Analysis of Energy and Pressure in the Sinus with Different Blood Pressures after Bioprosthetic Aortic Valve Replacement.

Abstract

Purpose: To investigate the effect of changing systolic and diastolic blood pressures (SBP and DBP, respectively) on sinus flow and valvular and epicardial coronary flow dynamics after TAVR and SAVR.

Methods: SAPIEN 3 and Magna valves were deployed in an idealized aortic root model as part of a pulse duplicating left heart flow loop simulator. Different combinations of SBP and DBP were applied to the test setup and the resulting change in total coronary flow from baseline (120/60 mmHg), effective orifice area (EOA), and left ventricular (LV) workload, with each combination, was assessed. In addition, particle image velocimetry was used to assess the Laplacian of pressure ( ${\nabla }^2\text{P}$ ) in the sinus, coronary and main flow velocities, the energy dissipation rate (EDR) in the sinus and the LV workload.

Results: This study shows that under an elevated SBP, there is an increase in the total coronary flow, EOA, LV workload, peak velocities downstream of the valve, ${\nabla }^2\text{P}$ , and EDR. With an elevated DBP, there was an increase in the total coronary flow and ${\nabla }^2\text{P}$ . However, EOA and LV workload decreased with an increase in DBP, and EDR increased with a decrease in DBP.

Conclusions: Blood pressure alters the hemodynamics in the sinus and downstream flow following aortic valve replacement, potentially influencing outcomes in some patients.