The distortion from the physiological profile of the transmural systolic function of the myocardium in doxorubicin cardiomyopathy

摘要

The clinical usefulness of doxorubicin is limited by the cardiomyopathy (DoxCM) it causes. The prognosis of this disorder is poor and a more sensitive, noninvasive method for DoxCM is required. We examined whether the transmural systolic function (TSF) by Phased Tracking Method (PTM) supplies new information for DoxCM. 18 normal subjects and 30 patients (acute lymphoblastic leukemia) were examined for TSF (the velocity at each preset point of 0.75mm-intervals across the septum and the transmural profile of %thickening, 94 measurements). In patients, decreases in TSF were observed (the peak velocity, 0.034±0.007 m/s vs 0.024±0.010; %thickening, 223±46 % vs 169±34, normal vs DoxCM). These deteriorations of TSF were observed even at a subclinical phase of the normal ejection fraction. Peak systolic thickening occurred at the left-side of the septum in normals with a sharp, single peak configuration of the profile (% systolic thickening at each 1/3 of the septum from the right to left ventricular side were 27.6±2.6 %, 31.8± 2.4 %, and 40.4±3.0 %, respectively in normals). However, the peak became dull and/or unclear in this transmural systolic functional profile across the wall in DoxCM, suggesting myocardial systolic damage occurred heterogeneously across the wall. From the multiple regression analysis, transmural heterogeneity was independent of the conventional parameters of the ventricular function. Quantitative information on DoxCM obtained by assessing the myocardial layer thickening using PTM could be useful for the rational management of patients of leukemia, malignant lymphoma, or other serious diseases requiring treatment with doxorubicin.