Left ventricular myocardial deformation and mechanical dyssynchrony in children with normal ventricular shortening fraction after anthracycline therapy.
OBJECTIVE
The M-mode-derived left ventricular shortening fraction is incorporated into most of the paediatric oncology protocols for monitoring of cardiotoxicity. This study tested the hypothesis that alteration of left ventricular myocardial deformation and mechanical dyssynchrony may occur in asymptomatic children after anthracycline therapy despite having left ventricular shortening fractions within the limits of normal.


METHODS
Cross-sectional study.


METHODS
Tertiary paediatric cardiac centre.


METHODS
Left ventricular longitudinal, circumferential and radial myocardial deformation was determined using speckle tracking echocardiography in 45 patients aged 15.3+/-5.8 years. Real-time three-dimensional echocardiographic data were acquired for the measurement of left ventricular volumes and systolic dyssynchrony index (SDI), the latter derived from the dispersion of time-to-minimum regional volume using a 16-segment model. The results were compared with those of 44 controls.


RESULTS
Compared with controls, patients had reduced left ventricular global systolic longitudinal strain (p=0.012), circumferential strain (p<0.001), radial strain (p=0.006) and circumferential strain rate (SR; p=0.002). The cumulative anthracycline dose correlated negatively with global longitudinal (r=-0.33, p=0.027) and circumferential (r=-0.32, p=0.035) SR. The left ventricular SDI was significantly greater in patients than controls (4.46+/-1.52% vs 3.80+/-0.58%, p=0.03). The prevalence of left ventricular mechanical dyssynchrony (SDI >4.96%) in patients was 16% (95% CI 6% to 29%). In patients, SDI correlated negatively with left ventricular ejection fraction (r=-0.52, p<0.001), radial strain (r=-0.35, p=0.021), circumferential strain (r=-0.37, p=0.015) and circumferential SR (r=-0.43, p=0.004), but not with the cumulative anthracycline dose (p=0.82).


CONCLUSIONS
Impaired left ventricular myocardial deformation and mechanical dyssynchrony may exist in children after anthracycline therapy despite having normal left ventricular shortening fractions.
Cheung
Yiu-fai
YF
Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China. xfcheung@hkucc.hku.hk
Hong
Wen-jing
WJ
Chan
Godfrey C F
GC
Wong
Sophia J
SJ
Ha
Shau-yin
SY
D000293:Adolescent; D018943:Anthracyclines / Q000009:adverse effects*; D000903:Antibiotics, Antineoplastic / Q000009:adverse effects* / Q000627:therapeutic use; D016022:Case-Control Studies; D002648:Child; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler / Q000379:methods; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000187:drug effects; D055815:Young Adult
D018943:Anthracyclines; D000903:Antibiotics, Antineoplastic