Modification of the centerline method for assessment of echocardiographic wall thickening and motion: a comparison with areas of risk.

The ability of the centerline method to discern regional myocardial risk area was evaluated using two-dimensional echocardiographic measurements and coronary artery occlusion in 16 open chest, anesthetized dogs. The centerline method was modified to allow determination of both wall thickening and wall motion at control and during coronary artery occlusion. End-systolic and end-diastolic echocardiographic images were analyzed at 100 equally spaced points around the centerline of the short-axis view of the left ventricle to determine shortening and thickening abnormalities. In vivo risk regions were assessed by microsphere injection during occlusion, and autoradiographic analysis revealed a mean (+/- SD) circumferential risk area of 37.5 +/- 7.7%. Abnormal function was established by three criteria on the basis of the control values for both fractional shortening and wall thickening: 1) less than 2 SD, 2) less than 95% tolerance limits, and 3) dyskinesia. The criterion of less than 2 SD estimated a risk area of 45.9 +/- 16.7% for fractional shortening and 37.2 +/- 16.8% for wall thickening. Although neither value was significantly different from the actual mean value for the risk region, the results for fractional shortening were greater than for wall thickening (p less than 0.01). The less than 95% tolerance limit method significantly underestimated risk area for both shortening (25.6 +/- 15.1%, p less than 0.05) and thickening (19.1 +/- 12.7%, p less than 0.001), as did analysis by dyskinesia (13.1 +/- 12.1% for shortening, p less than 0.001; 20.6 +/- 12.1% for thickening, p less than 0.01). Thus, modification of the centerline method allowed determination of both fractional shortening and wall thickening from echocardiographic images.(ABSTRACT TRUNCATED AT 250 WORDS)