Extent, determinants and clinical importance of pressure recovery in patients with aortic valve stenosis

Aims In experimental studies the recovery of pressure distal to stenotic valve orifices has been well described. We evaluated the extent, determinants, and clinical importance of pressure recovery in patients with aortic valve stenosis. Methods and Results The study was performed in 37 patients with aortic valve stenosis, in whom cardiac catheterization was performed and left ventricular and aortic pressures were determined using a high-fidelity multi-tip micromanometer catheter. To register the pressure waveforms accurately the catheter was positioned so that the proximal micromanometer was in the left ventricle, the second at the site of minimal pressure in the vena contracta, and the third (the most distal) in the ascending aorta 16 cm further downstream. The amount of pressure recovery within the ascending aorta was up to 44% of the maximal pressure drop. The index pressure recovery was directly correlated to the Gorlin-derived aortic valve area (r=0.80) and indirectly correlated to the ratio of aortic valve area and the cross-sectional area of the ascending aorta. Conclusions This clinical study confirmed experimental data, that index pressure recovery is dependent on the ratio of the effective valve area and the cross-sectional area of the ascending aorta. Pressure recovery may need to be considered in patients with mild to moderate aortic stenosis and with a small cross-sectional area of the ascending aorta.