Role of Vortices in Growth of Microbubbles at Mitral Mechanical Heart Valve Closure.
From: Department of Aeronautics and Bioengineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA. edmond.rambod@bioquantetics.com
Annals of biomedical engineering
- Publish Date: Jul 2007
- ISSN: 0090-6964
- Volume: 35
- Issue: 7
- Pages: 1131-45
- Medium: Print
- Language: English
- Citation (JAMA): Rambod Edmond, Beizai Masoud, Sahn David J, et al. Role of Vortices in Growth of Microbubbles at Mitral Mechanical Heart Valve Closure.. Jul 2007;35:1131-45
Abstract
This study is aimed at refining our understanding of the role of vortex formation at mitral mechanical heart valve (MHV) closure and its association with the high intensity transient signals (HITS) seen in echocardiographic studies with MHV recipients. Previously reported numerical results described a twofold process leading to formation of gas-filled microbubbles in-vitro: (1) nucleation and (2) growth of micron size bubbles. The growth itself consists of two processes: (a) diffusion and (b) sudden pressure drop due to valve closure. The role of diffusion has already been shown to govern the initial growth of nuclei. Pressure drop at mitral MHV closure may be attributed to other phenomena such as squeezed flow, water hammer and primarily, vortex cavitation. Mathematical analysis of vortex formation at mitral MHV closure revealed that a closing velocity of approximately 12 m/s can induce a strong regurgitant vortex which in return can instigate a local pressure drop of about 0.9 atm. A 2D experimental model of regurgitant flows was used to substantiate the impact of vortices. At simulated flow and pressure conditions, a regurgitant vortex was observed to drastically enlarge micron size hydrogen bubbles at its core.
Mesh Headings (Keywords): Blood Pressure, Heart Valve Prosthesis, Microbubbles, Models, Cardiovascular, Prosthesis Failure
Check for Full Text / PubMed Unique Identifier (PMID): 17404890
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.