Left Ventricular Thinning and Distension in Pig Hearts as a Reproducible Ex Vivo Model of Functional Mitral Regurgitation
| Autor: | Kirthana Sreerangathama Suresh, Qi He, Robert A. Guyton, Muralidhar Padala, Daisuke Onohara, Elorm J Agra |
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| Rok vydání: | 2020 |
| Předmět: |
Cardiac output
medicine.medical_specialty Swine Heart Ventricles Biomedical Engineering Biophysics Pulsatile flow Hemodynamics Bioengineering 030204 cardiovascular system & hematology Distension Article Biomaterials 03 medical and health sciences 0302 clinical medicine Internal medicine Mitral valve Animals Medicine cardiovascular diseases Enlarged heart Mitral regurgitation business.industry Mitral Valve Insufficiency General Medicine medicine.disease Disease Models Animal medicine.anatomical_structure 030228 respiratory system cardiovascular system Cardiology Ventricular pressure business Dilatation Pathologic |
| Zdroj: | ASAIO J |
| ISSN: | 1058-2916 |
| DOI: | 10.1097/mat.0000000000001145 |
| Popis: | OBJECTIVE: Functional mitral regurgitation in the setting of an enlarged heart is challenging to repair surgically with an annular approach, and the need to develop sub-annular and ventricular approaches is recognized yet unrealized due to the lack of models for investigations. In this study, we report a novel model of functional mitral regurgitation induced by left ventricular thinning and distension in pig hearts. METHODS: Seven pig hearts were explanted at a local slaughterhouse, and left ventricular distension induced by thinning the ventricular myocardium by 60–65% of its original thickness. Distension of the thinned hearts with a 120mmHg column, confirmed significant left ventricular dilatation and mitral valve tethering. These hearts were then mounted into a pulsatile flow model, and animated at 120mm Hg left ventricular pressure, 5L/min cardiac output at 70 beats per minute. Echocardiography was used to assess valvular kinematics and hemodynamics. RESULTS: Left ventricular wall thickness reduced by 60.5±10.1% at the basal plane, 64.8±11.3% at the equatorial plane and 64.0±11.4% at the apical plane after thinning. Upon distension, ventricular volumes increased by 852.4±639.8% after LV thinning, with an 89.5±33.9% increase in sphericity index. Mitral valve systolic tenting height increased from 7.92±2.06 mm to 15.02±3.89 mm, systolic tethering area increased from 130.7±38.2 mm(2) to 409.9±124.6 mm(2) and an average mitral regurgitation fraction of 24.4±16.6% was measured. In a case study, use of multi-modality imaging to test the efficacy of transcatheter mitral devices was confirmed. CONCLUSIONS: Ventricular wall thinning leading to passive left ventricular distension and dilatation is a reproducible ex vivo model of mitral valve tethering and functional mitral regurgitation, which in combination with multi-modality imaging provides a good simulation model. |
| Databáze: | OpenAIRE |
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