title: Left ventricular twisting and untwisting motion in childhood cancer survivors.
abstract: BACKGROUND
  Anthracycline has been shown to degrade titin that plays a role in myocardial twisting and untwisting. This study aimed to test the hypothesis that left ventricular (LV) twisting and untwisting motion may be altered in children after anthracycline therapy.
  
  
  METHODS
  Thirty-six childhood leukemia survivors aged 15.6 ± 5.5 years and 20 healthy controls aged 16.8 ± 7.7 years (P = 0.54) were studied. LV twisting and untwisting motion was determined using speckle tracking imaging, whereas LV ejection fraction and systolic and diastolic mitral annular velocities were determined respectively by three-dimensional and tissue-Doppler echocardiography.
  
  
  RESULTS
  Compared with controls, patients had significantly lower LV ejection fraction (P = 0.01) but similar systolic and diastolic mitral annular velocities (all P > 0.05). Their peak LV torsion (P = 0.003), systolic twisting velocity (P < 0.001), and diastolic untwisting velocity (P = 0.04) were significantly lower than controls, which could be attributable to their reduced apical rotation (P = 0.03) and apical untwisting rate (P = 0.002). For the whole cohort, LV systolic torsion and twisting velocity correlated significantly with apical untwisting rate (P < 0.001) and LV diastolic untwisting velocity (P < 0.001). In patients, none of the twisting or untwisting parameters were found to correlate with cumulative anthracycline dose (all P > 0.05). Twenty-eight (78%) patients had LV ejection fractions ≥50%. Although their systolic and diastolic mitral annular velocities were similar to those of controls, their peak LV torsion (P = 0.005), apical untwisting rate (P = 0.01), and LV systolic twisting velocity (P = 0.001) remained significantly lower.
  
  
  CONCLUSIONS
  Impairment of LV twisting and untwisting motion is evident in children after anthracycline therapy, even in those with "normal" LV ejection fractions.
authors: Department of Pediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China. xfcheung@hkucc.hku.hk
authors: Yiu-fai
authors: YF
authors: Cheung
authors: Shu-na
authors: SN
authors: Li
authors: Godfrey C F
authors: GC
authors: Chan
authors: Sophia J
authors: SJ
authors: Wong
authors: Shau-yin
authors: SY
authors: Ha