Systolic heterogeneity of transmural myocardial function in normal subjects: physiological functional heterogeneity

Noninvasive early detection of anthracycline-induced cardiotoxicity in patients with hematologic malignancies using the phased tracking method

Anthracyclines are among the most effective and widely used anticancer drugs; however, their use is limited by serious cardiotoxicity. Early detection is necessary to prevent the high mortality rate associated with heart failure (HF). We evaluated cardiac function in 142 patients using conventional echocardiography and the phased tracking method (PTM), which was measured using the minute vibration and the rapid motion components, neither of which is recognized in standard M-mode nor in tissue Doppler imaging. For systolic function comparison, we compared left ventricular ejection fraction (LVEF) in conventional echocardiography with the average velocity of ventricular septum myocytes (Vave ) in the PTM. The Vave of 12 healthy volunteers was 1.5 (m/s)/m or more. At baseline of 99 patients, there was a positive correlation between LVEF and Vave in all patients. There were no significant differences in baseline cardiac function between patients with and without HF. There was a negative correlation between the cumulative anthracycline dose and LVEF or Vave among all patients. We determined that Vave 1.5 (m/s)/m was equivalent to LVEF 60%, 1.25 (m/s)/m to 55%, and 1.0 (m/s)/m to 50%. During the follow-up period, there was a pathological decrease in LVEF (<55%) and Vave (<1.25 m/s/m) in patients with HF; decreases in Vave were detected significantly earlier than those in LVEF (P < 0.001). When Vave declined to 1.5 (m/s)/m or less, careful continuous observation and cardiac examination was required. When Vave further declined to 1.0 (m/s)/m or lower, chemotherapy was postponed or discontinued; thus, serious drug-induced cardiomyopathy was avoided in patients who did not relapse. The PTM was superior to echocardiography for early, noninvasive detection and intermediate-term monitoring of left ventricle systolic function associated with anthracycline chemotherapy, among patients with hematologic malignancies. The PTM was an effective laboratory procedure to avoid the progression to serious cardiomyopathy.

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.