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Flow patterns in three-dimensional left ventricular systolic and diastolic flows determined from computational fluid
1Department of Bio-Medical Engineering, School of High-Technology for Human Welfare, Tokai University, Shizuoka, Japan.
Biorheology
|January 1, 1995
Summary
This study modeled the heart's left ventricle across cardiac cycles. Initial cycles showed velocity variations, but later cycles stabilized, revealing insights into blood flow dynamics and cardiac function.
Area of Science:
- Cardiovascular Physiology
- Biomechanical Modeling
Background:
- Previous research utilized a diastole-cast dog heart model but only analyzed systole.
- A need existed to analyze the complete cardiac cycle, including diastole, and its impact on subsequent cycles.
Purpose of the Study:
- To extend a realistic left ventricle model to include both systole and diastole.
- To investigate the effect of preceding cardiac cycles on subsequent ones.
Main Methods:
- A 3D model of the left ventricle was used, simulating a 40% volume reduction over 0.25s (systole), followed by a 0.25s increase (diastole), and a 0.25s rest period.
- Simulations were run with a 60% ejection fraction.
Main Results:
- Significant variations in maximum velocity (>30%) occurred between the first and second cardiac cycles.
- Velocity vectors increased at the aortic outlet during systole, with most pressure drop in the upper ventricle.
- Diastole exhibited complex vortex formation, potentially explaining turbulent blood flow in the aorta.
Conclusions:
- Cardiac cycle variability diminishes after the initial cycles, suggesting a stabilizing effect.
- Complex diastolic vortices are a key feature of left ventricular function and may contribute to aortic blood flow characteristics.