Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China.
Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, Hubei, China; Hubei Key Laboratory of Cardiology, Wuhan 430060, Hubei, China.
Auton Neurosci. 2018 Sep;213:86-91. doi: 10.1016/j.autneu.2018.06.006. Epub 2018 Jun 28.
To investigate the effects of thyroid hormones on cardiac autonomic nervous activity and ventricular repolarization dynamicity in hyperthyroidism.
57 consecutive patients first diagnosed of hyperthyroidism (HT group) and 55 age and sex-matched healthy volunteers (Control group) from March 2012 to March 2013 in our center were enrolled. All subjects underwent standard 12‑lead ECG and 24 h Holter recording at baseline. For the HT group, free triiodothyronine (FT), free thyroxine (FT) and thyroid stimulating hormone (TSH) were monitored, and after they returned to normal all the examinations were redone. Heart rate variability (HRV) was assessed to determine the cardiac autonomic nervous activity. QTe/RR slope (QT end) and QTp/RR slope (QT apex) were calculated to evaluate the ventricular repolarization dynamicity.
The HT patients before treatment had significantly higher LF/HF, QTe/RR slope and QTp/RR slope, and larger QT dispersion than the controls and after treatment (P < 0.05 for all). Correlation analyses revealed that FT was positively correlated with QTe/RR and QTp/RR slopes (r = 0.689 and 0.665 respectively, P < 0.001 for both), and similarly in FT (r = 0.665 and 0.668 respectively, P < 0.001 for both). While TSH was negatively correlated with QTe/RR and QTp/RR slopes (r = -0.660 and -0.680 respectively, P < 0.001 for both). FT and FT levels were independent predictors of QTe/RR slopes (P < 0.001, β = 0.007; P = 0.017, β = 0.001, respectively) and QTp/RR slopes (P < 0.001, β = 0.008; P = 0.002, β = 0.001, respectively).
High-level thyroid hormones induce the cardiac sympathetic overactivity and increases ventricular repolarization dynamicity, and the impact can be attenuated after euthyroidism restored.
探讨甲状腺激素对甲状腺功能亢进症患者心脏自主神经活性和心室复极动力学的影响。
选择 2012 年 3 月至 2013 年 3 月在我院就诊的 57 例首次诊断为甲状腺功能亢进症（HT 组）的连续患者和 55 例年龄和性别匹配的健康志愿者（对照组）。所有患者在基线时均进行标准 12 导联心电图和 24 h 动态心电图检查。对 HT 组患者，监测游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）和促甲状腺激素（TSH）水平，当甲状腺功能恢复正常后，重新进行所有检查。评估心率变异性（HRV）以确定心脏自主神经活性。计算 QT 间期/心率（QTc）斜率（QTc 末端）和 QT 峰值/心率（QTp）斜率（QTp 顶点）以评估心室复极动力学。
治疗前 HT 患者的 LF/HF、QTc/RR 斜率和 QTp/RR 斜率明显高于对照组，QT 离散度也明显高于对照组（均 P<0.05）。相关性分析显示，FT3 与 QTc/RR 和 QTp/RR 斜率呈正相关（r 值分别为 0.689 和 0.665，均 P<0.001），FT4 与 QTc/RR 和 QTp/RR 斜率也呈正相关（r 值分别为 0.665 和 0.668，均 P<0.001）。而 TSH 与 QTc/RR 和 QTp/RR 斜率呈负相关（r 值分别为-0.660 和-0.680，均 P<0.001）。FT3 和 FT4 水平是 QTc/RR 斜率（P<0.001，β=0.007；P=0.017，β=0.001）和 QTp/RR 斜率（P<0.001，β=0.008；P=0.002，β=0.001）的独立预测因子。
高水平甲状腺激素可引起心脏交感神经活性过度增强，增加心室复极动力学，甲状腺功能正常后这种影响可减弱。
