Effects of ischemia on left ventricular regional function in the conscious dog.

Published

Journal Article

Three-dimensional regional geometry of the left ventricle was assessed in seven conscious trained dogs chronically implanted with pulse-transit ultrasonic-dimension transducers. Minor and major axis segment lengths and wall thickness were measured in the distribution of the left anterior descending coronary artery; transmural pressure (TMP) was measured with high-fidelity micromanometers. Data were recorded during the control state and following 30 s and 30 min of ischemia. Dimensions were normalized as a fractional extension from the length at zero TMP (Lo). Dynamic cube mass was calculated and remained constant throughout the cardiac cycle in both control and ischemic states, although the calculated mass decreased by an average of 5% during ischemia. The slope constants of the exponential diastolic pressure-dimension relationship increased following acute coronary occlusion indicating increases in regional myocardial stiffness with increasing periods of ischemia. Coronary occlusion also was associated with an increase in the Lo measurements in the major and minor axis dimensions and a decrease in the wall thickness Lo. These findings are consistent with an ischemia-induced plastic deformation of the regional myocardium defined as creep. Thus, acute ischemia results in a decline of regional systolic function, induces myocardial creep, and causes an immediate and sustained increase in regional myocardial stiffness.

Full Text

Duke Authors

Cited Authors

  • Edwards, CH; Rankin, JS; McHale, PA; Ling, D; Anderson, RW

Published Date

  • March 1, 1981

Published In

Volume / Issue

  • 240 / 3

Start / End Page

  • H413 - H420

PubMed ID

  • 7212083

Pubmed Central ID

  • 7212083

Electronic International Standard Serial Number (EISSN)

  • 2163-5773

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajpheart.1981.240.3.h413

Language

  • eng