Objective To assess the value of QRS characteristics in evaluating cardiac function and ventricular mechanical activity in patients with dilated cardiomyopathy (DCM ).Methods Eighty DCM patients were divided into three groups according to QRS characteristics : normal QRS duration(<120 ms) (group N ,n= 30),wide QRS duration (>120 ms) with right bundle branch block (RBBB) or RBBB - like (group R, n=18),and wide QRS duration with left bundle branch block (LBBB ) or LBBB-like (group L , n=32) .These patients were also divided into four groups according to QRS duration :QRS duration<120 ms(n=30),QRS duration= 120-139 ms (n=18),QRS duration= 140-159 ms (n=22),and QRS duration≥160 ms (n= 10 ) .Left ventricu-lar end diastolic diameter (LVEDD ),left ventricular ejection fraction (LVEF), mitral regurgitant area (M RA ), aortic pre-ejection interval (APEI) and pulmonary pre-ejection interval (PPEI ) were measured by Doppler echocardiography . Interventricular delay (IVD ) was defined as the difference between APEI and PPEI and IVD>40 ms was regarded as interventricular dyssynchro-ny .The intervals from the onset of the QRS complex to the onset of myocardial contraction of the 6 left ventricular segments were determined by tissue Doppler imaging . Interventricular delay (INVD) was defined as the difference between the longest and the shortest interval and INVD> 38 ms was regarded as intraventricular dyssynchrony .Results Compared with group N ,LVEDD significantly increased in group L (P<0 .05) .No obvious differences in LVEDD were found between group R and group N ,as well as between group R and group L (P>0 .05) . The M RA and incidence of interventricular and /or intraventricular dyssynchrony increased but LVEF decreased sequentially from group N to group L ,and the changes became remarkable gradually with the increase in QRS duration (all P<0 .05 ) .Compared with patients with QRS duration≥120 ms,the incidence of interventricular and/or intraventricular dyssynchrony significantly decreased in patients with QRS duration<120 ms (10% vs 64% , P<0 .001) .Conclusion QRS morphological characteristics are valuable in evaluating cardiac function and ventricular mechanical activity in pa -tients with DCM :the wider the QRS duration ,the lower the left ventricular contractility ,and the higher the incidence of interventricular and/or intraventricular dyssynchrony , especially in patients with LBBB.%目的 探讨QRS图形特征对扩张型心肌病(DCM)患者心功能及心室机械活动的评估价值.方法 选取DCM患者80例,按QRS图形特征分为3 组:QRS时限正常组(＜120 ms,N组)30例;宽QRS(≥120 ms)并呈右束支或类右束支阻滞组(R组)18例;宽QRS(≥120 ms)并呈左束支或类左束支阻滞组(L组)32例.根据QRS时限将80例患者分为4组:QRS＜120 ms组30例、120~139 ms组18例、140~159 ms组22例,≥160 ms组10例.以多普勒超声诊断仪测量左室舒张末径(LVEDD)、左室射血分数(LVEF)、二尖瓣反流面积(MRA)、主动脉射血前间期 (APEI)、肺动脉射血前间期(PPEI).以APEI与PPEI的差值为室间延迟(IVD),IVD>40 ms定义为室间不同步.采用组织多普勒技术测量QRS波群起点到左心室6个节段心肌收缩开始的时间,取其中最长与最短的时间差值作为室内延迟(INVD),INVD>38 ms定义为室内不同步.结果 与N组相比,L组LVEDD增大(P＜0.05),R组与N、L组比较差异无统计学意义(P＞0.05).MRA、室间和(或)室内不同步的总发生率均按N、R、L组顺序依次增加(均P<0.05),而LVEF依次减少(均P<0.05),并随着QRS时限的增加这种变化愈显著(均P＜0.05).QRS时限＜120 ms与≥120 ms的患者,室间和(或)室内不同步的总发生率差异有统计学意义[10%(3/30)比64%(32/50),P＜0.001].结论 QRS图形特征对DCM患者心功能与心室的机械活动有一定的评估价值:QRS时限越宽,尤其是呈左束支或类左束支阻滞图形时,左室收缩功能越差,室间和(或)室内机械不同步发生率越高.
展开▼
