction can be quantified scintigraphically. The efficacy of medical and surgical therapy can be documented and the course of disease can be followed up.