Advantages and applications of the centerline method for characterizing regional ventricular function.

TLDR

The study aims to delineate the theoretical benefits and uses of the centerline method for assessing regional ventricular function. The method measures motion along 100 chords perpendicular to a centerline between end‑diastolic and end‑systolic contours, normalizes for heart size, expresses abnormalities in standard‑deviation units, and employs a sliding window to capture local motion without requiring a fixed coordinate system. The mean abnormality across 100 chords correlates strongly with area ejection fraction (r = 0.97), regional abnormality extent can be quantified, and hypokinesis severity at myocardial infarction sites correlates more closely with infarct size from creatine kinase (r = –0.78) than with ejection fraction or circumferential extent.

Abstract

We sought to identify theoretical advantages and applications of the centerline method for quantitative assessment of regional ventricular function. Motion was measured along 100 chords constructed perpendicular to a centerline drawn midway between the end-diastolic and end-systolic contours, and normalized for heart size. Abnormality was expressed in units of standard deviations from the mean motion in a normal reference population to indicate both the severity and significance of the wall motion abnormality. The mean abnormality averaged over 100 chords correlated highly with the area ejection fraction (r = .97). The centerline method uses a "sliding window" to measure motion where it is abnormal, because assessment of wall motion in predefined regions of the ventricular contour underestimates abnormality. From the 100 data points, the extent (% of contour) of regional abnormalities can also be determined. The severity of hypokinesis at the site of acute myocardial infarction correlated better with infarct size estimated from creatine kinase release (r = -.78) than did the ejection fraction or the circumferential extent of hypokinesis. Because the centerline method measures motion along locally determined vectors, and requires no apex, origin, coordinate system, or geometric reference figure, it can be applied to contours as dissimilar as the 60 degree left anterior oblique projection of the left ventricle and the 75 degree left anterior oblique projection of the right ventricle.