METHODS: Fifty BC patients underwent TTE assessment before and three months after chemotherapy. HRV indexes were obtained from continuous electrocardiograms in supine position with spontaneous breathing, active standing, and supine position with controlled breathing. The magnitude of change (Δ) between supine-standing and supine-controlled breathing was calculated. Variables were compared using t-test or ANOVA. Cardiotoxicity predictive value was assessed by ROC curve analysis. A p value of < 0.05 was considered significant.
RESULTS: TTE revealed reduced left atrial conduit strain in the cardiotoxicity group. Mean heart rate increased during all maneuvers at follow-up, with no differences in HRV indexes between patients with or without cardiotoxicity. However, a lower Δ in supine-controlled breathing of several HRV indexes predicted early cardiotoxicity identified by echocardiography (e.g. SDNN ≤ -8.44 ms: Sensitivity = 75%, Specificity = 69%).
CONCLUSIONS: BC patients treated with chemotherapy maintain cardiac autonomic responses to physiological stimuli after 3 months of chemotherapy. However, a lower Δ during active standing and controlled breathing before chemotherapy may predict early cardiotoxicity.
方法:50例BC患者在化疗前和化疗后3个月进行TTE评估。从仰卧位自主呼吸的连续心电图获得HRV指标,积极站立,仰卧位控制呼吸.计算仰卧站立和仰卧控制呼吸之间的变化幅度(Δ)。使用t检验或ANOVA比较变量。通过ROC曲线分析评估心脏毒性的预测价值。<0.05的p值被认为是显著的。
结果:TTE显示心脏毒性组左心房导管劳损降低。在随访的所有动作中,平均心率增加,在有或没有心脏毒性的患者之间,HRV指数没有差异。然而,仰卧控制呼吸中若干HRV指数的较低Δ预测通过超声心动图识别的早期心脏毒性(例如,SDNN≤-8.44ms:灵敏度=75%,特异性=69%)。
结论:接受化疗的BC患者在化疗3个月后对生理刺激保持心脏自主神经反应。然而,化疗前主动站立和控制呼吸期间较低的Δ可以预测早期心脏毒性。