Variability in the measurement of regional left ventricular wall motion from contrast angiograms.

Abstract

Four types of variability affecting quantification of regional wall motion from contrast left ventriculograms (LVgrams) were studied. These included beat-to-beat variability in 24 LVgrams, intraobserver and interobserver variability in 20 LVgrams, and study-to-study variability in serial LVgrams of 21 patients with stable coronary artery disease. Motion was measured at 100 equidistant chords perpendicular to a center line drawn midway between the end-diastolic and end-systolic contours and normalized for heart size. Variability was computed as the absolute difference between observations. Beat-to-beat, intraobserver, and interobserver variability at the 100 chords were similar, averaging 14%, 14%, and 17%, respectively, of the mean motion in 64 patients with normal ventriculograms. Study-to-study variability was significantly higher, averaging 30% of mean normal motion, but was reduced when regional motion was calculated as the mean motion of chords within a region of interest. Variability peaked at the apex. Realignment to correct for cardiac rotation significantly increased variability. Investigators whose methods of wall motion analysis rely on identification of the apex as a landmark should be aware of this source of potential variability and error. Circulation 68, No. 3, 550-559, 1983. IT HAS LONG BEEN KNOWN that coronary artery stenosis results in abnormal regional left ventricular wall motion. ' Early studies in which wall motion was gauged subjectively were hampered by large interobserver variability that resulted in poor reproducibility of results.2-More recently, quantitative methods of measuring regional wall motion have been developed. With these methods, wall motion abnormalities in patients with coronary artery and valvular disease have been measured and related to the site and severity of coronary disease, to the amount of fibrosis in infarcted myocardium, and to the development of congestive heart failure.5'-' The reproducibility or variability in motion measurements by the various quantitative methods, however, has not yet been determined. Knowledge of variability is necessary to gauge the significance of measured abnormalities in wall motion and of changes observed in serial studies performed to assess progression of disease or response to a therapeutic intervention. Therefore, our study was performed to determine

Left Ventricular Regional Wall Motion in the Early Neonatal Period.

“…The centerline method of regional wall motion analysis was developed to address these concerns. Its sensitivity and specificity in detecting abnormal regional function compare favorably with rectangular and radial methods (Sheehan et al 1986) and its reliability has been previously documented (Sheehan et al 1983). In our present study, interobserver variability was larger than that of Sheehan's results (1983) measured from ventriculograms.…”

“…Assessment of inter-observer variability indicate that the apex is one of the least reliably visualized parts of the contour. The dependence of rectangular and radial methods on the apex as a landmark in defining a long axis may produce error in wall motion measurement (Sheehan et al 1983). The centerline method of regional wall motion analysis was developed to address these concerns.…”

“…Centerline chord motion analysis, as described by Sheehan et al (1983) used to quantitatively assess regional left ventricular function (Cardio 500; Kontron Medical System, Tokyo) ( Fig. 1).…”

A general technique for automatic left ventricle boundary validation: Relation between gray scale cardioangiograms and observed boundary errors

“…Let I and O be the sets that contain the pixels inside and outside the mutually exclusive moving window. Let G1 and Go be the sum of all the gray scale intensities for pixels that are inside and outside the window given by G,=Egp&Go=Egp (1) …”

A variational approach to cardiac motion estimation based on covariant derivatives and multi-scale Helmholtz decomposition

“…Introduction. In cardiology literature [52] it has been noted that deformation of the cardiac wall provides a quantitative indication of the health of the cardiac muscle. Cardiac motion extraction is therefore an important area of research.…”