Stoddard M F, Labovitz A J, Pearson A C
Cardiology Division, University of Louisville, Kentucky.
Echocardiography. 1992 Jul;9(4):387-406. doi: 10.1111/j.1540-8175.1992.tb00483.x.
The role of Doppler echocardiography of transmitral filling velocities in the assessment of diastolic function in man has not been adequately defined. It is now appreciated that multiple interacting factors such as loading conditions influence the transmitral velocity profile independent of intrinsic left ventricular diastolic function. Extrapolating the status of diastolic function from the transmitral velocity profile is complicated by these factors. The load dependence of ventricular filling has tempered the initial enthusiasm for the clinical application of the Doppler technique. In the present review, studies examining invasive parameters of diastolic function and Doppler indices of diastolic filling are discussed to gain greater insight and understanding of the role of Doppler echocardiography in the noninvasive assessment of diastolic function. These studies have demonstrated a relatively consistent influence of left ventricular relaxation, chamber stiffness, and left atrial pressure on the transmitral velocity filling profile. Impairment of relaxation impedes early filling and may result in a compensatory increase in atrial contribution to filling. An independent decrease in left atrial pressure from altered loading conditions may also reduce filling in early diastole. Increased left ventricular chamber stiffness (i.e., noncompliant left ventricle) impairs atrial contribution to filling and may enhance early filling. Theoretically, reduced left atrial contractility may decrease atrial contribution to filling. Pulmonic vein flow demonstrating increased retrograde flow during atrial systole helps to exclude impaired left atrial contractility. An increased left atrial pressure from altered loading conditions may also augment early filling. Therefore, an invasive or clinical assessment of left atrial pressure as being increased, decreased, or normal greatly aids in the interpretation of the transmitral filling velocity profile when inferences on the status of diastolic function are being made. Diastolic dysfunction is likely when a given pattern of filling cannot be explained on the basis of left atrial pressure. In situations where reasonable estimates on the status of left atrial pressure cannot be done, striking alterations in the transmitral velocity filling profile may be useful.
经二尖瓣血流速度的多普勒超声心动图在评估人类舒张功能中的作用尚未得到充分界定。现在人们认识到，诸如负荷条件等多种相互作用的因素会独立于左心室固有舒张功能而影响经二尖瓣速度曲线。这些因素使得从经二尖瓣速度曲线推断舒张功能状态变得复杂。心室充盈的负荷依赖性削弱了人们最初对多普勒技术临床应用的热情。在本综述中，将讨论检查舒张功能的有创参数和舒张期充盈的多普勒指标的研究，以更深入地了解和认识多普勒超声心动图在舒张功能无创评估中的作用。这些研究表明，左心室舒张、心室僵硬度和左心房压力对经二尖瓣速度充盈曲线有相对一致的影响。舒张功能受损会阻碍早期充盈，并可能导致心房对充盈的代偿性增加。由于负荷条件改变导致的左心房压力独立降低也可能减少舒张早期的充盈。左心室腔僵硬度增加（即顺应性降低的左心室）会损害心房对充盈的贡献，并可能增强早期充盈。理论上，左心房收缩力降低可能会减少心房对充盈的贡献。肺静脉血流在心房收缩期显示逆行血流增加有助于排除左心房收缩功能受损。由于负荷条件改变导致的左心房压力增加也可能增强早期充盈。因此，在推断舒张功能状态时，对左心房压力升高、降低或正常进行有创或临床评估，对解释经二尖瓣充盈速度曲线有很大帮助。当某种特定的充盈模式无法基于左心房压力来解释时，舒张功能障碍很可能存在。在无法对左心房压力状态进行合理估计的情况下，经二尖瓣速度充盈曲线的显著改变可能会有所帮助。
