The role of daily ECG-monitoring in the myocardial injury diagnosis on the background of anthracycline low cumulative doses in patients with acute leukemia in combination with ischemic heart disease

Abstract

Anthracycline-induced cardiotoxicity is a complicated problem of treating patients with acute leukemia (AL), which can lead to the acute cardiac events development. Ischemic heart disease (IHD) is one of the cardiotoxicity risk factors, which requires monitoring of changes in myocardial bioelectric activity on the background of anthracycline low cumulative doses (CDs) in these patients. Aim: To assess the nature of electrocardiogram (ECG) changes on the background of anthracycline low CDs in patients with AL taking into account concomitant ischemic heart disease. Materials and methods. The study involved 93 patients with newly diagnosed AL (acute lymphoblastic leukemia – 21 pts, acute myeloid leukemia – 72 pts), mean age 16-72 years, 48 (51.8%) men, 45 (48.2%) women, ECOG I-II. Their polychemotherapy (PCT) programs included anthracyclines. According to the presence of concomitant IHD patients were divided into two groups: I (n=57) – AL patients without concomitant IHD; II (n=36) – AL patients with concomitant IHD. The standard 12-lead ECG and daily ECG-monitoring were performed for patients of both groups in achieving the CD from 100 to 200 mg/m2 for doxorubicin, which amounted 179.5 ± 24.11 mg/m2 and 172.1 ± 23.15 mg/m2 in patients of groups I and II respectively. Results. The sinus tachycardia, repolarization processes violations and QRS complex voltage reduction were registered in 16 (28%) pts of group I according to the standard 12-lead ECG. In 29 (80.5%) pts of group II on the sinus tachycardia background the following changes were revealed: right bundle branch block – in 2 (5.6%) pts, left anterior fascicular block – in 2 (5.6%) pts, first-degree atrioventricular block – in 2 (5.6%) pts, supraventricular extrasystoles – in 4 (11.1%) pts, lower voltage and repolarization processes reduction – in 8 (22.2%) pts. The ST segment depression was registered in 13 (36.1%) pts, the Q-T interval prolongation – in 6 (16.6%) pts, T wave changes – in 6 (16.7%) pts of group II. According to the daily ECG-monitoring in 28 (49%) pts of group I with minimal physical activity on the tachycardia background the episodes of solitary supraventricular extrasystoles were detected. In all 36 (100%) patients of group II the periods of tachycardia were recorded, that were accompanied by the increasing number of single supraventricular extrasystoles, episodes of paired and group supraventricular extrasystoles – in 24 (66.6%) pts, single episodes of ventricular extrasystoles – in 19 (52%) pts and increased number of clinically significant ST segment depression periods – in 29 (80.5%) and Q-T prolongation – in 14 (38.8%) patients. Low CDs up to 100-200 mg/m2 for doxorubicin in AL patients without ischemic heart disease are accompanied by the cardiotoxic effects development in the form of arrhythmias: sinus tachycardia, supraventricular extrasystoles. In case of concomitant ischemic heart disease presence the complex of myocardial bioelectric activity disorders develops, such as arrhythmias, conduction abnormalities and silent myocardial ischemia. With the purpose of early anthracycline-induced cardiotoxicity diagnosis in patients with AL receiving PCT it is necessary to conduct daily ECG-monitoring, which has greater sensitivity compared with standard 12-lead ECG.