Wave intensity analysis of para-aortic counterpulsation

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Hemodynamics

Background:

• The intra-aortic balloon pump (IABP) is a standard counterpulsation device.
• Optimizing counterpulsation efficacy requires precise timing and understanding of wave dynamics.
• A novel para-aortic blood pump (PABP) has been developed.

Purpose of the Study:

• To compare the hemodynamic effects of PABP and IABP using wave intensity analysis (WIA).
• To delineate and maximize the efficacy of the PABP.
• To assess the impact of PABP timing on aortic and coronary blood flow.

Main Methods:

• Acute porcine model with eight pigs, randomly assigned to IABP or PABP groups.
• Measurement of aortic and coronary pressure and velocity.
• Wave intensity analysis (WIA) applied to pressure and flow data.
• Optimization of PABP deflation timing relative to the R-wave.

Main Results:

• PABP, like IABP, uses backward waves to augment aortic and coronary flow.
• PABP's nonocclusive nature avoids coronary blood steal seen with IABP.
• Optimized PABP timing improved coronary perfusion by reducing regurgitation, despite potential decreases in Total Accelerating Wave Intensity (TAWI).

Conclusions:

• PABP demonstrates potential for improved counterpulsation efficacy over IABP, particularly in preserving coronary perfusion.
• Wave intensity analysis is a sensitive tool for evaluating counterpulsation strategies.
• PABP's nonocclusive design offers distinct hemodynamic advantages, especially when timing is optimized.