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A pig model of ischemic mitral regurgitation induced by mitral chordae tendinae rupture and implantation of an ameroid constrictor.

Cui YC, Li K, Tian Y, Yuan WM, Peng P, Yang JZ, Zhang BJ, Zhang HD, Wu AL, Tang Y - PLoS ONE (2014)

Bottom Line: Blood velocity of the mitral regurgitation was found to be between medium and high levels.LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline.The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing Municipal Key Laboratory for Pre-clinical Evaluation of Cardiovascular Implantation Devices, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China.

ABSTRACT
A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10-20% at one week, 30-40% at two weeks and 90-100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.

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MRI analysis of operated pig hearts.A: Representative long-axis view of the left ventricle; B: Blood flow analysis in the same MRI plane; C: Representative short-axis view of the mitral valve. Arrow depicts regurgitation aperture of the mitral valve. Circle depicts regurgitation of blood.
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pone-0111689-g005: MRI analysis of operated pig hearts.A: Representative long-axis view of the left ventricle; B: Blood flow analysis in the same MRI plane; C: Representative short-axis view of the mitral valve. Arrow depicts regurgitation aperture of the mitral valve. Circle depicts regurgitation of blood.

Mentions: Cardiac MRI was performed in pig hearts at baseline and eight weeks post-surgery (Figure 5). MRI results indicated a shift in the mitral valve orifice. Systolic regurgitation displayed an eccentric shape while entering the left atrium, which then spread immediately to the left atrium and left atrial posterior wall (Figure 5A and 5B). Regurgitation characteristics observed via MRI were consistent with those observed using color Doppler imaging. The short axis view of the mitral valve indicated that the mitral muscle was dysfunctional (Figure 5C).


A pig model of ischemic mitral regurgitation induced by mitral chordae tendinae rupture and implantation of an ameroid constrictor.

Cui YC, Li K, Tian Y, Yuan WM, Peng P, Yang JZ, Zhang BJ, Zhang HD, Wu AL, Tang Y - PLoS ONE (2014)

MRI analysis of operated pig hearts.A: Representative long-axis view of the left ventricle; B: Blood flow analysis in the same MRI plane; C: Representative short-axis view of the mitral valve. Arrow depicts regurgitation aperture of the mitral valve. Circle depicts regurgitation of blood.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257529&req=5

pone-0111689-g005: MRI analysis of operated pig hearts.A: Representative long-axis view of the left ventricle; B: Blood flow analysis in the same MRI plane; C: Representative short-axis view of the mitral valve. Arrow depicts regurgitation aperture of the mitral valve. Circle depicts regurgitation of blood.
Mentions: Cardiac MRI was performed in pig hearts at baseline and eight weeks post-surgery (Figure 5). MRI results indicated a shift in the mitral valve orifice. Systolic regurgitation displayed an eccentric shape while entering the left atrium, which then spread immediately to the left atrium and left atrial posterior wall (Figure 5A and 5B). Regurgitation characteristics observed via MRI were consistent with those observed using color Doppler imaging. The short axis view of the mitral valve indicated that the mitral muscle was dysfunctional (Figure 5C).

Bottom Line: Blood velocity of the mitral regurgitation was found to be between medium and high levels.LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline.The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing Municipal Key Laboratory for Pre-clinical Evaluation of Cardiovascular Implantation Devices, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China.

ABSTRACT
A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10-20% at one week, 30-40% at two weeks and 90-100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.

Show MeSH
Related in: MedlinePlus