Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Queen Mary Hospital, 102, Pokfulam Road, Hong Kong, China.
Eur Heart J Cardiovasc Imaging. 2013 Feb;14(2):175-82. doi: 10.1093/ehjci/jes143. Epub 2012 Jul 15.
Subendocardial layer of the ventricle has been shown to be sensitive to anthracycline damage. This study tested the hypothesis that anthracycline therapy for childhood malignancies has differential impact on deformation and rotation of left ventricular (LV) subendocardial and subepicardial layers and hence transmural myocardial strain and rotation gradients.
Thirty-two anthracycline-treated survivors of childhood malignancies aged 19.3 ± 5.4 years and 28 controls were studied. Apical four-chamber and parasternal LV short-axis acquisitions at base, papillary muscle level, and apex were analysed for layer-specific myocardial strain and apical and basal rotation and rotational velocities using two-dimensional speckle tracking echocardiography. Transmural strain and rotation gradients were calculated as differences between peak systolic strain and rotation between the inner and outer layers, respectively. Compared with controls, patients had significantly lower transmural circumferential, but not radial or longitudinal, strain gradients (P< 0.05), accounted by the reduced subendocardial circumferential strain, at all three ventricular levels (all P< 0.05). No significant difference in basal transmural rotation gradient was found between patients and controls (P= 0.32). On the other hand, apical rotation, systolic twisting velocity, and diastolic untwisting velocity were reduced preferentially at the subendocardial layer in patients (all P< 0.05), hence accounting for their significantly reduced transmural rotation gradient compared with controls (P< 0.001). The LV ejection fraction correlated inversely with apical transmural circumferential strain gradient (r= -0.39, P= 0.002) and rotation gradient (r= 0.33, P= 0.01).
Preferential impairment of subendocardial circumferential deformation and apical rotation with consequential reduction of transmural circumferential strain and rotation gradients occurs in anthracycline-treated survivors of childhood cancers.
已证实心室的心肌内层对蒽环类药物损伤较为敏感。本研究旨在验证假设，即蒽环类药物治疗儿童恶性肿瘤对左心室（LV）心肌内层和外层的变形和旋转，以及心肌整体应变和旋转梯度有不同的影响。
研究纳入了 32 名接受蒽环类药物治疗的儿童恶性肿瘤幸存者（年龄 19.3 ± 5.4 岁）和 28 名对照者。采用二维斑点追踪超声心动图分析心尖四腔心和胸骨旁左室短轴在基底、乳头肌水平和心尖的层特异性心肌应变以及心尖和基底旋转和旋转速度。通过计算内层和外层之间的峰值收缩应变和旋转之间的差异，来计算心肌整体应变和旋转梯度。与对照组相比，患者的心肌整体环向应变梯度显著降低（P<0.05），但径向和纵向应变梯度没有差异（P>0.05），这主要是由于各心室水平的内层心肌环向应变降低所致（均 P<0.05）。患者与对照组之间的基底心肌整体旋转梯度无显著差异（P=0.32）。另一方面，患者的心尖旋转、收缩扭转速度和舒张解旋速度主要在内层心肌中降低（均 P<0.05），因此与对照组相比，患者的心肌整体旋转梯度显著降低（P<0.001）。左心室射血分数与心尖层心肌整体环向应变梯度（r=-0.39，P=0.002）和旋转梯度（r=-0.33，P=0.01）呈负相关。
在接受蒽环类药物治疗的儿童癌症幸存者中，心肌内层的环向变形和心尖旋转首先受损，继而导致心肌整体环向应变和旋转梯度降低。
