Quantification and Analysis of Leaflet Flutter on Biological Prosthetic Cardiac Valves

Abstract

The use of porcine or bovine pericardium biological cardiac valves has as its main disadvantage a relatively short lifespan, with failures due to calcification and fatigue. Increasing these valves' durability constitutes a great challenge. An understudied phenomenon is the effect of flutter, an oscillation of the leaflets that can cause regurgitation and accelerate calcification and fatigue. As a starting point to study how to reduce or prevent these oscillations, a method was developed to quantify the flutter frequencies occurring at the point of the valve's full opening. On a test bench that simulates the heart flow, the cusp behaviors of eight biological valves were filmed with a high speed camera at 2000 frames per second at different flow rates and motion capture software obtained the frequencies and amplitudes of the vibrations of each leaflet. Oscillations in the range of 200 Hz with average amplitudes of 0.4 mm were found; larger nominal diameter valves obtained lower values, and bovine pericardial valves had superior performance compared to porcine valves. A dimensionless analysis was performed to find a relationship between the geometric and mechanical properties of the valves with the critical speed of the onset of fluttering. This relationship inspired a method to predict whether flutter will occur in the bioprosthesis. This method is a new tool for the consideration of maximizing the life of prosthetic valves.

Bio-inspired anisotropic polymeric heart valves exhibiting valve-like mechanical and hemodynamic behavior

“…Difference in morphology change during systole may be attributed to isotropy and anisotropy of these PHVs. Compared with the isotropic PEGDA-ISF leaflet, the anisotropic PEGDA-ASF leaflet was more flexible in the radial direction, resulting in appropriate morphology change during systole similar to biological heart valve (e.g., bovine pericardial valve, porcine heart valve) as previously reported [53,54,58,59]. The hydrodynamic curves of the PHVs from PEGDA-ASF composites (Fig.…”

Design, Analysis and Testing of a Novel Mitral Valve for Transcatheter Implantation

“…This solution was preferred to minimise the risk of ventricular outflow tract obstruction, by decreasing the tendency of the leaflets to diverge from their design configuration, especially when the valve is placed in annuli significantly smaller than the nominal valve dimension. Also, shorter free edges were observed to reduce the leaflets fluttering during diastole, which is typically associated with increased calcification, haemolysis, regurgitation and early fatigue failure 6. A scale factor ( SF ), defined as the ratio between the outlet ( D V ) and inlet ( D A ) intertrigonal dimensions of the device (Fig.…”

Quantification of leaflet flutter in bioprosthetic heart valves using fluid-structure interaction analysis

“…Experimental works have been completed to establish methods for quantifying the flutter of BHV leaflets. These approaches utilize different methods for tracking the leaflet free edge motion with varying levels of accuracy [15,16].…”

“…[15], a video-based approach is generally implemented to capture valve motion by tracking theleaflet free edges frame by frame. This ultimately enables experimental flutter quantification.…”

“…The Pearson correlation coefficient (r) and the Spearman correlation coefficient (rho) were determined for linear correlation analysis. Bland and Altman plots[15] were calculated to establish the degree of concordance and agreement between the morphological parameters.…”