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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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Related in: MedlinePlus

Coronary angiography to detect vessel closure in operated pigs induced by ameroid constrictor.The pericardium was opened and a 2.5-mm ameroid constrictor (A, B) was implanted around the left circumflex coronary artery (C). Representative images show x-ray angiographs from the left coronary system in pig hearts at one (D), two (E), and four (F) weeks, post-surgery. Arrow depicts the ameroid constrictor.
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pone-0111689-g001: Coronary angiography to detect vessel closure in operated pigs induced by ameroid constrictor.The pericardium was opened and a 2.5-mm ameroid constrictor (A, B) was implanted around the left circumflex coronary artery (C). Representative images show x-ray angiographs from the left coronary system in pig hearts at one (D), two (E), and four (F) weeks, post-surgery. Arrow depicts the ameroid constrictor.

Mentions: The ameroid constrictor was used to cause vessel closure, which resulted in 10–20% closure at one week, 30–40% closure at two weeks and 90–100% closure at four weeks post-implantation in pigs as well as using the angiographic guide wire as a scale (diameter: 0.21 cm) (Figure 1). ECG parameters were stable in pig hearts for up to four weeks after the surgery. As compared to the baseline, the terminal force of the p wave in lead V1 (PTFv1) was significantly reduced from 0.042±0.031 mm·s to 0.021±0.017 mm·s at four weeks post-surgery in pig hearts. Analysis of leads I, aVL, V5 and V6 displayed signs of ST segment elevation and T-wave inversion. Pathological Q waves were also observed in leads V1 and V2. These leads also revealed ST-segment depression indicative of left ventricular and atrial wall ischemia. The decreased P terminal force v1 (PTFv1) implied increased left atrial diameter and left ventricular diastolic volume load.


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)

Coronary angiography to detect vessel closure in operated pigs induced by ameroid constrictor.The pericardium was opened and a 2.5-mm ameroid constrictor (A, B) was implanted around the left circumflex coronary artery (C). Representative images show x-ray angiographs from the left coronary system in pig hearts at one (D), two (E), and four (F) weeks, post-surgery. Arrow depicts the ameroid constrictor.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0111689-g001: Coronary angiography to detect vessel closure in operated pigs induced by ameroid constrictor.The pericardium was opened and a 2.5-mm ameroid constrictor (A, B) was implanted around the left circumflex coronary artery (C). Representative images show x-ray angiographs from the left coronary system in pig hearts at one (D), two (E), and four (F) weeks, post-surgery. Arrow depicts the ameroid constrictor.
Mentions: The ameroid constrictor was used to cause vessel closure, which resulted in 10–20% closure at one week, 30–40% closure at two weeks and 90–100% closure at four weeks post-implantation in pigs as well as using the angiographic guide wire as a scale (diameter: 0.21 cm) (Figure 1). ECG parameters were stable in pig hearts for up to four weeks after the surgery. As compared to the baseline, the terminal force of the p wave in lead V1 (PTFv1) was significantly reduced from 0.042±0.031 mm·s to 0.021±0.017 mm·s at four weeks post-surgery in pig hearts. Analysis of leads I, aVL, V5 and V6 displayed signs of ST segment elevation and T-wave inversion. Pathological Q waves were also observed in leads V1 and V2. These leads also revealed ST-segment depression indicative of left ventricular and atrial wall ischemia. The decreased P terminal force v1 (PTFv1) implied increased left atrial diameter and left ventricular diastolic volume load.

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