Abstract 18153: Abnormal Dynamic Myocardial Response to Exercise Despite Normal Resting Ejection Fraction in Childhood Cancer Survivors Treated With Anthracyclines
Introduction: There are limited data on myocardial systolic & diastolic response to exercise in pediatric cancer survivors treated with anthracycline. We used exercise echocardiography to evaluate ventricular systolic and diastolic reserve in these patients.
Methods: 50 children (age 14.4±2.4 years) who had received anthracycline treatment with median dose 178mg/m2 (range 60-450) underwent stepwise exercise echocardiography at 9.3±2.9 years after end of therapy, and compared with 50 normal controls. All subjects had normal resting LVEF. Peak systolic (s’) & early diastolic (e’) myocardial velocities in the LV & RV lateral wall, & basal septum were measured at rest & during exercise using color TDI. Measurements of myocardial isovolumic acceleration (IVA) at incremental heart rates (HR) were used to study force-frequency relationships (FFR).
Results: At rest, LV systolic parameters were preserved in patients; septal e’ was significantly lower compared to controls (10.4±1.9cm/s vs 11.4±1.9cm/s; p=0.009). At peak exercise, LV & RV lateral wall, & basal septal e’ velocities were lower in patients (17.4±3.8cm/s vs 19.6±3.1cm/s, p=0.002; 21.5±1.6cm/s vs 22.3±1.9cm/s, p=0.02; & 16.3±2.4cm/s vs 18.7±2.7cm/s, p<0.001; respectively) & the slopes of change with increasing HR were significantly lower in patients for LV lateral e’ [EST (SE): +0.68 (0.08) vs +0.85 (0.05) cm/s per 10 bpm; p<0.001], RV lateral e’ [+1.47 (0.05) vs 1.69 (0.06) cm/s per 10 bpm; p<0.001] & basal septum e’ [+0.50 (0.05) vs 0.58 (0.05) cm/s per 10 bpm; p=0.001]. During exercise, peak contractile force developed by patients was significantly lower (LV IVA 5.12±1.85m/s2 vs 6.75±3.28m/s2; p=0.004). FFR analysis showed reduced rate-contractility trajectory in patients [+0.202 (0.008) vs +0.217 (0.008) natural log m/s2 per 10 bpm; p=0.001].
Conclusions: Long-term survivors of anthracycline-treated pediatric cancer have reduced systolic & diastolic myocardial reserve in response to exercise.
Author Disclosures: C.-. Chen: None. B. Cifra: None. C. Slorach: None. C. Manlhiot: None. B.W. McCrindle: None. A. Dragulescu: None. M.K. Friedberg: None. A.N. Redington: None. P.C. Nathan: None. L. Mertens: None.
- © 2014 by American Heart Association, Inc.