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

Abstract

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. 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 ( <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msup><mrow><mi>∇</mi></mrow> <mn>2</mn></msup> <mtext>P</mtext></mrow> </math> ) in the sinus, coronary and main flow velocities, the energy dissipation rate (EDR) in the sinus and the LV workload. 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, <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msup><mrow><mi>∇</mi></mrow> <mn>2</mn></msup> <mtext>P</mtext></mrow> </math> , and EDR. With an elevated DBP, there was an increase in the total coronary flow and <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <msup><mrow><mi>∇</mi></mrow> <mn>2</mn></msup> <mtext>P</mtext></mrow> </math> . However, EOA and LV workload decreased with an increase in DBP, and EDR increased with a decrease in DBP. Blood pressure alters the hemodynamics in the sinus and downstream flow following aortic valve replacement, potentially influencing outcomes in some patients.