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Left ventricular diastolic function of the reperfused postischemic donor heart
T Shirai1, M Sunamori, A Suzuki
1Department of Thoracic-Cardiovascular Surgery, Tokyo Medical and Dental University, School of Medicine, Japan.
Surgery Today
|January 1, 1993
Summary
Donor heart preservation impacts relaxation and stiffness. Myocardial calcium (Ca2+) increases with adenosine triphosphate (ATP) depletion, correlating with stiffness and reduced relaxation in preserved hearts.
Area of Science:
- Cardiology
- Biochemistry
- Physiology
Background:
- Hypothermic cardioplegic preservation is standard for donor hearts.
- Understanding biochemical changes during reperfusion is crucial for graft viability.
Purpose of the Study:
- To investigate the relationship between left ventricular diastolic function and myocardial biochemical changes.
- To assess the impact of hypothermic preservation and reperfusion on donor heart function.
Main Methods:
- Isolated canine hearts (n=47) underwent 6-hour hypothermic preservation (5°C).
- Hearts were reperfused normothermically for 2 hours.
- Regression analysis correlated diastolic function parameters with myocardial biochemical concentrations.
Main Results:
- Left ventricular relaxation (max -dp/dt) negatively correlated with stiffness (end-diastolic pressure).
- Myocardial adenosine triphosphate (ATP) concentrations correlated inversely with calcium (Ca2+) levels.
- Increased myocardial Ca2+ was linked to ATP depletion and correlated with increased wall stiffness and impaired ventricular relaxation.
Conclusions:
- Left ventricular relaxation is inversely related to stiffness in preserved donor hearts.
- Elevated myocardial Ca2+ indicates ATP exhaustion and contributes to impaired diastolic function.
- Myocardial ATP levels are critical for maintaining normal ventricular relaxation.