Comparison of epicardial deformation in passive and active isolated rabbit hearts

Andrew Ho*, Liang Tang, Fu Pen Chiang, Shien-Fong Lin

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Mechanical deformation of isolated rabbit hearts through passive inflation techniques have been a viable form of replicating heart motion, but its relation to the heart's natural active contractions remain unclear. The mechanical properties of the myocardium may show diverse characteristics while in tension and compression. In this study, epicardial strain was measured with the assistance of computer-aided speckle interferometry (CASI)1. CASI tracks the movement of clusters of particles for measuring epicardial deformation. The heart was cannulated and perfused with Tyrode's solution. Silicon carbide particles were applied onto the myocardium to form random speckle pattern images while the heart was allowed to actively contract and stabilize. High resolution videos (1000×1000 pixels) of the left ventricle were taken with a complementary metal oxide semiconductor (CMOS) camera as the heart was actively contracting through electrical pacing at various cycle lengths between 250-800 ms. A latex balloon was then inserted into the left ventricle via left atrium and videos were taken as the balloon was repeatedly inflated and deflated at controlled volumes (1-3 ml/cycle). The videos were broken down into frames and analyzed through CASI. Active contractions resulted in non-uniform circular epicardial and uniaxial contractions at different stages of the motion. In contrast, the passive heart demonstrated very uniform expansion and contraction originating from the source of the latex balloon. The motion of the active heart caused variations in deformation, but in comparison to the passive heart, had a more enigmatic displacement field. The active heart demonstrated areas of large displacement and others with relatively no displacement. Application of CASI was able to successfully distinguish the motions between the active and passive hearts.

Original languageEnglish
Title of host publicationPhotonic Therapeutics and Diagnostics III
DOIs
StatePublished - 31 Aug 2007
EventPhotonic Therapeutics and Diagnostics III - San Jose, CA, United States
Duration: 20 Jan 200721 Jan 2007

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6424
ISSN (Print)1605-7422

Conference

ConferencePhotonic Therapeutics and Diagnostics III
CountryUnited States
CitySan Jose, CA
Period20/01/0721/01/07

Keywords

  • Active
  • CASI
  • Deformation
  • Epicardial
  • Passive
  • Speckle interferometry

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