Louie E K, Bieniarz T, Moore A M, Levitsky S
Section of Cardiology, Loyola University Medical Center, Maywood, Illinois.
J Am Coll Cardiol. 1990 Dec;16(7):1617-24. doi: 10.1016/0735-1097(90)90311-c.
Patients undergoing valvulectomy for isolated tricuspid valve endocarditis offer the unique opportunity to study the effects of acquired right ventricular volume overload on left ventricular filling in persons free of pulmonary hypertension and preexisting left heart disease. Eleven patients who had undergone total or partial removal of the tricuspid valve were compared with 11 age-matched control subjects; Doppler echocardiographic techniques were used to quantify changes in left ventricular filling and to relate them to changes in left ventricular and left atrial geometry caused by right ventricular and right atrial distension. The late diastolic fractional transmitral flow velocity integral, a measure of the left atrial contribution to left ventricular filling, was significantly decreased in patients undergoing tricuspid valvulectomy compared with control subjects (0.22 +/- 0.11 versus 0.32 +/- 0.09; p less than 0.04). Severe tricuspid regurgitation in these patients resulted in marked right atrial distension, reversal of the normal interatrial septal curvature and compression of the left atrium such that left atrial area was significantly smaller than in control subjects (5.9 +/- 2.2 versus 8.6 +/- 1.2 cm2/m2; p less than 0.005). Acting as a receiving chamber, the left ventricle was maximally compressed by the volume-overloaded right ventricle in late diastole, coincident with the timing of atrial systole, resulting in a significant increase in the left ventricular eccentricity index compared with that in control subjects (1.35 +/- 0.14 versus 1.03 +/- 0.1; p less than 0.001). Thus, right ventricular volume overload due to severe tricuspid regurgitation results in left heart geometric alterations that decrease left atrial preload, impair left ventricular receiving chamber characteristics and reduce the atrial contribution to total left ventricular filling.
因单纯三尖瓣心内膜炎接受瓣膜切除术的患者提供了一个独特的机会，可用于研究在无肺动脉高压和既往左心疾病的人群中，获得性右心室容量超负荷对左心室充盈的影响。将11例接受三尖瓣全部或部分切除的患者与11例年龄匹配的对照受试者进行比较；采用多普勒超声心动图技术量化左心室充盈的变化，并将其与右心室和右心房扩张引起的左心室和左心房几何形状变化相关联。与对照受试者相比，接受三尖瓣瓣膜切除术的患者舒张晚期经二尖瓣血流速度积分（衡量左心房对左心室充盈的贡献）显著降低（0.22±0.11对0.32±0.09；p<0.04）。这些患者的严重三尖瓣反流导致明显的右心房扩张、正常房间隔曲率逆转和左心房受压，使得左心房面积显著小于对照受试者（5.9±2.2对8.6±1.2 cm²/m²；p<0.005）。作为一个接纳腔室，左心室在舒张晚期被容量超负荷的右心室最大程度地压缩，与心房收缩的时间一致，导致与对照受试者相比，左心室偏心指数显著增加（1.35±0.14对1.03±0.1；p<0.001）。因此，严重三尖瓣反流导致的右心室容量超负荷会引起左心几何形状改变，从而降低左心房前负荷，损害左心室接纳腔室特性，并减少心房对左心室总充盈的贡献。
