The multicentric character of normal left ventricular wall motion. Implications for the evaluation of regional wall motion abnormalities by contrast angiography

Current radiologic approaches to evaluation of regional ventricular wall motion generally employ rectilinear hemichords (“hemiaxes”) or radial hemichords (“chords”) defined by the presumptions that wall segments move either perpendicularly toward the ventricular long axis, or toward some common center, respectively. In order to test these presumptions, the end‐systolic and end‐diastolic frames of 17 normal right anterior oblique (left) ventriculograms were analyzed, using a digitizer and a computer. The motion vectors of 47 points on each ventriculographic perimeter were defined by centers (located along the ventricular long axis). Twenty average centers were found which could be represented by three centers, for six regions of the normal angio‐graphic silhouette. Computer models of abnormal regional wall motion, using three centers, disclosed appreciable discrepancies among the chord, hemiaxis and rectilinear area methods, particularly for the apical and basal wall regions. The model data suggest that the wall region, iself, dictates the center which should be used for measuring an abnormality of regional wall motion.