Evaluation of functional parameters and left ventricular size by radionuclide ventriculography (RNV) in myocardial infarction patients.

Functional parameters like left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and left ventricular size index were evaluated in 68 patients with myocardial infarction and in 50 normal subjects, by radionuclide ventriculography (RNV). Patients were divided into four groups (I to IV) according to increasing left ventricular size and the parameters were evaluated in each group. LVEF proved to be the most sensitive parameter of overall left ventricular performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that in extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a greater fall in left ventricular compliance. LV size and performance were least affected in inferior wall myocardial infarction. LVEF was however a better predictor of LV size than the site of the myocardial infarction.