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 ยฐ 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-ESi, 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.
Segmental wall contraction
Cineangiogram Computer program Percentage shortening of short axes