Faculty of Medicine, Department of Cardiology, Abant Izzet Baysal University, Turkey.
Endokrynol Pol. 2012;63(4):286-93.
Changes of thyroid hormones levels may lead to effects, not only in ventricular function, but also atrial function. The aim of this study was to investigate left atrial (LA) mechanical functions, atrial electromechanical coupling and P wave dispersion in patients with subclinical thyroid disorders.
Eighty patients with subclinical thyroid disorders and forty controls were included. A diagnosis of subclinical thyroid disorders were reached with increased or decreased serum TSH and normal free T4 (fT4) levels. LA volumes were measured using the biplane area length method and LA active and passive emptying volumes and fraction were calculated. Intra- and interatrial electromechanical delay were measured by tissue Doppler imaging (TDI).
All groups had similar demographic findings. LA mechanical functions significantly impaired in subclinical thyroid disorders than control group. Intra- and Interatrial delay, were measured significantly higher in patients with subclinical thyroid disorders than control group. PA lateral and interatrial delay were positively correlated with TSH (r = 0.507, p = 0.006 and r = 0.455, p = 0.015, respectively) in subclinical hypothyroid patients. There was negative correlation between TSH and interatrial delay (r = -0.492, p = 0.006) in subclinical hyperthyroid patients. Linear multivariate regression analysis demonstrated that, TSH was the only an independent factor of interatrial delay in patients with subclinical thyroid disorders.
This study showed that impaired LA mechanical and electromechanical function in subclinical thyroid disorders. TSH was an independent determinant of interatrial delay. Prolonged atrial electromechanical coupling time and impaired mechanical atrial functions may be related to the increased incidence of arrhythmias.
甲状腺激素水平的变化可能会导致心室功能和心房功能的改变。本研究旨在探讨亚临床甲状腺疾病患者左心房（LA）机械功能、心房机电耦联和 P 波离散度。
共纳入 80 例亚临床甲状腺疾病患者和 40 例对照组。亚临床甲状腺疾病的诊断依据为血清 TSH 升高或降低，游离 T4（fT4）水平正常。采用双平面面积长度法测量左心房容积，计算左心房主动排空容积和被动排空容积及分数。采用组织多普勒成像（TDI）测量房间隔内和房间隔间电机械延迟。
所有组的人口统计学特征相似。与对照组相比，亚临床甲状腺疾病患者的 LA 机械功能明显受损。亚临床甲状腺疾病患者的房间隔内和房间隔间延迟明显高于对照组。亚临床甲状腺功能减退患者的 PA 侧壁和房间隔间延迟与 TSH 呈正相关（r = 0.507，p = 0.006 和 r = 0.455，p = 0.015）。亚临床甲状腺功能亢进患者的 TSH 与房间隔间延迟呈负相关（r = -0.492，p = 0.006）。多元线性回归分析显示，TSH 是亚临床甲状腺疾病患者房间隔间延迟的唯一独立因素。
本研究表明，亚临床甲状腺疾病患者的 LA 机械和机电功能受损。TSH 是房间隔间延迟的独立决定因素。延长的房性电机械耦联时间和受损的心房机械功能可能与心律失常发生率的增加有关。
