Assessment of anthracycline-induced cardiotoxicity with electrocardiography

Monitoring of anthracycline-induced cardiotoxicity with electrocardiography (ECG) and comparing ECG changes with findings on echocardiography (ECHO).

A total of 26 adult acute leukemia patients (mean age 46.2 -/+ 12.4 years, 15 males) treated with 2-6 cycles of anthracycline-based chemotherapy (CT) were studied. Cardiac evaluation was performed at the baseline (before CT), after first CT, after last CT (cumulative anthracycline dose 464.3 -/+ 117.5 mg/m2) and circa 6 months after CT. Time ECG parameters, QRS voltage, presence of repolarization changes, arrhythmias and other abnormalities were evaluated.

During treatment and follow-up, we found a statistical significant QTc interval prolongation - 414.7 -/+ 16.0 ms (before CT), 419.6 -/+ 21.6 ms (after first CT), 428.0 -/+ 16.2 ms (after last CT) and 430.1 -/+ 18.4 ms (6 months after CT). Significant QTc interval prolongation (> 450 ms) occurred in 3 patients after first CT, in 4 patients after last CT and in 5 patients within 6 months after CT. Significant total QRS voltage lowering in the limb leads (> 1.0 mV versus before CT) occurred in 3 patients after first CT, in 5 patients after last CT and in 6 patients within 6 months after CT. We found a statistically significant correlation between decreased QRS voltage, QTc interval prolongation and left ventricular (LV) dysfunction on ECHO. Repolarization changes associated with oncology treatment were present in 9 patients within 6 months after CT.

Anthracycline treatment is associated with changes in electrical activity of the myocardium. Prolonged QTc interval represents a risk for development of malignant ventricular arrhythmias. Decreased QRS voltage and prolonged QTc interval after anthracycline treatment could correlate with LV dysfunction on ECHO. Further studies will be needed to prove whether these ECG changes could serve as an accessible and non-invasive screening method indicating LV dysfunction after anthracycline treatment.