心脏磁共振成像技术评价完全性左束支传导阻滞对收缩性心力衰竭患者左心室的影响

Evaluation of left ventricular morphology and function related to complete left bundle branch block with cardiac magnetic resonance in patients with systolic heart failure

目的应用心脏磁共振成像(cardiac magnetic resonance image,CMRI)技术评价完全性左束支传导阻滞(complete left bundle branch block,CLBBB)对收缩性心力衰竭患者左心室形态和功能的影响。方法连续入选因心力衰竭入院、超声心动图测定的左心室射血分数(left ventricular ejection fraction,LVEF)小于50%且合并CLBBB的患者13例作为试验组;选取同时期年龄、性别及LVEF匹配的原发性扩张型心肌病患者19例作为对照组。两组均行CMRI检查,比较CLBBB对心力衰竭患者左心室形态及功能的影响。结果试验组心电图中QRS波时限明显宽于对照组[(147.5±13.1)ms比(108.7±16.9)ms,P<0.001],差异有统计学意义;试验组左心室舒张末容积[(173.8±23.1)ml比(247.9±60.7)ml,P<0.001]、左心室舒张末容积指数[(102.6±19.8)ml/m^2比(147.5±38.3)ml/m^2,P=0.001]、左心室收缩末容积[(123.1±18.7)ml比(188.2±57.1)ml,P<0.001]、左心室收缩末容积指数[(73.1±17.0)ml/m^2比(112.3±36.2)ml/m^2,P=0.001]、左心室舒张末期内径[(56.1±5.0)mm比(66.8±6.5)mm,P<0.001]、右心房面积[(15.7±6.0)cm^2比(20.5±6.2)cm^2,P=0.037]均低于试验组,差异均有统计学意义;试验组平均最大室壁厚度高于对照组[(8.3±1.4)mm比(7.2±1.1)mm,P=0.016],差异有统计学意义。结论 CLBBB可能参与了左心室收缩功能的下降,这种继发因素相关的心力衰竭,左心室扩张不如原发性扩张型心肌病显著,并且左心室壁厚度并不薄。

Objective To evaluate the left ventricular morphology and function related to complete lef t bundle branch block（CLBBB） in patients with systolic heart failure with cardiac magnetic resonance. Methods Thirteen consecutive patients with lef t ventricular ejection f raction（LVEF）〈50% evaluated by echocardiography and CLBBB were included as the study group,and patients with other reasons leading to heart failure were excluded. During At the same period, patients with primary dilated cardiomyopathy were selected as the control group（n=19） whose age, sex and LVEF were matched with the study group. All patients received contrast magnetic resonance imaging examination. Results Lef t ventricular end-diastolic volume（LVEDV） in patients with CLBBB was（173.8±23.1） ml and left ventricular end-systolic volume（LVESV） was（123.1±18.7） ml, while LVEDV in patients without CLBBB was（247.9±60.7） ml and LVESV was（188.2±57.1）ml respectively. All LV measurements/indexes were smaller in patient with CLBBB when compared to the control（all P 〉 0.05）.Right atrium area was also smaller in CLBBB patients（P=0.037）. The maximal wall thickness in the patients with CLBBB [（8.3±1.4） mm] was thicker than that in the patients without CLBBB[（7.2±1.1）mm]（P=0.016）. Conclusions CLBBB may play an important role in the progress of heart failure and LV dilation may not have similar significant contribution with relative thicker ventricular wall.