Atrial and ventricular flows across a transcatheter mitral valve

• Published in: Interactive cardiovascular and thoracic surgery 2021-06, Vol.33 (1), p.1-9
• Main Authors: Hatoum, Hoda, Askegaard, Gunnar, Iyer, Ramji, Prasad Dasi, Lakshmi
• Format: Article
• Language: English
• Subjects: Adult Cardiac; Cardiac Catheterization; Heart Valve Diseases - surgery; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve - diagnostic imaging; Mitral Valve - surgery; Mitral Valve Insufficiency - diagnostic imaging; Mitral Valve Insufficiency - surgery; Treatment Outcome
• ISSN: 1569-9285; 1569-9293; 1569-9285
• DOI: 10.1093/icvts/ivab032

Abstract   OBJECTIVES The objective of this study was to evaluate the haemodynamic performance of transcatheter mitral valve replacement (TMVR) Implant with a focus on turbulence and washout adjacent to the ventricular surface of the leaflets. TMVR holds the promise of treating a large spectrum of mitral valve diseases. However, the haemodynamic performance and flow dynamics of such replacements are not fully understood. METHODS A tri-leaflet biopsrosthetic TMVR represented by Caisson implant of size 36A was implanted in the mitral position of a left heart simulator pulse duplicating system under physiological conditions. The 36A implant covers an anterior–posterior range of 26–32 mm and a commissure-to-commissure range of 30–36 mm. Transmitral pressure gradient, effective orifice area and regurgitant fraction were calculated. Particle image velocimetry was performed to evaluate turbulence in 2 perpendicular planes (Reynolds and viscous shear stresses, respectively). Additionally, dye experiments were performed to visualize washout. RESULTS Transmitral pressure gradient was 1.29 ± 0.27 mmHg and effective orifice area was 2.96 ± 0.28 cm2. Regurgitant fraction was 14.13 ± 0.08%. Total washout was 4.27 cardiac cycles. Largest viscous shear stress reaches 3.7 Pa and 2.4 Pa in ventricle and atrium, respectively. Reynolds shear stress in the atrial side was