The role of corrected QT interval in the cardiologic follow-up of young patients treated with Adriamycin

Abstract

The behavior over time of the corrected QT interval (QTc) in patients treated with Adriamycin (ADM) was evaluated in order to detect any possible correlations between the modifications of the QTc duration and the cardiac function of patients treated with different cumulative doses of ADM (360, 390, 480 mg/m2).

Patients and methods: Electrocardiograms (ECGs) performed 2 months (178 patients), 1 year (65) and 3 years (43) after the completion of chemotherapy, were examined.

Results: after 2 months a prolonged QTc interval (> or = 0.45 sec) was found in 50% of patients, after 1 year in 26% and after 3 years in 14%. The patients treated with the highest dose of the drug (480 mg/m2) showed the highest incidence of prolonged QTc intervals. No patients treated with 360 mg/m2 ADM showed prolonged QTc intervals after 3 years. No correlations between prolonged QTc and functional echocardiographic alterations were noticed. The QTc interval prolongation, easily observable after treatment with ADM, seems to be related to the quantity of the drug administered and is generally a reversible phenomenon. Nevertheless a prolonged QTc can persist after 3 years. The persistence of prolonged QTc intervals is not associated with a higher incidence of functional cardiac deficits which are echocardiographically detectable.