Background Heart rhythm disorders are one of major adverse effects induced by myocardial anthracicline cardiotoxicity in children with malignancies and that require early diagnosis for effective prevention.
Objectives To investigate the utility of the study of QT and QTc dispersion in children with malignancies treated with anthracyclines.
Methods patients: 40 patients (2–18 years) with malignant hemopathies, treated with anthracyclines. All patients were examined by clinical examen, ECG, Doppler echocardiography, the values of QT dispersion (difference between the maximum and minimum QT interval, manually measure the QT interval, on three successive cardiac cycles) and QT dispersion (Bazett’s formula). Dispersion of QT and QTc interval in these patients was compared to similar values from 20 healthy children without cardiovascular history.
Results The increase of QT and QTc dispersion in patients comparative to the control lot, was revealed in 73% cases, usually in those which had a cumulative anthracyclines doses over 400 mg/ m2, with medium values of QTD: 53,33 ± 10,18 msec and QTcD: 66,28 ± 12,8 msec. The increased dispersion of QT and QTc intervals was highlight most frequently in cases with echocardiographycal signs of anthracyclines cardiotoxicity, even only diastolic dysfunction of left ventricle.
Conclusions The significant incidence of increasing the QT and QTc interval dispersion in patients who received treatment with anthracyclines and the correlation with cumulative anthracyclines doses and echocardiographic modifications, especially diastolic dysfunction, proves utility of systematic investigation of QT and QTc intervals dispersion in the full control in the therapy, as an earlier marker for cardiotoxicity of anthracyclines.