Guan Feng, Zhao Hongguang, Jiao Benzheng, Liu Shanshan, Sa Ri, Hou Sen, Lin Qiuyu, Wang Qi, Lin Chenghe
Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China.
Department of Hematology and Oncology, First Hospital of Jilin University, Changchun, China.
Ann Nucl Med. 2016 Feb;30(2):138-44. doi: 10.1007/s12149-015-1046-7. Epub 2015 Dec 21.
The common form and risk factors of electrocardiogram (ECG) abnormality in thyroidectomized differentiated thyroid carcinoma (DTC) patients with short-term overt hypothyroidism were investigated and some discriminant formulas for forecasting the occurrence of abnormal ECG in this specific population were deduced in this study.
A total of 260 thyroidectomized DTC patients were retrospectively reviewed, 67 of whom had abnormal ECG and 193 normal ECG after short-term (3 weeks) levothyroxine (L-T4) withdrawal. One-way ANOVA, Spearman's rank correlation analysis and discriminant function analysis were performed using data from these DTC patients.
A flat or inverted T wave in inferior myocardial and left ventricular wall leads was the most common abnormal ECG finding in short-term overt hypothyroidism. Statistical analyses showed that age, interval, TSH-end (The serum hormothyrin level at the end of L-T4 withdrawal for 3 weeks), and TSH-vel (The average ascending velocity of serum hormothyrin level during L-T4 withdrawal for 3 weeks) were statistically significant and positively correlated with the occurrence of abnormal ECG. Meanwhile, TSH-vel showed the highest correlation coefficient (r = 0.358, p = 0.000). The formulas, especially deduced from age, interval and TSH-vel, could discriminate patients with abnormal ECG or not as high as 77.6 and 70.5%, respectively (resubstitution accuracy: 72.3%).
The thyroidectomized DTC patients undergoing short-term L-T4 withdrawal before their first radioiodine ablative therapy, who had one or more of the above-mentioned risk factors, are likely to show abnormal ECG findings. The formulas from discriminant function analysis may be helpful for predicting patients with abnormal ECG with short-term L-T4 withdrawal and allow appropriate medical intervention beforehand.
本研究调查了短期明显甲状腺功能减退的甲状腺切除术后分化型甲状腺癌（DTC）患者心电图（ECG）异常的常见形式和危险因素，并推导了一些用于预测该特定人群ECG异常发生的判别公式。
回顾性分析了260例甲状腺切除术后的DTC患者，其中67例在短期（3周）停用左甲状腺素（L-T4）后心电图异常，193例心电图正常。对这些DTC患者的数据进行单因素方差分析、Spearman等级相关分析和判别函数分析。
下壁心肌和左心室壁导联T波低平或倒置是短期明显甲状腺功能减退时最常见的心电图异常表现。统计分析表明，年龄、停药时间、停药3周时的促甲状腺激素（TSH）水平（L-T4停药结束时的血清促甲状腺激素水平）和TSH上升速度（L-T4停药3周期间血清促甲状腺激素水平的平均上升速度）与心电图异常的发生具有统计学意义的正相关。同时，TSH上升速度的相关系数最高（r = 0.358，p = 0.000）。由年龄、停药时间和TSH上升速度推导的公式分别能以高达77.6%和70.5%的准确率区分心电图异常患者（交叉验证准确率：72.3%）。
首次放射性碘消融治疗前短期停用L-T4的甲状腺切除术后DTC患者，若存在上述一种或多种危险因素，则可能出现心电图异常表现。判别函数分析得出的公式可能有助于预测短期停用L-T4的心电图异常患者，并允许提前进行适当的医疗干预。
