Dynamic changes in left ventricular free wall thickness in the human heart.

Sufficient delineation of differences in density is often not achieved by standard x-ray cinematographic technic. As a result, when cineventriculography is used to study the shape and motion of the left ventricle, its free wall is often defined imprecisely, if at all. This problem has been overcome by utilization of a special color-coded, triple-emulsion cine film in place of the usual black and white film. The resulting photographic images permitted analysis of wall dynamics and measurement of wall thickness in different planes of the heart. Thickening of the normal wall during systole averaged between 70 and 106%, but with inconsistent nonuniform regional changes within this range. In the diseased left ventricle with localized areas of paradoxical expansion, markedly reduced if any thickening of the wall occurred during systole.