A computer program for detection of segmental contraction abnormalities by the left ventricular cineangiogram

A computer program which enables detection of segmental abnormalities of the left ventricular contraction was developed using the principles of Leighton et al. [Circulation 50 (1974) 121–127]. A film projector, a digitizer a graphic display and a mini-computer are used. The end-diastolic (ED) and end-systolic (ES) left ventricular silhouettes are traced from 30° right anterior oblique cineangiograms projected on a screen of the film projector. The program determines semi-automatically both apexes and longitudinal axes of the left ventricle. Lines [(N − 1) ≤ 60] are drawn perpendicular to longitudinal axes, dividing longitudinal axes into equal N segments, respectively. These perpendicular lines are extended to intersect ED and ES silhouettes at 2(N − 1) points, respectively. The distances along each of 2(N − 1) hemiaxes are defined as short axes [S-EDi and S-ESi, i = 1 ∼ 2(N − 1)]. Segmental wall contractions are expressed as a percentage of the distance from S-EDi to S-EDi, and displayed as a graph with normal values (mean ± 2 SD). The presence and extent of segmental contraction abnormalities can be evaluated quantitatively by observing a percentage of segmental wall contractions. This program greatly facilitates a correct diagnosis in clinical use.