Regional left ventricular wall motion.

To the Editor: The work of Ingelsl represents a serious effort to grapple with the difficult problem of accurately assessing regional left ventricular wall motion. Since the left ventricular wall motion myocardial markers were used as a standard of segmental wall motion, the evaluation of the five methods of wall motion assessment is dependent on the reliability of that standard. I wonder if midmyocardial markers truly reflect endocardial position at end-systole. An echocardiogram showing vigorous posterior left ventricular wall thickening in systole suggests that endocardial and epicardial motion are not necessarily similar. Where along the gradient of motion would one find the midmyocardial marker? Another potential problem with discrete markers aligned in a plane is the inability to distinguish rotational motion from truly contraction generated inward motion. For example, take a cut-out of figure 1 and place pinholes as markers in the manner indicated in that diagram. Shine a bright light toward the silhouette and note the shadows cast on a paper below when the silhouette plane is parallel to the paper on which the shadow is cast. Now rotate the silhouette and note the marker locations on the paper below. The markers appear to have moved inward. The analogy is clear. Rotational motion of the ventricle about its long axis could give an illusion of contraction where none had occurred. If the heart rotates about the long axis, this should be seen in the left anterior oblique projection. Have these investigators viewed the marker placement at systole and diastole in the left anterior oblique view to assess rotation of the markers versus inward contractile motion? HARRIS J. GELBERG, M.D. Division of Cardiology Sansum Medical Clinic Santa Barbara, California