Akcakoyun Mustafa, Kaya Hasan, Kargin Ramazan, Pala Selcuk, Emiroglu Yunus, Esen Ozlem, Karapinar Hekim, Kaya Zekeriya, Esen Ali Metin
Specialist Cevizli mahallesi, Keban sokak, Oba Apartmani, No: 5, Daire: 9 Kartal, Istanbul, Turkey.
J Clin Endocrinol Metab. 2009 Aug;94(8):2979-83. doi: 10.1210/jc.2009-0117. Epub 2009 May 19.
Response of systolic and diastolic velocities of mitral annulus to exercise in patients with subclinical hypothyroidism (SCH) has not been explored previously. We sought to investigate whether SCH is associated with abnormal left ventricular (LV) longitudinal function reserve to exercise.
Mitral annular systolic (S') and early diastolic (E') velocities were measured at rest and during supine bicycle exercise using tissue Doppler echocardiography (TDE) in 23 patients with newly diagnosed SCH and 25 controls. LV diastolic and systolic longitudinal function reserve indices were calculated.
There were no significant differences in mitral inflow velocities at rest between groups except for LV end-diastolic dimension and LV end-systolic dimension, which were higher in the control group. E' and S' at rest were also similar between the groups. However, S' (9.8 +/- 1.5 vs. 11.3 +/- 1.5 cm/sec at 25 W, P = 0.001; and 11.3 +/- 1.8 vs. 13.1 +/- 1.8 cm/sec at 50 W, P = 0.001) and E' (13.8 +/- 1.4 vs. 15.7 +/- 1.6 cm/sec at 25 W, P < 0.001; and 15.6 +/- 1.6 vs. 18.2 +/- 1.5 cm/sec at 50 W, P < 0.001) during exercise were significantly lower in patients with SCH. Longitudinal systolic and diastolic function reserve indices were significantly lower in patients with SCH (systolic index, 1.4 +/- 0.9 vs. 2.5 +/- 0.9 cm/sec at 25 W, P = 0.001; and 2.7 +/- 1.3 vs. 4.1 +/- 1.2 cm/sec at 50 W, P = 0.001; diastolic index, 2.3 +/- 1.3 vs. 3.6 +/- 1.5 cm/sec at 25 W, P = 0.003; and 3.9 +/- 1.6 vs. 5.9 +/- 1.3 cm/sec at 50 W, P < 0.001).
Assessment of LV longitudinal functional reserve with exercise using TDE appears to be helpful in identifying early myocardial dysfunction in SCH.
亚临床甲状腺功能减退症（SCH）患者二尖瓣环收缩期和舒张期速度对运动的反应此前尚未被探究。我们试图研究SCH是否与运动时左心室（LV）纵向功能储备异常相关。
使用组织多普勒超声心动图（TDE）对23例新诊断的SCH患者和25例对照者在静息状态和仰卧位自行车运动期间测量二尖瓣环收缩期（S'）和舒张早期（E'）速度。计算左心室舒张期和收缩期纵向功能储备指数。
除左心室舒张末期内径和左心室收缩末期内径外，两组静息时二尖瓣血流速度无显著差异，对照组的这两项指标更高。两组静息时的E'和S'也相似。然而，SCH患者运动期间的S'（25W时为9.8±1.5 vs. 11.3±1.5cm/秒，P = 0.001；50W时为11.3±1.8 vs. 13.1±1.8cm/秒，P = 0.001）和E'（25W时为13.8±1.4 vs. 15.7±1.6cm/秒，P < 0.001；50W时为15.6±1.6 vs. 18.2±1.5cm/秒，P < 0.001）显著更低。SCH患者的纵向收缩期和舒张期功能储备指数显著更低（收缩期指数，25W时为1.4±0.9 vs. 2.5±0.9cm/秒，P = 0.001；50W时为2.7±1.3 vs. 4.1±1.2cm/秒，P = 0.001；舒张期指数，25W时为2.3±1.3 vs. 3.6±1.5cm/秒，P = 0.003；50W时为3.9±1.6 vs. 5.9±1.3cm/秒，P < 0.001）。
使用TDE评估运动时左心室纵向功能储备似乎有助于识别SCH患者早期心肌功能障碍。
