Award article: Microcirculatory Society Award for Excellence in Lymphatic Research: time course of myocardial
Ranjeet M Dongaonkar1, Randolph H Stewart, Christopher M Quick
1Michael E DeBakey Institute, Texas A&M University, College Station, Texas 77843-4466, USA.
Insights
Myocardial edema, or fluid buildup in the heart muscle, causes diastolic stiffness and cardiac dysfunction. This dysfunction persists even after the edema resolves, indicating a lasting impact on heart function.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Heart Failure Research
Background:
- Acute myocardial edema is linked to cardiac dysfunction.
- The resolution of myocardial edema and subsequent cardiac function recovery remain understudied.
- Key parameters like edema resolution time and post-edema cardiac function depression are unknown.
Purpose of the Study:
- To characterize temporal changes in cardiac function during the formation and resolution of acute myocardial edema.
- To investigate the relationship between myocardial edema and diastolic stiffness.
- To determine if cardiac function recovers after myocardial edema resolution.
Main Methods:
- Acute myocardial edema induced in a canine model by elevating coronary sinus pressure for 3 hours.
- Myocardial water content and cardiac function assessed pre-, during, and post-pressure elevation.
- Temporal changes monitored throughout edema formation and resolution phases.
Main Results:
- Myocardial edema accumulation increased diastolic stiffness without affecting systolic properties.
- Edema resolved within 180 minutes after relieving coronary sinus pressure.
- Diastolic stiffness and cardiac function remained significantly compromised post-resolution.
Conclusions:
- Cardiac dysfunction induced by myocardial edema may persist after edema resolution.
- This finding suggests persistent diastolic stiffness as a mechanism for prolonged cardiac dysfunction.
- New imaging techniques for quantifying myocardial edema may aid in detecting and treating this condition.
Objective:
Although the causal relationship between acute myocardial edema and cardiac dysfunction has been established, resolution of myocardial edema and subsequent recovery of cardiac function have not been established. The time to resolve myocardial edema and the degree that cardiac function is depressed after edema resolves are not known. We therefore characterized temporal changes in cardiac function as acute myocardial edema formed and resolved.
Methods:
Acute myocardial edema was induced in the canine model by elevating coronary sinus pressure for three hours. Myocardial water content and cardiac function were determined before and during coronary sinus pressure elevation, and after coronary sinus pressure restoration.
Results:
Although no change in systolic properties was detected, accumulation of water in myocardial interstitium was associated with increased diastolic stiffness. When coronary sinus pressure was relieved, myocardial edema resolved within 180 minutes. Diastolic stiffness, however, remained significantly elevated compared with baseline values, and cardiac function remained compromised.
Conclusions:
The present work suggests that the cardiac dysfunction caused by the formation of myocardial edema may persist after myocardial edema resolves. With the advent of new imaging techniques to quantify myocardial edema, this insight provides a new avenue for research to detect and treat a significant cause of cardiac dysfunction.
