Intraoperative hemodynamic evaluation of the Björk-Shiley tilting disc aortic valve.

Intraoperative cardiac output and aortic and left ventricular pressures were measured simultaneously in 15 consecutive patients before and after aortic valve replacement (AVR) with the Björk-Shiley tilting disc valve. The predominant lesion in these patients was aortic stenosis. The following hemodynamic indices were calculated: aortic valve area (AVA), determined by Gorlin's formula, effective orifice area, and effective area index. Their applicability as hemodynamic criteria of the immediate hemodynamic performance of the replaced valve is discussed. By every criterion, AVR greatly improved the hemodynamic performance. The effective area index seemed more suitable than the other indices for the intraoperative hemodynamic evaluation of the replaced aortic valve.