Influence of age and sex of the patient on myocardial scintillography with radiophosphates
Cuarón, A.; Acero, A.P.; Cárdenas, M.
Archivos del Instituto de Cardiologia de Mexico 50(2): 141-150
1980
ISSN/ISBN: 0020-3785 PMID: 7416861 Document Number: 162139
Myocardial 99mTc labeled phosphate myocardial images (205) were classified according to the sex and age of 185 patients. A format with 6 degrees of myocardial phosphate concentration, related to that in bone, was used to interpret the scans. Five different criteria levels represented a positive image. The optimal criteria level for each clinical group was when the images showed a myocardial concentration lower than in bone (2+), with a focal distribution pattern. Sensitivity, specificity and accuracy were calculated for each criteria level in each clinical group. Sexual differentiation factors apparently exert no influence on the clinical execution of the procedure. A gradual decrease with age of the values of the 3 statistical parameters was observed. The decrease on sensitivity seems to be due to a lower influx of the radiophosphates to the agonic myocardial cells, caused by a decreased capacity in building up a collateral coronary pathway. The influence of other organic or biochemical factors that may compete with the infarcted myocardium for the circulating radiophosphates was not excluded. The decrease of specificity is a frequent consequence with increased age of cardiac processes, other than infarction, which concentrate the radionucleotide.