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Author Notes:

Ajit P. Yoganathan, PhD, 313 Ferst Drive, Atlanta, GA 30332 (ajit.yoganathan@bme.gatech.edu)

We acknowledge the contributions to and development of the data acquisition platform provided by members of the Cardiovascular Research Unit in Århus, Denmark.

Authors have nothing to disclose with regard to commercial support.

Subjects:

Research Funding:

This study was supported by a research grant awarded from the Food and Drug Administration (FDA1061718); and by grants from the National Heart, Lung and Blood Institute of the National Institutes of Health, Bethesda, Md. (HL63954 and HL73021).

Dr Gorman and Dr Gorman were supported by individual Established Investigator Awards from the American Heart Association, Dallas, Tex.

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Cardiac & Cardiovascular Systems
  • Respiratory System
  • Surgery
  • Cardiovascular System & Cardiology
  • IN-VIVO
  • ANNULOPLASTY

Contractile mitral annular forces are reduced with ischemic mitral regurgitation

Tools:

Journal Title:

Journal of Thoracic and Cardiovascular Surgery

Volume:

Volume 146, Number 2

Publisher:

, Pages 422-428

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Objective: Forces acting on mitral annular devices in the setting of ischemic mitral regurgitation are currently unknown. The aim of this study was to quantify the cyclic forces that result from mitral annular contraction in a chronic ischemic mitral regurgitation ovine model and compare them with forces measured previously in healthy animals. Methods: A novel force transducer was implanted in the mitral annulus of 6 ovine subjects 8 weeks after an inferior left ventricle infarction that produced progressive, severe chronic ischemic mitral regurgitation. Septal-lateral and transverse forces were measured continuously for cardiac cycles reaching a peak left ventricular pressure of 90, 125, 150, 175, and 200 mm Hg. Cyclic forces and their rate of change during isovolumetric contraction were quantified and compared with those measured in healthy animals. Results: Animals with chronic ischemic mitral regurgitation exhibited a mean mitral regurgitation grade of 2.3 ± 0.5. Ischemic mitral regurgitation was observed to decrease significantly septal-lateral forces at each level of left ventricular pressure (P <.01). Transverse forces were consistently lower in the ischemic mitral regurgitation group despite not reaching statistical significance. The rate of change of these forces during isovolumetric contraction was found to increase significantly with peak left ventricular pressure (P <.005), but did not differ significantly between animal groups. Conclusions: Mitral annular forces were measured for the first time in a chronic ischemic mitral regurgitation animal model. Our findings demonstrated an inferior left ventricular infarct to decrease significantly cyclic septal-lateral forces while modestly lowering those in the transverse. The measurement of these forces and their variation with left ventricular pressure contributes significantly to the development of mitral annular ischemic mitral regurgitation devices.

Copyright information:

© 2013 by The American Association for Thoracic Surgery.

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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