[Non-invasive determination of pressure gradients of heart valve prostheses using Doppler ultrasound].
Noninvasive measurements of pressure gradients by continuous wave Doppler ultrasound technique were carried out in 40 patients with correctly functioning heart valve prostheses (10 Björk-Shiley in aortic position, 10 Björk-Shiley in mitral, 10 St. Jude Medical in aortic and 10 St. Jude Medical in mitral) and in 10 patients with normal aortic and 10 patients with normal mitral valves. The pressure gradients were slightly but significantly higher in prosthetic than in normal heart valves (p less than 0.005). Pressure gradients in Björk-Shiley prostheses were higher than in St. Jude Medical prostheses both in aortic (18.4 +/- 2.6 vs 9.6 +/- 1.9; p less than 0.01) and in mitral position (8.2 +/- 1.1 vs 5.4 +/- 0.8; p less than 0.05). The pressure gradient was inversely related to valve size in Björk-Shiley prostheses (r = -0.60 for aortic and r = -0.42 for mitral valves; p less than 0.05) but not in St. Jude Medical prostheses. The non-invasive Doppler technique should be useful in the diagnosis of prosthetic valve obstruction.
D001021:Aortic Valve / Q000601:surgery; D006350:Heart Valve Prosthesis; D006801:Humans; D008943:Mitral Valve / Q000601:surgery; D011312:Pressure; D014463:Ultrasonography
Nicht-invasive Bestimmung von Druckgradienten an Herzklappenprothesen mit Doppler-Ultraschall.