Marcin Malinowski1, Alistair G Proudfoot2, Lenora Eberhart2, Hans Schubert2, Jeremy Wodarek2, David Langholz2, Manuel K Rausch3, Tomasz A Timek4. 1. Meijer Heart and Vascular Institute at Spectrum Health, 100 Michigan Ave NE, Grand Rapids, MI 49503, USA; Department of Cardiac Surgery, Medical University of Silesia, School of Medicine in Katowice, Ziołowa 47, 40635 Katowice, Poland. 2. Meijer Heart and Vascular Institute at Spectrum Health, 100 Michigan Ave NE, Grand Rapids, MI 49503, USA. 3. Department of Aerospace Engineering & Engineering Mechanics, Department of Biomedical Engineering, Institute for Computational Engineering and Science, University of Texas at Austin, 210 E 24th Street, Austin, TX 78703, USA. 4. Meijer Heart and Vascular Institute at Spectrum Health, 100 Michigan Ave NE, Grand Rapids, MI 49503, USA. Electronic address: Tomasz.Timek@spectrumhealth.org.
Abstract
BACKGROUND: Functional tricuspid regurgitation (FTR) commonly arises secondary to conditions affecting the left heart and is associated with right ventricular dysfunction and tricuspid annular dilatation. We set out to establish an animal model of acute RV failure (RVF) with FTR resembling the clinical features. METHODS: Ten adult sheep had pressure sensors placed in the LV, RV, and right atrium while sonomicrometry crystals were implanted around tricuspid annulus and on the RV. Animals were studied open-chest to assess for RV function and FTR after: (1) volume infusion, (2) pulmonary artery constriction, (3) 5 min posterior descending artery occlusion, and (4) combination of all interventions. Hemodynamic, echocardiographic, and sonomicrometry data were collected at baseline and after every intervention. RV dimensions, RV strain, and annular area, perimeter, and size were calculated from crystal coordinates. The model was validated in six additional sheep studied only before and after combined interventions. RESULTS: Neither volume infusion, pulmonary hypertension, nor ischemia were associated with RVF or clinically significant TR when applied separately but combined resulted in RVF and greater than moderate FTR. In the validation group, maximal RV volume increased (62 ± 14 vs 70 ± 16 ml, p = 0.006), contractility decreased (20 ± 6 vs 12 ± 2%, p = 0.02), and strain increased. FTR increased from 0.4 ± 0.5 to 2.5 ± 0.8 (p < 0.001) and annular area from 652 ± 87 mm2 to 739 ± 87 mm2 (p = 0.005). CONCLUSIONS: The developed ovine model of acute RVF was associated with significant annular and RV enlargement and FTR. This novel and clinically pertinent research platform offers insight into the acute RVF pathophysiology and can be utilized to evaluate treatment interventions.
BACKGROUND:Functional tricuspid regurgitation (FTR) commonly arises secondary to conditions affecting the left heart and is associated with right ventricular dysfunction and tricuspid annular dilatation. We set out to establish an animal model of acute RV failure (RVF) with FTR resembling the clinical features. METHODS: Ten adult sheep had pressure sensors placed in the LV, RV, and right atrium while sonomicrometry crystals were implanted around tricuspid annulus and on the RV. Animals were studied open-chest to assess for RV function and FTR after: (1) volume infusion, (2) pulmonary artery constriction, (3) 5 min posterior descending artery occlusion, and (4) combination of all interventions. Hemodynamic, echocardiographic, and sonomicrometry data were collected at baseline and after every intervention. RV dimensions, RV strain, and annular area, perimeter, and size were calculated from crystal coordinates. The model was validated in six additional sheep studied only before and after combined interventions. RESULTS: Neither volume infusion, pulmonary hypertension, nor ischemia were associated with RVF or clinically significant TR when applied separately but combined resulted in RVF and greater than moderate FTR. In the validation group, maximal RV volume increased (62 ± 14 vs 70 ± 16 ml, p = 0.006), contractility decreased (20 ± 6 vs 12 ± 2%, p = 0.02), and strain increased. FTR increased from 0.4 ± 0.5 to 2.5 ± 0.8 (p < 0.001) and annular area from 652 ± 87 mm2 to 739 ± 87 mm2 (p = 0.005). CONCLUSIONS: The developed ovine model of acute RVF was associated with significant annular and RV enlargement and FTR. This novel and clinically pertinent research platform offers insight into the acute RVF pathophysiology and can be utilized to evaluate treatment interventions.
Authors: William D Meador; Mrudang Mathur; Gabriella P Sugerman; Tomasz Jazwiec; Marcin Malinowski; Matthew R Bersi; Tomasz A Timek; Manuel K Rausch Journal: Acta Biomater Date: 2019-11-22 Impact factor: 8.947
Authors: Michael Nguyen-Truong; Wenqiang Liu; June Boon; Brad Nelson; Jeremiah Easley; Eric Monnet; Zhijie Wang Journal: Animal Model Exp Med Date: 2020-06-14
Authors: Chung-Hao Lee; Devin W Laurence; Colton J Ross; Katherine E Kramer; Anju R Babu; Emily L Johnson; Ming-Chen Hsu; Ankush Aggarwal; Arshid Mir; Harold M Burkhart; Rheal A Towner; Ryan Baumwart; Yi Wu Journal: Bioengineering (Basel) Date: 2019-05-22