Analysis Of Correlation Between Thyroid Hormone/Thyroid-Related Antibodies And ECG In Patients With Graves’ Disease

Objective: Hyperthyroidism is commonly seen nowadays, and hyperthyroidism-related heart damage is a major complication of hyperthyroidism, which is called hyperthyroid heart disease, HHD. Clinical manifestations of HHD are sinus tachycardia, atrial fibrillation, heart enlargement, hear failure, and even death in severe cases. Since the heart is the main target organ of thyroid-related diseases, and heart damage usually lead to increased risk of diseases, hyperthyroid heart disease has been gradually recognized. The main cause of hyperthyroidism due to Graves’ disease, which accounted for 80 percent, and heart damage caused by GD also accounted for the majority of HHD. Recent researches show that these heart abnormalities are not only caused by thyroid hormone(TH), but also may be associated with autoimmune thyroid disease(AITD) related antibodies. This research aim to investigate the characteristics of ECG of GD patients, and evaluate the relationship among TH levels, AITD related antibodies and ECG manifestations, therefore explore the possible mechanism of GD-related heart disease.Method: A total of 412 cases form January 2014 to July 2015 in Cangzhou People’s Hospital outpatient and inpatient departments were collected, which were all initially diagnosed as GD. Diagnostic criteria: the diagnostic criteria of GD from Medicine, the eighth edition of the People’s Health Publishing House. Seventy five patients with newly diagnosed GD were concluded after screening(male 14, female 61). Serum total thyroxine(TH), total three triiodothyronine(TT3), serum free thyroxine(FT4), three free triiodothyronine(FT3), thyroid stimulating hormone(TSH), thyroid peroxidase antibody(TPOAb), TSH receptor antibody(TRAb), thyroglobulin antibody(TGAb) were measured by electrochemical luminescence method. Electrocardiogram was also conducted in each patient. SPSS 19 software was used for statistical analysis. Results:1. Among the patients, ECG abnormalities were observed in 42 cases(56.0%). The main changes in ECG were: sinus tachycardia 30 cases(40.0%), 5 atrial fibrillation(6.0%), 3 atrial premature beats(4.0%), 2 ventricular premature beats(2.7%), 2 ST-T change(2.7%), 1 complete left bundle branch block(1.3%), 1 left atrial abnormalities(1.3%). And in some cases, more than two kinds of changes in ECG were observed.2. The rates of ECG abnormalities were not statistically different among ages or genders(P>0.05).3. The levels of FT3 were statistically different among heart rates, P wave duration, P-R interval and QT period time(P<0.05), while they were not statistically different among QRS duration or QTC duration(P>0.05).4. The levels of FT4 were statistically different among heart rates, P wave duration and QT period time(P<0.05), while they were not statistically different among QT period time, QRS duration or QTC duration(P>0.05).5. The levels of TRAb were statistically different among P wave duration and P-R interval time(P<0.05), while they were not statistically different among heart rates, QT period time, QRS duration or QTC duration(P>0.05).6. The levels of TPOAb were not statistically different among heart rates, P wave duration, P-R interval time, QT period time, QRS duration or QTC duration(P>0.05).7. The levels of TGAb were not statistically different among heart rates, P wave duration, P-R interval time, QT period time, QRS duration or QTC duration(P>0.05).8. Multiple regression analysis showed that the levels of FT3 were positively related to heart rates significantly(r =0.570,p=0.010), the levels of TRAb were negatively related to P wave duration significantly(r=-0.368,p=0.002), and the levels of TRAb were negatively related to P-R interval time significantly(r=-0.356,p=0.002).Conclusion:1. The incidences of HHD in patients with newly diagnosed GD is not related to genders or ages of the patients.2. The analysis of ECG with these patients shows that the levels of FT3 are positively related to heart rates significantly.3. Among the AITD-related antibodies, only the levels of TRAb are negatively related to P wave duration and P-R interval time.4. The levels of TPOAb and TGAb are not related to heart rates, P wave duration, P-R interval time, QRS duration, QTC duration or QT period time.