Mitral inertance in humans: critical factor in Doppler estimation of transvalvular pressure gradients.
Mitral inertance in humans: critical factor in Doppler estimation of transvalvular pressure gradients.
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人类二尖瓣惯性：多普勒估计跨瓣压力梯度的关键因素。
DOI：
10.1152/ajpheart.2001.280.3.h1340
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Thomas,JD
中科院分区：
文献类型：
--
作者：
Nakatani,S;Firstenberg,MS;Greenberg,NL;Vandervoort,PM;Smedira,NG;McCarthy,PM;Thomas,JD
正常二尖瓣的压力-速度关系近似为伯努利方程ΔP = 1/2 ρΔv2+M·dv/dt，其中ΔP是房室压差，ρ是血液密度，相对于二尖瓣流速，Mi是二尖瓣惯性。尽管在评估二尖瓣血流的跨瓣压差时它是必不可少的，但人们对该术语的理解却很少。我们使用经食管超声心动图测量 100 次心跳（8 名患者）术中高保真左心房和心室压力以及同步二尖瓣血流速度。我们通过 = ∫(ΔP−½ · ρv2)dt/∫(dv/dt)dt 计算平均二尖瓣惯性 ()，并评估惯性项对二尖瓣压力-流量关系的影响。范围从 1.03 到 5.96 g/cm2（平均值 = 3.82 ± 1.22 g/cm2）。根据简化伯努利方程（ΔP = ½ · ρv2）计算的 ΔP 滞后（44 ± 11 ms）并低估了实际峰值压力（2.3 ± 1.1 mmHg）。与左心室收缩压（r= -0.68，P< 0.0001）和二尖瓣压力梯度（r= 0.65，P< 0.0001）相关。由于二尖瓣惰性导致速度明显滞后于实际压力梯度，因此在评估舒张期充盈和正常二尖瓣的压力差时需要考虑这一点。
The pressure-velocity relationship across the normal mitral valve is approximated by the Bernoulli equation ΔP = ½ ρΔv2+M· dv/dt, where ΔP is the atrioventricular pressure difference, ρ is blood density,vis transmitral flow velocity, andMis mitral inertance. AlthoughMis indispensable in assessing transvalvular pressure differences from transmitral flow, this term is poorly understood. We measured intraoperative high-fidelity left atrial and ventricular pressures and simultaneous transmitral flow velocities by using transesophageal echocardiography in 100 beats (8 patients). We computed mean mitral inertance () by= ∫(ΔP−½ · ρv2)dt/∫(dv/dt)dtand we assessed the effect of the inertial term on the transmitral pressure-flow relation.ranged from 1.03 to 5.96 g/cm2(mean = 3.82 ± 1.22 g/cm2). ΔP calculated from the simplified Bernoulli equation (ΔP = ½ · ρv2) lagged behind (44 ± 11 ms) and underestimated the actual peak pressures (2.3 ± 1.1 mmHg).correlated with left ventricular systolic pressure (r= −0.68,P< 0.0001) and transmitral pressure gradients (r= 0.65,P< 0.0001). Because mitral inertance causes the velocity to lag significantly behind the actual pressure gradient, it needs to be considered when assessing diastolic filling and the pressure difference across normal mitral valves.