Related Experiment Videos
Graded myocardial ischemia is associated with a decrease in diastolic distensibility of the remote nonischemic
S C Marsch1, V A Wanigasekera, W A Ryder
1Nuffield Department of Anesthetics, University of Oxford, Radcliffe Infirmary, England, United Kingdom.
Journal of the American College of Cardiology
|September 1, 1993
Summary
Myocardial ischemia reduces the distensibility of both the affected heart muscle and healthy areas. This study quantifies changes in chamber and myocardial stiffness during graded ischemia.
Area of Science:
- Cardiovascular Physiology
- Myocardial Ischemia Research
- Cardiac Mechanics
Background:
- Ventricular distensibility significantly impacts left ventricular end-diastolic pressure.
- Limited research exists on how graded myocardial ischemia affects regional distensibility in both ischemic and non-ischemic areas.
- Understanding these effects is crucial for managing cardiac function during ischemic events.
Purpose of the Study:
- To investigate alterations in regional distensibility within ischemic and remote non-ischemic myocardial segments.
- To quantify the impact of graded myocardial ischemia on cardiac mechanics.
- To assess changes in chamber and myocardial stiffness.
Main Methods:
- Utilized sonomicrometry in anesthetized dogs to measure left ventricular pressure and segment length.
- Induced regional ischemia through stepwise blood withdrawal and infusion.
- Assessed regional distensibility using pressure-length, pressure-strain, and force-strain relations at end-diastole.
Main Results:
- Ischemic segments showed a twofold increase in chamber and myocardial stiffness constants.
- Non-ischemic segments exhibited a 50% increase in chamber and myocardial stiffness constants.
- Both ischemic and remote non-ischemic myocardium demonstrated reduced distensibility.
Conclusions:
- Regional myocardial ischemia significantly decreases the distensibility of the affected myocardium.
- Remote, non-ischemic myocardium also experiences a reduction in distensibility.
- These findings highlight the widespread impact of ischemia on cardiac mechanics.