Scintigraphic Myocardial Imaging with 99mTc-Labelled Pyrophosphate of Experimentally Produced Cardiomyopathy in Dogs

In 10 dogs experimental cardiomyopathy was produced using high intravenous doses of adrenaline and theophylline. The possibility of scintigraphic detection of this non-ischaemic damage was tested by means of 99mTc-gluconate. In 5 dogs the scintigraphic examination was carried out 4 hrs following the production of the damage. In all 5 cases a marked positivity of the heart scan was observed. The finding was confirmed by the radioactivity of tissue samples from all sections of the heart. In 3 out of 5 dogs the histological examination of the myocardium (PAS and HBFP staining) was positive. In the remaining 5 dogs the scan was performed 24 hrs following the development of the damage. A positive scintigraphic finding was observed in 4 cases, the degree of accumulation being lower than at 4 hrs. The radioactivities of tissue samples were also significantly lower as compared with the 4-hr values. In contrast, the histological findings were markedly positive in all 5 dogs. It follows that 99mTc-gluconate is capable of detecting in addition to infarctions non-ischaemic damages to the myocardium, too. The normalization of the finding is very quick. This experimental finding appears to be of importance in clinical practice.