Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
Int J Cardiol. 2011 Feb 17;147(1):88-94. doi: 10.1016/j.ijcard.2009.08.009. Epub 2009 Sep 10.
The evaluation of right ventricular (RV) function is clinically important in pulmonary hypertension (PH) because of prognostic implications. Conventional echocardiography has been used to predict adverse outcomes in chronic PH, but there were certain limitations arising from the complexity of RV anatomy. We used strain rate imaging (SRI) to evaluate RV function in PH patients.
Study population consisted of 50 patients (mean age 46 ± 13 years; 39 females) with chronic PH who underwent echocardiography including SRI within 24h of right heart catheterization. Mean value of peak systolic longitudinal strain obtained from basal and mid RV free wall were calculated. Reduced RV systolic contraction (fractional area change <32%) and cardiac index (CI) <2.0 L/min/m(2) were defined as impaired RV performance.
Pulmonary vascular resistance (PVR) averaged 1195 ± 522 dyn · s · cm(-5). RV strain correlated closely with pulmonary artery systolic pressure (r = 0.53; p < 0.001) and PVR (r = 0.68; p < 0.001). RV strain best correlated with CI (r = -0.70; p < 0.001) among the invasive variables. After adjusting for various parameters that could influence the CI, this correlation remained robust (r = -0.63, p < 0.001). In a multivariate model, RV strain (odds ratio 1.65; 95% confidential interval 1.06-2.57; p = 0.028) was independently associated with impairment of RV performance. A cutoff value of -15.5% discriminated cases of impaired RV performance from those of preserved RV performance with a sensitivity of 100%, specificity of 84% and accuracy of 92%.
RV strain correlates well with hemodynamic variables indicative of disease severity and help identify the cases of impaired RV performance in PH patients.
右心室（RV）功能的评估在肺动脉高压（PH）中具有重要的临床意义，因为它与预后有关。传统的超声心动图已被用于预测慢性 PH 的不良结局，但由于 RV 解剖结构的复杂性，存在一定的局限性。我们使用应变率成像（SRI）来评估 PH 患者的 RV 功能。
研究人群包括 50 名（平均年龄 46±13 岁；39 名女性）接受超声心动图检查的慢性 PH 患者，包括 SRI，在右心导管检查后 24 小时内进行。计算基底和中 RV 游离壁获得的收缩期纵向应变峰值的平均值。RV 收缩功能受损定义为 RV 收缩分数变化率（FAC）<32%和心脏指数（CI）<2.0 L/min/m2。
肺血管阻力（PVR）平均为 1195±522 dyn·s·cm-5。RV 应变与肺动脉收缩压（r=0.53；p<0.001）和 PVR（r=0.68；p<0.001）密切相关。在侵入性变量中，RV 应变与 CI 相关性最好（r=-0.70；p<0.001）。在调整了可能影响 CI 的各种参数后，这种相关性仍然很强（r=-0.63，p<0.001）。在多变量模型中，RV 应变（比值比 1.65；95%置信区间 1.06-2.57；p=0.028）与 RV 功能障碍独立相关。-15.5%的截断值可将 RV 功能障碍与 RV 功能保留的病例区分开来，其敏感性为 100%，特异性为 84%，准确性为 92%。
RV 应变与反映疾病严重程度的血流动力学变量密切相关，有助于识别 PH 患者 RV 功能障碍的病例。
