Vanoverschelde J L, Essamri B, Michel X, Hanet C, Cosyns J R, Detry J M, Wijns W
Division of Cardiology, University of Louvain Medical School, Brussels, Belgium.
J Am Coll Cardiol. 1992 Oct;20(4):813-21. doi: 10.1016/0735-1097(92)90178-p.
The aim of the present study was to evaluate the hemodynamic and volume correlates of early diastolic filling and isovolumetric relaxation in patients with aortic stenosis.
Left ventricular diastolic relaxation and filling have been found to be heterogeneous in patients with aortic stenosis. Potential mechanisms underlying this heterogeneity include individual differences in the severity of muscle hypertrophy or systolic dysfunction, or both, in the presence and severity of mitral regurgitation and in the level of left atrial pressure.
Right (fluid-filled) and left (high fidelity micromanometer) ventricular pressures, left ventricular volumes (contrast angiography) and transmitral inflow dynamics (Doppler echocardiography) were measured in 17 patients with isolated severe aortic stenosis (valve area less than 0.75 cm2). Measurements included left ventricular end-diastolic and end-systolic volumes, left ventricular ejection fraction, peak positive and negative first derivative of left ventricular pressure (dP/dt), the time constant of isovolumetric relaxation (tau), left ventricular end-diastolic pressure, left ventricular mass, left ventricular end-systolic stress, mean capillary wedge pressure and peak early (E) and late (A) transmitral filling velocities. Patients were subclassified according to left ventricular ejection performance at rest and mean capillary wedge pressure.
Patients with normal ejection performance and normal mean capillary wedge pressure had a normal rate of isovolumetric left ventricular pressure decay and an abnormal diastolic filling pattern, with diastolic filling occurring primarily during atrial systole. In contrast, in patients with systolic dysfunction and elevated mean capillary wedge pressure, isovolumetric pressure decay was prolonged and diastolic filling occurred essentially during the rapid filling period, with reduced atrial contribution to left ventricular filling and a short isovolumetric relaxation period. Stepwise multiple linear regression analysis identified two variables as independent predictors of transmitral velocity profile and three variables independently predictive of the rate of left ventricular pressure decay. The single most important predictor of transmitral filling pattern was the pulmonary capillary wedge pressure (p less than 0.0001), followed by the left ventricular peak negative dP/dt (p = 0.002). The single most powerful predictor of the rate of reduction in left ventricular pressure was left ventricular mass index (p less than 0.0001), followed by end-systolic volume index (p = 0.0002) and left ventricular peak negative dP/dt (p = 0.0029).
In patients with aortic stenosis, left ventricular filling is essentially determined by left atrial pressure, whereas isovolumetric relaxation more closely depends on the severity of muscle hypertrophy and chamber dilation.
本研究旨在评估主动脉瓣狭窄患者舒张早期充盈和等容舒张的血流动力学及容量相关性。
已发现主动脉瓣狭窄患者左心室舒张期松弛和充盈存在异质性。这种异质性的潜在机制包括肌肉肥厚或收缩功能障碍严重程度的个体差异，或二者兼有，二尖瓣反流的存在及严重程度，以及左心房压力水平。
对17例单纯严重主动脉瓣狭窄（瓣膜面积小于0.75平方厘米）患者测量右心室（充满液体）和左心室（高保真微测压计）压力、左心室容量（造影剂血管造影）及二尖瓣血流动力学（多普勒超声心动图）。测量指标包括左心室舒张末期和收缩末期容量、左心室射血分数、左心室压力的最大正负一阶导数（dP/dt）、等容舒张时间常数（tau）、左心室舒张末期压力、左心室质量、左心室收缩末期应力、平均毛细血管楔压以及二尖瓣早期（E）和晚期（A）充盈峰值速度。根据静息时左心室射血功能和平均毛细血管楔压对患者进行亚分类。
射血功能正常且平均毛细血管楔压正常的患者等容期左心室压力下降速率正常，但舒张期充盈模式异常，舒张期充盈主要发生在心房收缩期。相比之下，收缩功能障碍且平均毛细血管楔压升高的患者等容期压力下降延长，舒张期充盈基本发生在快速充盈期，心房对左心室充盈的贡献减少，等容舒张期缩短。逐步多元线性回归分析确定两个变量为二尖瓣速度曲线的独立预测因子，三个变量为左心室压力下降速率的独立预测因子。二尖瓣充盈模式的最重要单一预测因子是肺毛细血管楔压（p<0.0001），其次是左心室最大负向dP/dt（p = 0.002）。左心室压力下降速率的最有力单一预测因子是左心室质量指数（p<0.0001），其次是收缩末期容量指数（p = 0.0002）和左心室最大负向dP/dt（p = 0.0029）。
在主动脉瓣狭窄患者中，左心室充盈主要由左心房压力决定，而等容舒张更密切地取决于肌肉肥厚和心室扩张的严重程度。
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