Department of Medicine, University of Otago, Dunedin, New Zealand.
Department of Pharmacology, University of Otago, Dunedin, New Zealand.
PLoS One. 2019 Aug 12;14(8):e0220837. doi: 10.1371/journal.pone.0220837. eCollection 2019.
Is global longitudinal strain (GLS) a more accurate non-invasive measure of histological myocardial fibrosis than left ventricular ejection fraction (LVEF) in a hypertensive rodent model.
Hypertension results in left ventricular hypertrophy and cardiac dysfunction. Speckle-tracking echocardiography has emerged as a robust technique to evaluate cardiac function in humans compared with standard echocardiography. However, its use in animal studies is less clearly defined.
Cyp1a1Ren2 transgenic rats were randomly assigned to three groups; normotensive, untreated hypertensive or hypertensive with daily administration of spironolactone (human equivalent dose of 50 mg/day). Cardiac function and interstitial fibrosis development were monitored for three months.
The lower limit of normal LVEF was calculated to be 75%. After three months hypertensive animals (196±21 mmHg systolic blood pressure (SBP)) showed increased cardiac fibrosis (8.8±3.2% compared with 2.4±0.7% % in normals), reduced LVEF (from 81±2% to 67±7%) and impaired myocardial GLS (from -17±2% to -11±2) (all p<0.001). Myocardial GLS demonstrated a stronger correlation with cardiac interstitial fibrosis (r2 = 0.58, p<0.0001) than LVEF (r2 = 0.37, p<0.006). Spironolactone significantly blunted SBP elevation (184±15, p<0.01), slowed the progression of cardiac fibrosis (4.9±1.4%, p<0.001), reduced the decline in LVEF (72±4%, p<0.05) and the degree of impaired myocardial GLS (-13±1%, p<0.01) compared to hypertensive animals.
This study has demonstrated that, myocardial GLS is a more accurate non-invasive measure of histological myocardial fibrosis compared to standard echocardiography, in an animal model of both treated and untreated hypertension. Spironolactone blunted the progression of cardiac fibrosis and deterioration of myocardial GLS.
在高血压啮齿动物模型中，与左心室射血分数（LVEF）相比，整体纵向应变（GLS）是否是组织学心肌纤维化的更准确的无创测量指标。
高血压会导致左心室肥大和心功能障碍。斑点追踪超声心动图已成为一种强大的技术，可与标准超声心动图相比评估人类的心脏功能。但是，其在动物研究中的应用尚不清楚。
将 Cyp1a1Ren2 转基因大鼠随机分为三组；正常血压、未治疗的高血压或每日给予螺内酯（相当于人类 50mg/天的剂量）的高血压。监测三个月的心脏功能和间质纤维化的发展。
正常 LVEF 的下限计算为 75％。三个月后，高血压动物（收缩压 196±21mmHg）显示出心肌纤维化增加（与正常组相比为 2.4±0.7％，增加了 8.8±3.2％），LVEF 降低（从 81±2％降至 67±7％）和心肌 GLS 受损（从-17±2％降至-11±2％）（均p<0.001）。心肌 GLS 与心肌间质纤维化的相关性（r2=0.58，p<0.0001）强于 LVEF（r2=0.37，p<0.006）。螺内酯显著降低收缩压升高（184±15，p<0.01），减缓心脏纤维化的进展（4.9±1.4％，p<0.001），降低 LVEF 的下降（72±4％，p<0.05）和受损的心肌 GLS 程度（-13±1％，p<0.01）与高血压动物相比。
这项研究表明，与标准超声心动图相比，在高血压的治疗和未治疗的动物模型中，心肌 GLS 是组织学心肌纤维化的更准确的无创测量指标。螺内酯可减轻心脏纤维化和心肌 GLS 恶化的进展。
