Anthracycline-induced left atrioventricular dyssynchrony in children with leukemia: a cardiac magnetic resonance imaging study of functional and strain analysis.

BACKGROUND: The 2022 European Society of Cardiology on cardio-oncology guidelines emphasized anthracycline chemotherapy's dose-dependent cardiotoxicity, identifying reduced left ventricular (LV) strain as a sensitive biomarker for early myocardial injury. However, left atrial (LA) structural/functional changes assessed via cardiac magnetic resonance (CMR) remain underexplored. METHODS: This cross-sectional cohort study included 109 pediatric leukemia patients (2015-2021) and 40 age-matched controls. Leukemia patients were stratified into low-/high-dose anthracycline groups. CMR parameters (LA ejection fraction [LAEF], LV strain [LVS], LA strain [LAS], and left atrioventricular coupling index [LACI]) were analyzed. Linear regression evaluated strain-LACI relationships; Spearman's correlation assessed LAS-LVS associations. RESULTS: Leukemia patients exhibited higher LA contraction strain (Ɛa: 24% vs. 21%, p = 0.025) but lower total/passive LAEF [73 ± 8 vs. 78 ± 7; 50 [40,56] vs. 59 [53,65]] and higher LV ejection fraction (64.5 ± 5.5 vs. 62.4 ± 5.7) than that in controls. LAS-LVS correlations were stronger in controls (r = 0.32-0.52) than leukemia (r = 0-0.27). Among leukemia patients, low-dose patients had higher active LAEF (48 ± 14 vs. 39 ± 16) and weaker LAS-LVS correlations than high-dose group(r = 0-0.28 vs. r = 0-0.42), while high-dose group showed elevated LACI (β=9.68, p = 0.018) correlating with the cumulative anthracycline dose. CONCLUSIONS: Anthracyclines disrupt LA-LV coordination in pediatric leukemia, with higher doses exacerbating atrial strain impairment. These findings highlight CMR-derived strain parameters as critical for monitoring anthracycline-induced cardiac impairment.