Mizuguchi Yukio, Oishi Yoshifumi, Miyoshi Hirokazu, Iuchi Arata, Nagase Norio, Ara Nusrat, Oki Takashi
Cardiovascular Section, Higashi Tokushima National Hospital, National Hospital Organization, 1-1 Ohmukai-kita, Ohtera, Itano, Itano, Tokushima 779-0193, Japan.
Eur J Echocardiogr. 2010 Sep;11(8):690-7. doi: 10.1093/ejechocard/jeq044. Epub 2010 Apr 10.
Left ventricular (LV) torsion may be an important component of normal LV systolic function. However, its mechanics remain unresolved. Two-dimensional (2-D) strain imaging is increasingly used to quantify LV torsion in the clinical setting. Telmisartan has cardioreparative effects, including attenuation of subendocardial myocardial fibrosis and improvement of LV remodelling. To clarify the mechanisms of LV torsion, in the present study, we evaluated changes in LV longitudinal deformation and torsion after medication with telmisartan using 2-D strain imaging in patients with hypertension (HT).
Telmisartan (20-40 mg daily) was administered to 37 previously untreated patients with HT. Two-dimensional strain echocardiography was performed after medication had been continued for 1-2 months with normal values for blood pressure (BP) (phase I) and for 12 months (phase II). In the phase II, relative LV wall thickness, LV mass index, LV torsion, and torsional rate were reduced, whereas the mean peak systolic longitudinal strain and strain rate were increased, compared to the phase I. LV torsion correlated well with relative LV wall thickness, but not LV mass index.
Our results obtained from cardioreparative effects of telmisartan suggested that LV torsion is associated with systolic longitudinal deformation related to subendocardial myocardial fibrosis, and/or LV concentric hypertrophy-related difference in torques between the subendocardial and subepicardial sides.
左心室(LV)扭转可能是正常左心室收缩功能的重要组成部分。然而,其力学机制仍未明确。二维(2-D)应变成像在临床环境中越来越多地用于量化左心室扭转。替米沙坦具有心脏修复作用,包括减轻心内膜下心肌纤维化和改善左心室重构。为了阐明左心室扭转的机制,在本研究中,我们使用二维应变成像评估了高血压(HT)患者服用替米沙坦后的左心室纵向变形和扭转变化。
对37例既往未接受治疗的高血压患者给予替米沙坦(每日20 - 40 mg)。在血压(BP)正常的情况下持续用药1 - 2个月后(I期)以及用药12个月后(II期)进行二维应变超声心动图检查。与I期相比,II期时相对左心室壁厚度、左心室质量指数、左心室扭转和扭转速率降低,而平均收缩期纵向应变峰值和应变率增加。左心室扭转与相对左心室壁厚度密切相关,但与左心室质量指数无关。
我们从替米沙坦的心脏修复作用中获得的结果表明,左心室扭转与心内膜下心肌纤维化相关的收缩期纵向变形和/或心内膜下与心外膜侧之间与左心室同心肥厚相关的扭矩差异有关。