Regional wall motion abnormality and its relation to myocardial histopathological change and clinical prognosis in dilated cardiomyopathy. Usefulness of dobutamine loading echocardiographic study.

Abstract

Regional wall motion abnormality in 28 patients with dilated cardiomyopathy (DCM) was evaluated by M-mode and two-dimensional echocardiography (2DE) before and during dobutamine administration. In 6 autopsied hearts obtained from deceased cases during the follow up period, the relationship between regional myocardial fibrosis and wall motion abnormality was investigated. Left ventricular wall was divided into 11 segments by 2DE. The wall motion of each segment was evaluated and scored into 4 degrees (0: normokinesis, 1: hypokinesis, 2: severe hypokinesis, 3: akinesis or dyskinesis), and the total sum of wall motion abnormality scores in 11 segments (TWS) for each case was calculated. Wall motion abnormality was observed in 231 of the total 308 segments, and in 121 of the 231 segments, the severity of the wall motion abnormality was reduced by dobutamine administration. The rate of fibrosis was lower in segments with improved wall motion abnormality than in those without improvement. Sixteen deteriorated or deceased cases during the follow up period (D group) had larger TWS than 12 non-deteriorated cases (ND group), but percent fractional shortening (%FS) obtained by M-mode echocardiography was not significantly different between the 2 groups. The changes in %FS and TWS by dobutamine (delta%FS, %delta TWS) were significantly larger in ND group than in D group. The cases with %delta TWS greater than or equal to 45% were all in the ND group, and all deceased cases had the value of %delta TWS less than or equal to 36%. Thus, the observation of regional wall motion by dobutamine loading echocardiography was useful for evaluating regional histopathological findings and prognosis in patients with DCM.