Dragulescu Andreea, Friedberg Mark K, Grosse-Wortmann Lars, Redington Andrew, Mertens Luc
Division of Cardiology, Labatt Family Heart Centre, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Division of Cardiology, Labatt Family Heart Centre, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada; Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada.
J Am Soc Echocardiogr. 2014 Aug;27(8):896-902. doi: 10.1016/j.echo.2014.04.012. Epub 2014 May 17.
Right ventricular (RV) volume overload results in RV dilatation and dysfunction in patients with pulmonary regurgitation after tetralogy of Fallot (ToF) repair, affecting left ventricular (LV) function because of ventricular interaction. The aim of this study was to assess the effect of chronic RV volume loading on LV myocardial mechanics in patients after ToF repair by combining cardiac magnetic resonance imaging with echocardiography.
Seventy-five subjects were studied: 50 patients after ToF repair and 25 age-matched controls. All patients with ToF and controls underwent echocardiography at the time of clinically indicated cardiac magnetic resonance imaging. Myocardial deformation, including LV torsion, was analyzed using speckle-tracking echocardiography.
RV free wall global and segmental longitudinal strain and strain rate were significantly lower in patients with ToF compared with controls (P < .001). All LV longitudinal, strain, and torsion parameters were significantly reduced in patients with ToF (P < .01). Basal rotation was particularly abnormal, with 38% of patients with ToF having reversed basal rotation. In contrast, apical rotation was reduced but not reversed. On multivariate regression analysis, the only significant predictor of counterclockwise basal rotation was RV strain, suggesting that RV function more than dilatation influences abnormal LV torsion.
Patients with ToF have abnormal LV myocardial mechanics, as demonstrated by speckle-tracking echocardiography. The most striking changes were noted in LV torsion, especially related to abnormal LV basal rotation. RV dysfunction seems the most important determinant of abnormal LV rotation. The clinical significance and potential prognostic implications of these observations remain to be determined.
法洛四联症（ToF）修复术后肺反流患者的右心室（RV）容量超负荷会导致RV扩张和功能障碍，由于心室相互作用，还会影响左心室（LV）功能。本研究的目的是通过心脏磁共振成像与超声心动图相结合，评估ToF修复术后患者慢性RV容量负荷对LV心肌力学的影响。
研究了75名受试者：50名ToF修复术后患者和25名年龄匹配的对照组。所有ToF患者和对照组在临床指示进行心脏磁共振成像时均接受了超声心动图检查。使用斑点追踪超声心动图分析心肌变形，包括LV扭转。
与对照组相比，ToF患者的RV游离壁整体和节段性纵向应变及应变率显著降低（P <.001）。ToF患者的所有LV纵向、应变和扭转参数均显著降低（P <.01）。基底旋转尤其异常，38%的ToF患者出现基底旋转逆转。相比之下，心尖旋转减少但未逆转。在多变量回归分析中，逆时针基底旋转的唯一显著预测因素是RV应变，这表明RV功能比扩张更能影响异常的LV扭转。
斑点追踪超声心动图显示，ToF患者存在异常的LV心肌力学。最显著的变化出现在LV扭转中，尤其是与异常的LV基底旋转有关。RV功能障碍似乎是LV异常旋转的最重要决定因素。这些观察结果的临床意义和潜在预后影响仍有待确定。
