Doppler echocardiography evaluation of the hemodynamic performance of the Lillehei-Kaster and Medtronic Hall valves in aortic position

To establish the range of normal values by Doppler echocardiography of the parameters inherent to the hemodynamic performance of the Lillehei-Kaster (LK) and Medtronic Hall (MH) prosthetic valves (V), in the 23 mm (LKV-16, MHV-23) and 25 mm (LKV-18, MHV-25) outer diameter valves, in the aortic position. Doppler echocardiography was performed in 32 asymptomatic patients, with normally functioning prosthetic aortic valves (8 of each type). The peak velocity of aortic jet was 3.13 +/- 0.46 m/sec for the LKV-16, 2.76 +/- 0.31 m/sec for the MHV-23, 2.82 +/- 0.48 m/sec for the LKV-18 and 2.43 +/- 0.36 m/sec for the MHV-25. The maximal pressure gradient was 39.84 +/- 12.05 mmHg for the LKV-16, 30.70 +/- 6.80 mmHg for the MHV-23, 32.60 +/- 10.75 mmHg for the LKV-18 and 24.11 +/- 6.70 mmHg for the MHV-25. The mean pressure gradient was 24.25 +/- 7.09 mmHg for the LKV-16, 18.50 +/- 4.41 mmHg for the MHV-23, 18.21 +/- 6.95 mmHg for the LKV-18 and 13.57 +/- 4.17 mmHg for the MHV-25. The valve effective orifice area, considering the left ventricle outflow area determined by two-dimensional echocardiography in the continuity equation, was 0.62 +/- 0.13 cm2 for the LKV-16, 1.05 +/- 0.21 cm2 for the MHV-23, 0.98 +/- 0.22 cm2 for the LKV-18 and 1.36 +/- 0.36 cm2 for the MHV-25. Considering the left ventricle outflow area equivalent to the valve sewing ring area, the valve effective orifice area was 1.40 +/- 0.23 cm2 for the LKV-16, 1.65 +/- 0.19 cm2 for the MHV-23, 1.91 +/- 0.43 cm2 for the LKV-18 and 2.37 +/- 0.56 cm2 for the MHV-25. The Doppler velocity index was 0.34 +/- 0.05 for the LKV-16, 0.40 +/- 0.04 for the MHV-23, 0.39 +/- 0.09 for the LKV-18 and 0.49 +/- 0.11 for the MHV-25. Significant hemodynamic performance superiority of the MHV over the LKV was registered, indicating that the small LKV (LKV-16 or smaller) should be avoided.