title: Discriminant function analysis of the occurrence risk of abnormal electrocardiogram in thyroidectomized differentiated thyroid carcinoma patients with short-term overt hypothyroidism.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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%).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. guanfengnm@163.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Guan
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. zhaohg@jlu.edu.cn.
authors.forename: Hongguang
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. jiaobz8888@163.com.
authors.forename: Benzheng
authors.initials: B
authors.lastname: Jiao
authors.affiliation: Department of Hematology and Oncology, First Hospital of Jilin University, Changchun, China. liushanshan8888@gmail.com.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. Sarihoo012@163.com.
authors.forename: Ri
authors.initials: R
authors.lastname: Sa
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. hou_sen@jlu.edu.cn.
authors.forename: Sen
authors.initials: S
authors.lastname: Hou
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. toothsandy@live.cn.
authors.forename: Qiuyu
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. wangqi5555@163.com.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Nuclear Medicine, First Hospital of Jilin University, Changchun, China. linchh1967@163.com.
authors.forename: Chenghe
authors.initials: C
authors.lastname: Lin
mesh_terms: D000328:Adult; D016002:Discriminant Analysis; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy; D055815:Young Adult
keywords: Differentiated thyroid carcinoma; Discriminant analysis; Electrocardiogram; Short-term overt hypothyroidism