大鼠急性梗死期间冠状动脉驱动压力降低导致远隔心肌的心内膜下纤维化。

Subendocardial fibrosis in remote myocardium results from reduction of coronary driving pressure during acute infarction in rats.

作者信息

de Carvalho Frimm Clovis, Koike Marcia Kiyomi, Cúri Mariana

机构信息

Medical School, University of São Paulo, São Paulo, Brazil.

出版信息

Arq Bras Cardiol. 2003 May;80(5):509-20. Epub 2003 May 30.

PMID:12792716

Abstract

OBJECTIVE

To investigate the role of hemodynamic changes occurring during acute MI in subsequent fibrosis deposition within non-MI.

METHODS

By using the rat model of MI, 3 groups of 7 rats each [sham, SMI (MI <30%), and LMI (MI >30%)] were compared. Systemic and left ventricular (LV) hemodynamics were recorded 10 minutes before and after coronary artery ligature. Collagen volume fraction (CVF) was calculated in picrosirius red-stained heart tissue sections 4 weeks later.

RESULTS

Before surgery, all hemodynamic variables were comparable among groups. After surgery, LV end-diastolic pressure increased and coronary driving pressure decreased significantly in the LMI compared with the sham group. LV dP/dt max and dP/dt min of both the SMI and LMI groups were statistically different from those of the sham group. CVF within non-MI interventricular septum and right ventricle did not differ between each MI group and the sham group. Otherwise, subendocardial (SE) CVF was statistically greater in the LMI group. SE CVF correlated negatively with post-MI systemic blood pressure and coronary driving pressure, and positively with post-MI LV dP/dt min. Stepwise regression analysis identified post-MI coronary driving pressure as an independent predictor of SE CVF.

CONCLUSION

LV remodeling in rats with MI is characterized by predominant SE collagen deposition in non-MI and results from a reduction in myocardial perfusion pressure occurring early on in the setting of MI.

摘要

目的

研究急性心肌梗死期间发生的血流动力学变化在随后非梗死心肌纤维化沉积中的作用。

方法

使用大鼠心肌梗死模型，比较3组，每组7只大鼠[假手术组、轻度心肌梗死组（梗死面积<30%）和重度心肌梗死组（梗死面积>30%）]。在冠状动脉结扎前后10分钟记录全身和左心室血流动力学。4周后在天狼星红染色的心脏组织切片中计算胶原容积分数（CVF）。

结果

手术前，各组间所有血流动力学变量均具有可比性。手术后，与假手术组相比，重度心肌梗死组左心室舒张末期压力升高，冠状动脉驱动压力显著降低。轻度心肌梗死组和重度心肌梗死组的左心室dp/dt max和dp/dt min与假手术组相比均有统计学差异。各心肌梗死组与假手术组之间非梗死室间隔和右心室的CVF无差异。否则，重度心肌梗死组的心内膜下（SE）CVF在统计学上更高。SE CVF与心肌梗死后的全身血压和冠状动脉驱动压力呈负相关，与心肌梗死后的左心室dp/dt min呈正相关。逐步回归分析确定心肌梗死后冠状动脉驱动压力是SE CVF的独立预测因子。