Determinants of stroke volume and systolic and diastolic aortic pressure

Area of Science:

• Cardiovascular physiology
• Biomedical engineering
• Mathematical modeling

Background:

• Understanding the determinants of systolic and diastolic pressures and stroke volume is crucial for diagnosing and managing cardiovascular conditions.
• Existing cardiovascular models often involve numerous parameters, complicating analysis and prediction.

Purpose of the Study:

• To identify a minimal set of dimensionless parameters that accurately describe systolic pressure (Ps), diastolic pressure (Pd), and stroke volume (SV).
• To derive empirical analytical expressions for these hemodynamic parameters based on the identified dimensionless variables.

Main Methods:

• Utilized a varying-elastance model for the heart and a three-element windkessel model for the arterial system.
• Applied dimensional analysis to reduce the number of governing parameters.
• Performed sensitivity analysis to determine the most influential dimensionless parameters.

Main Results:

• Identified six dimensionless parameters that describe dimensionless Ps, Pd, and SV.
• Found that Ps/Pv, Pd/Pv, and SV/Vd can be accurately represented by four, three, and three dimensionless parameters, respectively.
• Developed and validated empirical analytical expressions for Ps/Pv, Pd/Pv, and SV/Vd with high correlation to model values (r > 0.987).

Conclusions:

• Aortic systolic and diastolic pressures and stroke volume can be accurately predicted using a limited set of dimensionless parameters.
• The derived analytical expressions provide a simplified yet accurate method for representing cardiovascular function across various conditions.