Hoffmann A, Weiss P, Dubach P, Burckhardt D
Division of Cardiology, University Hospital, Basel, Switzerland.
Chest. 1990 Nov;98(5):1165-8. doi: 10.1378/chest.98.5.1165.
Doppler echocardiography was used to study the function of bioprosthetic heart valves by noninvasive means in 32 patients aged 29 to 72 years at various postoperative intervals. There were 24 Ionescu-Shiley, four Hancock, and four Carpentier-Edwards prostheses, 19 in the aortic and 13 in the mitral position. Initial studies were performed at a mean of 2.3 years after implantation and were repeated one, two, and three years thereafter. Flow velocities in the mitral orifice, left ventricular outflow tract, and ascending aorta, as well as mitral pressure half-time, were measured from pulsed-wave or continuous-wave Doppler recordings. Mitral and aortic valve areas and aortic pressure gradients were calculated. In aortic prostheses the valve area decreased and pressure gradient increased progressively in relation to the time from implantation. The mean value (+/- SD) of the aortic valve area was 67 +/- 17 percent of the manufacturer's nominal value at the first examination and 57 +/- 20 percent one year later, 51 +/- 14 percent two years later, and 46 +/- 11 percent three years later (overall differences, p less than 0.01). In mitral prostheses, reduction of the valve area was not related to the time from implantation. The mean mitral valve area was 45 +/- 12 percent of the nominal value at rest and increased to 68 +/- 18 percent during exercise at a mean of 45 months after implantation. There was no change in these values at the one-year repeat study. It is concluded that in a population with predominantly pericardial bioprostheses, (1) aortic tissue prostheses showed a progressive functional deterioration demonstrable by Doppler echocardiography, most probably due to degenerative changes; and (2) in mitral tissue prostheses, there was no significant reduction of orifice area in relation to time from implantation. Reduction of mitral valve areas may, to some extent, reflect a less than full opening at rest.
采用多普勒超声心动图对32例年龄在29至72岁之间的患者进行无创性研究，观察不同术后时期生物人工心脏瓣膜的功能。其中有24个Ionescu-Shiley瓣膜、4个Hancock瓣膜和4个Carpentier-Edwards瓣膜，19个位于主动脉瓣位，13个位于二尖瓣位。首次研究在植入后平均2.3年进行，此后1年、2年和3年重复进行。通过脉冲波或连续波多普勒记录测量二尖瓣口、左心室流出道和升主动脉的血流速度，以及二尖瓣压力减半时间。计算二尖瓣和主动脉瓣面积以及主动脉压力阶差。在主动脉瓣人工瓣膜中，瓣膜面积随植入时间的延长逐渐减小，压力阶差逐渐增大。首次检查时主动脉瓣面积的平均值（±标准差）为制造商标称值的67±17%，1年后为57±20%，2年后为51±14%，3年后为46±11%（总体差异，p<0.01）。在二尖瓣人工瓣膜中，瓣膜面积的减小与植入时间无关。二尖瓣平均面积在植入后平均45个月静息时为标称值的45±12%，运动时增加到68±18%。在1年重复研究时这些值没有变化。得出结论，在以心包生物人工瓣膜为主的人群中，（1）主动脉组织人工瓣膜显示出功能逐渐恶化，多普勒超声心动图可证实，很可能是由于退行性改变；（2）在二尖瓣组织人工瓣膜中，瓣口面积与植入时间无关，无明显减小。二尖瓣面积的减小在一定程度上可能反映静息时开放不完全。
