Department of Experimental and Applied Medicine, University of Brescia, Italy.
J Investig Med. 2012 Aug;60(6):907-10. doi: 10.2310/JIM.0b013e31825cec9c.
Low-triiodothyronine syndrome (LT3S) is a condition characterized by decreased total serum T3 and free T3 (fT3) with normal levels of thyroxine (fT4) and thyrotropin (TSH). Experimental studies have shown that altered thyroid hormones (THs) metabolism modifies cardiovascular homeostasis. The aim of the study was to evaluate prospectively the reversibility and pathophysiological implications of sick euthyroid syndrome in patients with moderate-to-severe chronic heart failure. This study should demonstrate the role of short-term acute dobutamine heart failure (HF) treatment in improving thyroid hormone, neuroendocrine profile, and ventricular performance in patients with worsening HF and LT3S.
During hospitalization for worsening heart failure, fT3, fT4, and TSH levels; brain natriuretic peptide; and echocardiographic and right hemodynamic parameters were recorded on admission, after HF treatment and after dobutamine infusion in patients with LT3S.
We evaluated 60 patients hospitalized for severe acute decompensated HF. Fourteen patients (23%) of the population presented an LT3S. Dobutamine infusion in LT3S patient group evoked a statistically significant cardiac index increase, pulmonary capillary arterial wedge pressure, and right atrial pressure decrease with left ventricle diastolic dysfunction recovery; the hemodynamic and clinical improvement were associated with brain natriuretic peptide reduction and increased fT3 levels. Free T3 levels increased in all of them and normalized in 6 patients (42%). Free T4 and TSH values remained unchanged.
These data suggest that LT3S in patients with acute decompensated HF can be useful in assessing the status and clinical course for this disease. These preliminary results indicate that LT3S reversibility by dobutamine is associated with short-term hemodynamic and neurohormonal improvement in patients with persistent severe heart failure.
低三碘甲状腺原氨酸综合征（LT3S）的特征是总血清 T3 和游离 T3（fT3）降低，而甲状腺素（fT4）和促甲状腺素（TSH）水平正常。实验研究表明，甲状腺激素（THs）代谢的改变会影响心血管稳态。本研究旨在前瞻性评估中度至重度慢性心力衰竭患者病态甲状腺功能正常综合征的可逆性和病理生理学意义。该研究应证明短期急性多巴酚丁胺心力衰竭（HF）治疗在改善甲状腺激素、神经内分泌谱和心室功能方面的作用，改善恶化的 HF 和 LT3S 患者的病情。
在因心力衰竭恶化而住院期间，在 LT3S 患者入院时、HF 治疗后和多巴酚丁胺输注后记录游离 T3、游离 T4 和 TSH 水平、脑钠肽以及超声心动图和右心血流动力学参数。
我们评估了 60 例因严重急性失代偿性 HF 住院的患者。在人群中，有 14 名患者（23%）患有 LT3S。在 LT3S 患者组中，多巴酚丁胺输注引起心指数增加、肺毛细血管楔压和右心房压力下降，同时左心室舒张功能恢复；血流动力学和临床改善与脑钠肽减少和游离 T3 水平升高有关。他们所有人的游离 T3 水平都增加了，其中 6 名（42%）患者的水平恢复正常。游离 T4 和 TSH 值保持不变。
这些数据表明，急性失代偿性 HF 患者中的 LT3S 可用于评估疾病的状态和临床过程。这些初步结果表明，LT3S 的可逆性与持续严重心力衰竭患者短期血流动力学和神经激素改善相关。
