Using 99m Tc-pyrophosphate there is a positive visualization of a transmural myocardial infarction by a localized tracer activity outside of the skeletal system. The uptake of the tracer in the infarcted area is expressed as percentage of the accumulation over the sternum. It reaches a maximum 48-60 hours after infarct onset and then recedes gradually but not strictly linearly. On the occasion of a control scintigraphy 3-4 weeks after the myocardial infarction and after full mobilization 56 per cent of the investigated patients showed a variable decrease of the tracer activity. On 44 per cent the tracer activity in the infarcted area remained unchanged or even increased slightly, though the infarction could be excluded. At the same time performed haemodynamic investigations with measuring the pulmonary artery pressure at rest and under stress conditions showed a good correlation between the persistence of the tracer activity in the infarcted area and the amount of the pulmonary pressure at rest and during stress, manifesting left ventricular function. So the result of a control scintigraphy 3-4 weeks after myocardial infarction allows to draw prognostic inferences about the further course of the disease.