Left ventricular transmural systolic function by high-sensitivity velocity measurement "phased-tracking method" across the septum in doxorubicin cardiomyopathy

The clinical usefulness of doxorubicin is limited by doxorubicin-induced cardiomyopathy (DoxCM). The prognosis of this disorder is poor, and a sensitive noninvasive method for detection of DoxCM is strongly required. In this study, we examined if the transmural systolic function (TSF) obtained by the novel phased-tracking method is capable of supplying new information on DoxCM. A total of 18 healthy subjects and 30 patients with acute lymphoblastic leukemia were examined for TSF, as defined by the transmural profile of % thickening obtained by measuring the velocity at each preset point of 0.75-mm intervals. The total number of measurements was 94. In the patients, a decrease in both the peak velocity and the systolic layer thickening was observed, even in the subclinical phase of the normal ejection fraction. For healthy subjects, systolic thickening occurred in the left ventricular (LV) side of the interventricular septum (IVS), and was characterized by a sharp single-peak configuration of the profile. For the patients, however, the peak became dull and/or unclear, which indicates that a change in transmural functional distribution occurred. We concluded that the TSF is a useful measure for diagnosis of the early phase of DoxCM.