In an in vitro model of aortic stenosis, computational fluid dynamics provided a small but significant improvement over the simplified Bernoulli equation for predicting pressure gradients across a 0.52cm2 orifice (p < 0.01).
Does computational fluid dynamics improve the accuracy of maximum pressure gradient estimation compared to the simplified Bernoulli equation in an in vitro model of aortic stenosis?
Computational fluid dynamics may offer improved accuracy over the simplified Bernoulli equation for estimating pressure gradients in severe aortic stenosis.
p-value: p=<0.01
BACKGROUND: The assessment of the severity of aortic valve stenosis is done by either invasive catheterization or non-invasive Doppler Echocardiography in conjunction with the simplified Bernoulli equation. The catheter measurement is generally considered more accurate, but the procedure is also more likely to have dangerous complications. OBJECTIVE: The focus here is on examining computational fluid dynamics as an alternative method for analyzing the echo data and determining whether it can provide results similar to the catheter measurement. METHODS: An in vitro heart model with a rigid orifice is used as a first step in comparing echocardiographic data, which uses the simplified Bernoulli equation, catheterization, and echocardiographic data, which uses computational fluid dynamics (i.e., the Navier-Stokes equations). RESULTS: For a 0.93cm(2) orifice, the maximum pressure gradient predicted by either the simplified Bernoulli equation or computational fluid dynamics was not significantly different from the experimental catheter measurement (p > 0.01). For a smaller 0.52cm(2) orifice, there was a small but significant difference (p < 0.01) between the simplified Bernoulli equation and the computational fluid dynamics simulation, with the computational fluid dynamics simulation giving better agreement with experimental data for some turbulence models. CONCLUSION: For this simplified, in vitro system, the use of computational fluid dynamics provides an improvement over the simplified Bernoulli equation with the biggest improvement being seen at higher valvular stenosis levels.
Heys et al. (Fri,) conducted a other in Aortic valve stenosis (in vitro model). Computational fluid dynamics (CFD) vs. Simplified Bernoulli equation and experimental catheter measurement was evaluated on Maximum pressure gradient across the orifice (p=<0.01). In an in vitro model of aortic stenosis, computational fluid dynamics provided a small but significant improvement over the simplified Bernoulli equation for predicting pressure gradients across a 0.52cm2 orifice (p < 0.01).