[A new radioisotopic method of studying local ejection fractions. Application to the study of abnormalities of left ventricular contraction].

The authors describe a new method of segmental analysis of the left ventricle by equilibrium gamma cinecardiography. The left ventricle in the left anterior oblique projection was divided into 16 triangular sectors with reference to the centre of gravity of the radioactivity of the end diastolic frame. The following parameters were calculated for each sector (the spatial equivalent of a quarter of an orange): end diastolic, end systolic and ejection activity and the regional ejection fraction. The percentage of normal and asynergic regions was deduced. The end diastolic activity of regions with ejection fractions of over 0,47 was compared to the total end diastolic activity to obtain the percentages. This method of segmental division has the advantages of being completely automatic, based entirely on an objective reference calculated by computer and of giving very reproductible quantitative results. The clinical applications in a series of I400 patients examined by this method were numerous (the detection of dyskinesia in acute myocardial infarction). It was particularly useful in chronological and follow-up studies (exercise scintigraphy before and after glyceryl trinitrite).