Evaluation of Cardiac Electrophysiological Balance in Patients with Subclinical Hypothyroidism

Authors : Faysal ŞAYLIK, Tufan ÇINAR, Murat SELÇUK, Tayyar AKBULUT

Pages : 77-84

View : 18 | Download : 9

Publication Date : 2022-04-18

Article Type : Research Paper

Abstract :Introduction: Subclinical hypothyroidism insert ignore into journalissuearticles values(SH); is defined by slightly elevated thyroid-stimulating hormone insert ignore into journalissuearticles values(TSH); levels with normal free triiodothyronine insert ignore into journalissuearticles values(fT3); and thyroxine insert ignore into journalissuearticles values(fT4); levels. SH is related to cardiovascular events, including malignant arrhythmias. Cardiac electrophysiological balance insert ignore into journalissuearticles values(iCEB); and its corrected form with heart rate insert ignore into journalissuearticles values(iCEBc); are useful electrocardiographic insert ignore into journalissuearticles values(ECG); parameters for the prediction of malign arrhythmias. In this study, we aimed to evaluate iCEB and iCEBc in SH patients. Patients and Methods: A total of 164 patients insert ignore into journalissuearticles values(n= 82 patients with SH and n= 82 controls); were enrolled in this study. iCEB was calculated by dividing QT by QRS, and iCEBc was calculated by dividing corrected QT insert ignore into journalissuearticles values(QTc); by QRS. The groups were compared based on ECG parameters. Correlation and multiple linear regression analyses were used to assess the association of ECG parameters with TSH levels. Results: There were no differences between the groups regarding clinical and laboratory findings. Tp-e, QT, QTc, Tp-e/QT, Tp-e/QTc, iCEB, and iCEBc were significantly prolonged in SH patients compared to controls. In correlation analyses, all of the abovementioned ECG parameters were significantly correlated with serum TSH levels. Multiple linear regression analysis indicated that Tp-e, iCEB, and iCEBc were independently associated with serum TSH levels in SH patients. Conclusion: To our knowledge, this was the first study to demonstrate that iCEB and iCEBc were both prolonged in SH patients compared to controls, and both of them were independently correlated with TSH levels in such patients.
Keywords : Hypothyroidism, cardiac electrophysiology, cardiac arrhythmia