Background

Anthracycline cardiotoxicity can cause significant long-term morbidity in childhood cancer survivors (CCS), but many CCS do not manifest clinical symptoms until adulthood. The aims of this study were to characterize the dynamic myocardial response to exercise of CCS at long-term follow-up by combining semisupine bicycle exercise stress echocardiography with myocardial imaging techniques and to establish whether semisupine bicycle exercise stress echocardiography could identify CCS with abnormal exercise response.

Methods

This was a single-center prospective cross-sectional study. One hundred CCS and 51 control subjects underwent semisupine bicycle exercise stress echocardiography. Color Doppler tissue imaging peak systolic (s′) and diastolic (e′) velocities, myocardial acceleration during isovolumic contraction, and longitudinal strain were measured at rest and at incremental heart rates in the left ventricular (LV) lateral wall, basal septum, and right ventricle. The relationship with increasing heart rate was evaluated for each parameter by plotting the values against heart rate at each stage of exercise. Kernel density estimate was used to establish the normality of the individual CCS exercise responses.

Results

At rest, no significant differences were found for LV lateral wall, right ventricular (RV), and basal septal systolic and diastolic velocities between CCS and control subjects. Only septal e′ was lower in CCS. LV longitudinal strain was similar between groups, while RV longitudinal strain was lower in CCS. At peak exercise, LV lateral wall, RV, and septal s′ were not different between groups, while e′ were significantly lower in CCS. LV lateral wall and septal isovolumic acceleration were also reduced in CCS. LV longitudinal strain was different between groups, while RV longitudinal strain was similar. The dynamic response of Doppler tissue imaging velocities, isovolumic acceleration, and strain was similar between CCS and control subjects. Kernel density estimate analysis confirmed that most CCS responses were within the normal range.

Conclusions

At 10-year follow-up, anthracycline-treated CCS with normal baseline ejection fractions have LV and RV systolic and diastolic myocardial exercise response comparable with that of control subjects. Minor differences were observed between CCS and control subjects at rest and at peak exercise, but the dynamic response is within the normal range.

中文翻译：

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蒽环类药物治疗的儿童癌症幸存者对运动的动态心肌反应

背景

蒽环类药物的心脏毒性可导致儿童癌症幸存者（CCS）的大量长期发病，但许多CCS直到成年才表现出临床症状。这项研究的目的是通过将半仰卧位自行车运动压力超声心动图与心肌成像技术相结合，以表征长期随访中CCS运动的动态心肌反应，并确定半仰卧位自行车运动压力超声心动图是否可以识别出运动异常的CCS。 。

方法

这是一项单中心前瞻性横断面研究。一百名CCS和51名对照受试者接受了半仰卧位自行车运动负荷超声心动图检查。在静止和以递增的心率测量左室侧壁（LV）侧壁，基底间隔和左室（LV）的彩色多普勒组织成像的峰值收缩压（s'）和舒张压（e'）速度，等容收缩过程中的心肌加速度和纵向应变右心室。通过在运动的每个阶段针对心率绘制值来评估每个参数与心率增加的关系。内核密度估计用于确定各个CCS运动响应的正态性。

结果

静息时，CCS与对照组之间的LV侧壁，右心室（RV）以及基底间隔收缩和舒张速度没有显着差异。在CCS中只有中隔e'较低。组间LV纵向应变相似，而CCS中RV纵向应变较低。在高峰运动时，两组的LV侧壁，RV和间隔s'没有差异，而在CCS中e'明显较低。在CCS中，LV侧壁和间隔等容加速也降低了。两组之间的LV纵向应变不同，而RV纵向应变相似。CCS和对照组之间的多普勒组织成像速度，等容加速和应变的动态响应相似。内核密度估算分析证实，大多数CCS响应均在正常范围内。

结论

在10年的随访中，蒽环类药物治疗的CCS具有正常的基线射血分数，其LV和RV收缩期和舒张期心肌运动反应与对照组相当。在静息状态和运动高峰时，CCS和对照组之间观察到微小差异，但动态响应在正常范围内。