Computer simulation of coronary flow waveforms during caval occlusion

Area of Science:

• Cardiovascular physiology
• Computational modeling
• Biomedical engineering

Background:

• Mathematical modeling aids in extracting physiological data from complex cardiovascular experiments.
• Accurate simulation of the cardiovascular system is crucial for understanding heart function.

Purpose of the Study:

• To reproduce systemic and coronary measurements from in vivo pig experiments using a computer simulator.
• To validate a lumped parameter model of coronary circulation within a larger cardiovascular model.

Main Methods:

• Monitored coronary blood flow, aortic pressure, and ventricular pressure/volume in pigs.
• Developed a cardiovascular simulator (CARDIOSIM) with a multi-branching coronary model and lumped parameter systemic/pulmonary circulation models.
• Simulated Starling's law using a variable elastance model.

Main Results:

• Presented comparable left ventricular pressure-volume loops between experimental and simulated data during caval occlusion.
• Demonstrated successful reproduction of coronary flow-aortic pressure loops and instantaneous coronary blood flow waveforms.
• The model accurately replicated the profound shape deformation of the coronary flow signal observed in vivo.

Conclusions:

• The lumped parameter model effectively reproduces cardiovascular changes during caval occlusion.
• The coronary loop shape can serve as a sensor for ventricular mechanics in various conditions.
• This model offers a novel tool for investigating determinants of myocardial perfusion.