The effect of valve orientation during aortic valve replacement (AVR) with the Medtronic Hall (MH) tilting disc valve on transvalvuler pressure gradients was evaluated. 30 patients (pts) undergoing isolated AVR received a MH which was oriented so that the greater opening of the valve faced the non coronary aortic sinus. There were 12 male and 8 female pts in this group with a mean age of 59 +/- 5.2 years. An echocardiographic examination was performed 6 days after the operation and resting ...