Effect of Levothyroxine Replacement Therapy on Improving Diffused Left Ventricular Myocardial Lesions in Patients With Hypothyroidism / 中国循环杂志

ABSTRACT

Objective: To study the effect of levothyroxine replacement therapy on improving diffused left ventricular myocardial lesions and cardiac function in patients with hypothyroidism. Methods: Our research included 2 groups Hypothyroidism group,n=20 newly diagnosed patients and Control group, n=17 normal healthy subjects. Diffused left ventricular myocardial lesions were quantitatively evaluated by non-invasive cardiac MRI T1 mapping technique. Left ventricular myocardial T1 value and left ventricular function before and after levothyroxine replacement therapy were compared; the relationship between T1 value and thyroid function and the relationship between T1 value and the indicators of left ventricular function were analyzed. Results:①Compared with Control group, Hypothyroidism group had increased left ventricular myocardial T1 value, P<0.01, while decreased cardiac index (CI) and left ventricular peak filling rate (PFR), allP<0.05.②In patients with hypothyroidism, left ventricular myocardial T1 value was negatively related to serum FT3 level (r=-0.52,P=0.0006) and PFR (r=-0.43,P=0.0085).③Compared with pre-therapeutic condition, the patients with recovered normal thyroid function showed obviously decreased left ventricular myocardial T1 value and improved CI, PFR. Conclusion: Levothyroxine replacement therapy may improve diffused left ventricular myocardial lesions in patients with hypothyroidism, and therefore improve the cardiac function.