A fibrose subendocárdica que acompanha o remodelamento ventricular do infarto do miocárdio está associada a redução da pressão de perfusão coronariana durante a fase aguda / Subendocardial fibrosis in remote myocardium results from reduction of coronary driving pressure during acute infarction in rats
Arq. bras. cardiol
; 80(5): 509-520, May 2003. ilus, tab, graf
Article
in English, Portuguese
| LILACS
| ID: lil-336448
Responsible library:
BR1.1
RESUMO
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 percent), and LMI (MI >30 percent)] 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
Full text:
Available
Collection:
International databases
Database:
LILACS
Main subject:
Blood Pressure
/
Fibrosis
/
Ventricular Remodeling
/
Endocardium
/
Heart Ventricles
/
Myocardial Infarction
Type of study:
Prognostic study
Limits:
Animals
Language:
English
/
Portuguese
Journal:
Arq. bras. cardiol
Journal subject:
Cardiology
Year:
2003
Document type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade de São Paulo/BR