De Paulis R, Sommariva L, De Matteis G M, Polisca P, Tomai F, Bassano C, Penta de Peppo A, Chiariello L
Department of Cardiac Surgery, University of Rome, Tor Vergata, Italy.
J Heart Valve Dis. 1996 Nov;5 Suppl 3:S339-43.
Optimal hemodynamic performances are of paramount importance when implanting a mechanical valve in patients with a small aortic annulus. A Doppler echocardiographic study was performed to compare the hemodynamic performances of small CarboMedics and St. Jude valves.
Twenty-nine patients receiving either a 19 mm (n = 10) or a 21 mm (n = 10) CarboMedics valve or a 19 mm (n = 9) St. Jude Med HP valve were evaluated. A Doppler echocardiographic study was performed at rest and two minutes after treadmill exercise with the Bruce protocol. Peak and mean gradients across the valve were estimated; effective orifice area, performance index and discharge coefficient were calculated. Heart rate, blood pressure and cardiac output were all significantly increased with exercise.
Peak and mean gradients at rest were significantly higher (p < 0.05) in the 19 mm CarboMedics valve (40.2 +/- 15 mmHg and 22.6 +/- 9 mmHg, respectively) when compared either with 21 mm CarboMedics valve (27.6 +/- 6.8 mmHg and 14.2 +/- 3.4 mmHg, respectively) or with the 19 mm St. Jude HP valve (23.6 +/- 10.4 mmHg and 13.6 +/- 5 mmHg, respectively). Peak and mean gradients were not modified with exercise for the 19 mm CarboMedics valve and significantly increased for the 21 mm CarboMedics and the 19 mm St. Jude HP valves. Although these values were still higher in the 19 mm CarboMedics valve, they did not reach the level of statistical significance when compared with the other two valve groups.
The 19 mm St. Jude HP valve shows hemodynamic performances at rest that are similar to those of the 21 mm CarboMedics valve and superior to those of the 19 mm CarboMedics valve. With exercise both sizes of the CarboMedics valve show an in vivo discharge coefficient close to one, testifying to a full utilization of the internal orifice area.
在主动脉瓣环较小的患者中植入机械瓣膜时，最佳血流动力学性能至关重要。进行了一项多普勒超声心动图研究，以比较小型CarboMedics瓣膜和圣犹达瓣膜的血流动力学性能。
对29例接受19mm（n = 10）或21mm（n = 10）CarboMedics瓣膜或19mm（n = 9）圣犹达Med HP瓣膜的患者进行评估。采用Bruce方案，在静息状态下以及跑步机运动两分钟后进行多普勒超声心动图研究。估计瓣膜两端的峰值和平均压差；计算有效瓣口面积、性能指数和流量系数。运动后心率、血压和心输出量均显著增加。
与21mm CarboMedics瓣膜（分别为27.6±6.8mmHg和14.2±3.4mmHg）或19mm圣犹达HP瓣膜（分别为23.6±10.4mmHg和13.6±5mmHg）相比，19mm CarboMedics瓣膜静息时的峰值和平均压差显著更高（p < 0.05）。19mm CarboMedics瓣膜运动时峰值和平均压差未改变，而21mm CarboMedics瓣膜和19mm圣犹达HP瓣膜显著增加。尽管19mm CarboMedics瓣膜的这些值仍较高，但与其他两组瓣膜相比未达到统计学显著水平。
19mm圣犹达HP瓣膜静息时的血流动力学性能与21mm CarboMedics瓣膜相似，优于19mm CarboMedics瓣膜。运动时，两种尺寸的CarboMedics瓣膜在体内的流量系数均接近1，表明内部瓣口面积得到充分利用。
