CarboMedics瓣膜二尖瓣置换术后多普勒超声心动图评价

目的 应用超声心动图评价二尖瓣置换术后2年CarboMedics(CM)瓣膜的功能,并比较压力半降时间(PHT)法和连续方程(CON)法计算的有效瓣口面积(EOA).方法 49例应用CM瓣膜行单纯二尖瓣置换手术的患者进入本研究.置换的CM瓣膜为:25 mm 13例,27 mm 36例.术后2年行经胸彩色超声心动图检查,测量及计算指标:左心室射血分数(LVEF),左室每搏输出量(SV),PHT,二尖瓣舒张早期峰值流速(E velocity),平均跨瓣压差(MG),二尖瓣人工瓣膜/左室流出道血流时间速率积分比率(TVIMVP/TVILVOT).以PHT<130 ms、E velocity<2.0 m/s及TVIMVP/TVILVOT<2.2为评价人工瓣膜功能正常的标准.结果 同时符合E velocity<2 m/s、TVIMVP/TVILVOT<2.2及PHT<130 ms者26例(53.1%).采用25 mm瓣膜或采用27 mm瓣膜患者的PHT、MG、TVIMVP/TVILVOT、EOA之间的差异无统计学意义(P>0.05),但采用25 mm瓣膜患者的E velocity大于采用27 mm瓣膜患者的E velocity(P<0.05),采用PHT法计算的瓣膜的EOA大于CON法计算的相应瓣号瓣膜的EOA(P<0.05). 结论 二尖瓣置换术后2年CM瓣膜功能是可以接受的,这表现在多数患者PHT<130 ms、E velocity<2.0 m/s及TVIMVP/TVILVOT<2.2;对于超过上述范围的患者应加强随访及复查.二尖瓣置换术后采用PHT法计算的瓣膜EOA明显高于CON法计算的瓣膜EOA.

Doppler Echocardiographic Assessment of CarboMedics Prosthesis in Patients with Mitral Valve Replacement

Objective To evaluate the CarboMedics (CM) prosthesis function two years after mitral valve replacement, and to compare the effective orifice area(EOA) calculated by pressure half-time (PHT) method and continuity method (CON). Methods Forty nine patients who underwent isolated mitral valve replacement with a CM prosthesis were recruited in this study, which included 13 cases of 25 mm CM prosthesis and 36 cases of 27 mm CM prosthesis. Two years after the mitral valve replacement, transthoracic echocardiography (TTE) was performed, measuring left ventricular ejection fraction (LVEF), stroke volume mean gradient (SV), PHT, peak early mitral diastolic velocity (E velocity), mean gradient (MG), time-velocity integral of left ventricular outflow tract/time-velocity integral of mitral valve prosthesis (TVI_(MVP)/TVI_(LVOT)). The function of the prosthetic valve was considered normal when PHT <130 ms, E velocity <2. 0 m/s and TVI_(MVP)/TVI_(LVOT)<2. 2. Results More than half (53. 1%) of the patients had normal function of the prosthetic valve. No significant differences were found in PHT, MG, TVI_(MVP)/TVI_(LVOT)>EOA or IEOA between the patients with 25 mm valve and the patients with 27 mm valve (P> 0. 05). But the patients with 25 mm valve had higher E velocity than the patients with 27 mm valve (P <0. 05). The PHT method produced greater EOA than by the CON method (P<0. 05). Conclusion The function of CM prosthesis is acceptable two years after the mitral valve replacement, with most patients having PHT<130 ms, E velocity <2. 0 m/s and TVI_(MVP)/TVI_(LVOT)<2. 2. PHT method produces greater EOA than CON method.