Impaired Left Ventricular Mechanics in Pulmonary Arterial Hypertension Identification of a Cohort at High Risk
Impaired Left Ventricular Mechanics in Pulmonary Arterial Hypertension Identification of a Cohort at High Risk
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DOI：
10.1161/circheartfailure.112.000098
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发表时间：
2013-07-01
影响因子：
9.7
通讯作者：
Kane, Garvan C.
中科院分区：
文献类型：
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作者：
Hardegree, Evan L.;Sachdev, Arun;Kane, Garvan C.
背景肺动脉高压（PAH）是以肺血管重构和右心衰竭为特征的疾病。右心室（RV）和左心室（LV）并不单独发挥功能，它们共用一个心包囊和室间隔。我们试图通过斑点追踪应变超声心动图来确定PAH心室相互依赖性及其与LV充盈模式的相关性的临床和预后意义。方法和结果超声心动图在71名新诊断为PAH的成人中进行。为了分别分析LV和RV功能，我们测量了LV和RV的收缩期纵向和周向应变峰值。评估生存期>2年。患者右房扩张（右房容积指数，4419 mL/m2;右室舒张末期面积，34 +/- 9 cm 2），右室功能降低（右室面积变化分数，28 +/- 12%）。斑点追踪超声心动图显示RV游离壁收缩期峰值应变显著降低（-15 +/- 3%）。尽管左心室大小正常，常规左心室收缩功能指标正常（舒张末期内径：42 ± 6 mm;射血分数：65 ± 8%;心脏指数：2.6 ± 0.8 L/min/m2），但患者左心室游离壁收缩应变降低（-15 ± 3%）。左心室游离壁收缩期应变降低与舒张延迟二尖瓣血流多普勒模式相关，P=0.0002。在2年随访期间，19例患者（27%）死亡。LV应变与死亡率增加相关（未校正的风险比，LV游离壁应变每降低5%为2.40，1.22-4.68），当校正年龄、性别、世界卫生组织功能分类和PAH发病机制时，仍具有显著性结论PAH患者压力负荷可导致右心室几何形态改变和功能下降，收缩期应变明显降低。尽管LV射血分数保持不变，但LV收缩期应变也降低，并与早期死亡率相关，突出了PAH中心室相互依赖性的重要性。
Background Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling and right heart failure. The right (RV) and left ventricles (LV) do not function in isolation, sharing a common pericardial sac and interventricular septum. We sought to define the clinical and prognostic significance of ventricular interdependence in PAH and its association with LV filling patterns through speckle-tracking strain echocardiography.Methods and Results Echocardiography was performed in 71 adults with a new diagnosis of PAH. To analyze LV and RV function separately, we measured peak systolic longitudinal and circumferential strain of the LV and RV. Survival was assessed >2 years. Patients had dilated right-sided chambers (right atrial volume index, 4419 mL/m(2); RV end-diastolic area, 34 +/- 9 cm(2)), and reduced RV function (RV fractional area change, 28 +/- 12%). Speckle-tracking echocardiography revealed significant reductions in RV free wall peak systolic strain (-15 +/- 3%). Despite normal LV size and normal conventional measures of LV systolic function (end-diastolic dimension, 42 +/- 6 mm; ejection fraction, 65 +/- 8%; cardiac index, 2.6 +/- 0.8 L/min per m(2)), patients had reduced LV free wall systolic strain (-15 +/- 3%). Decreased LV free wall systolic strain was associated with a delayed relaxation mitral inflow Doppler pattern, P=0.0002. During 2-year follow-up, 19 patients (27%) died. LV strain was associated with increased mortality (unadjusted hazard ratio, 2.40 per 5% decrease in LV free wall strain, 1.22-4.68), which remained significant when adjusted for age, sex, World Health Organization functional class, and PAH pathogenesis (hazard ratio, 3.11, 1.38-7.20).Conclusions The pressure loading in PAH results in geometric alterations and functional decline of the RV, with marked reduction in RV systolic strain. Despite preservation of LV ejection fraction, LV systolic strain was also reduced and associated with early mortality, highlighting the significance of ventricular interdependence in PAH.