[Development of a method for the quantitative evaluation of the regional kinetics of the left ventricle]

Segmental wall motion abnormalities of the left ventricle frequently occur in ischemic heart disease. An objective, quantitative method is required to ensure the reproducibility of the assessment of left ventricular regional function, especially in evaluating the changes induced by diagnostic and therapeutic interventions. In 32 normal subjects we obtained 30 degrees right anterior oblique left ventriculograms and developed a method based on the following observations. The method should reflect the symmetric uniform motion of the left ventricular silhouette. Only actual contractile motion should be taken into account; therefore, rotatory and translational motion should be compensated for. Passive systolic movement of aortic and mitral valves accounts for the contraction of neighbouring myocardial segments. Left ventricular wall excursion is most often measured by a coordinate system: since the cavity of the left ventricle becomes relatively longer during systole, left ventricular walls contract neither toward a single central point nor toward the long axis; therefore the appropriate origin of the coordinate system will be a segment. Furthermore, as more elongated left ventricular end-diastolic silhouettes appear to show a greater extent of systolic lengthening (we show evidence of this), the length of the segment must be related to the end-diastolic shape. The basic steps of the method are: 1) identification of a symmetry line, from the aortic mid-point to the apex, by connecting the mid-point of 19 diameters perpendicular to the long axis; 2) roto-translation of the end-systolic silhouette so that the end-systolic apex and aortic mid-point lie on the symmetry line.(ABSTRACT TRUNCATED AT 250 WORDS)