- 期刊
Changes of Cardiac Functions in Athyreotic Patients with and without Suppressive Thyroxine Treatment
抑制性甲狀腺素治療對無甲狀腺病人之心臟功能影響
摘要
目的：甲狀腺激素會影響心臟功能。報告指出長期使用甲狀腺素(T4)治療病人可能出現心臟肥大現象，主要是與心舒張功能異常有關。本研究乃針對接受抑制性甲狀腺素治療(suppressive thyroxine therapy; STT)的無甲狀腺病人在接受抑制性甲狀腺素治療以及停用抑制性甲狀腺素4週時，以核醫心臟功能檢查觀察此治療對其心臟功能的影響。 方法：共有43位因分化型甲狀腺癌術後並接受碘－131治療及抑制性甲狀腺素治療之無甲狀腺病人為觀察重點（平均年齡42±9歲，範圍為25至56歲）。以核醫心臟功能造影評估接受抑制性甲狀腺素治療時（甲狀腺素4-5微克／公斤／天，6-12個月，平均9個月）及停藥4週後之左心室射出分率(LVEF)、尖峰填充率(PFR)及尖峰射出率(PER)數值變化。病人同時接受抽血檢查分析其甲狀腺功能，包括T3、T4、促甲狀腺素(TSH)及游離T4，並觀察心臟功能參數變化與甲狀腺功能之相關性。 結果：血液甲狀腺功能檢查顯示病人在接受抑制性甲狀腺素治療時呈現亞臨床甲狀腺功能過高，停藥時則呈甲狀腺功能低下。其中在治療時的尖峰填充率及休息心率(resting heart rate)比較停藥時呈有意義增加（3.18±0.06 vs. 2.91±0.06 EDV/sec, 以及82±10 vs. 72±11 beats/min, P值分別爲＜0.05以及＜0.01），而左心室射出分率及尖峰射出率則無顯著統計差異。另發現於停藥時的尖峰填充率與血中TSH值呈稍弱但有意義的負相關性(P=0.045)。 結論：本研究結果似乎顯示無甲狀腺病人服用抑制性甲狀腺素與否可能會影響左心室舒張功能，其長期效應特別是對年老者及已有心臟病病人仍需進一步評估。
並列摘要
Objectives: Thyroid hormone (TH) exerts profound effects on the heart. The presence of cardiac hypertrophy in patients receiving long term L-T4 therapy is associated with a marked diastolic dysfunction. The study was performed to investigate the possible effect of suppressive thyroxine treatment (STT) on cardiac functions in athyreotic patients. Methods: Forty-three athyreotic patients (mean age 42 ± 9 years old, and range from 25 to 56 years old) who received STT to suppress thyrotropin synthesis after surgery and 131I ablation for differentiated thyroid carcinoma were studied. Scintigraphic evaluation of cardiac functions including left ventricle (LV) ejection fraction (EF), peak filling rate (PFR) and peak ejection rate (PER) was performed during STT [Eltroxin (T4), 4-5 pg/kg/day for 6-12 (mean, 9) months] and 4 weeks after discontinuing treatment. The concomitant blood samples were drawn and were analyzed simultaneously for concentrations of serum TH including T3, T4, TSH and free T4. Results: The thyroid profiles showed that patients were subclinically hyperthyroid with STT and hypothyroid 4 wk after STT withdrawal. The values of PFR and resting heart rate were significantly increased in the STT group as compared to that of T4 withdrawal (3.18±0.06 vs. 2.91 ±0.06 EDV/sec and 82 ± 10 vs. 72 ± 11 beats/mm, P＜0.05 and P＜0.01, respectively). However, no significant changes of mean EF and PER values were found. There were weekly significant negative correlations between PFR and serum TSH values in the STT withdrawal group (P= 0.045). Conclusion: Our results support the view that LV diastolic function may be affected in athyreotic patients with thyroidal dysfunction. However, its long-term effect, especially to the aged and with preexisting cardiovascular disorders patients, needs further clarified.