Myocardial tolerance to mechanical actuation is affected by biomaterial characteristics.


Journal Article

Direct mechanical ventricular actuation (DMVA) uses a pressure regulated heart cup, fabricated from silicone rubber (SR) for mechanical massage of the heart. Because DMVA has demonstrated potential for long-term circulatory support, investigations are currently exploring the use of more durable materials for fabricating DMVA heart cups. This study assessed the acute effects of heart cups fabricated from SR versus polyurethane (PU) on the myocardium. Dogs (n - 18) received DMVA for 4 hr of ventricular fibrillation (VF) using either SR (n = 10) or PU (n = 8) cups. Microspheres were used to determine perfusion during sinus rhythm (control) and at 2 and 4 hr of support. After support, myocardial biopsies were assayed for high energy phosphate content. Results demonstrated that PU cups required relatively frequent adjustments in drive line parameters that were likely due to material softening during PU cup support. Both PU and SR cups achieved similar hemodynamics during 4 hr of support. Myocardial perfusion, however, demonstrated a marked hyperemia at 4 hr of PU versus SR cup support. Regional high energy phosphate content was significantly decreased in hearts supported by PU versus SR cups. These results suggest that the relatively compliant characteristics of SR materials are important for achieving effective DMVA support without injuring the myocardium.

Full Text

Duke Authors

Cited Authors

  • Anstadt, MP; Perez-Tamayo, RA; Banit, DM; Walthall, HP; Cothran, RL; Abdel-Aleem, S; Anstadt, GL; Jones, PL; Lowe, JE

Published Date

  • July 1994

Published In

Volume / Issue

  • 40 / 3

Start / End Page

  • M329 - M334

PubMed ID

  • 8555534

Pubmed Central ID

  • 8555534

International Standard Serial Number (ISSN)

  • 1058-2916

Digital Object Identifier (DOI)

  • 10.1097/00002480-199407000-00018


  • eng

Conference Location

  • United States