心房颤动直流电复律前后左心房功能变化的超声心动图研究

目的评价体外直流电复律对心房颤动(房颤)患者复律后左心房大小和容量的影响以及左心房大小与功能的关系。方法随机选择房颤患者68例,按心脏复律的方式分为直流电复律组36例,药物复律组32例,应用超声心动图测定其左房内径和容积,计算左房主动、被动排空容积及左房射血力。分析左房内径和容积变化与左房收缩功能的关系。结果房颤时所有患者的左房扩大,而恢复窦性心律后直流电复律组和药物复律组的左房上下径显著降低(P<0.05或P<0.001)。直流电复律与药物复律组比较,左房最大和最小容积显著增大(P<0.001或P<0.01)。左房机械功能正常患者与25例左房机械功能异常患者比较有较强的左房射血力;左心房机械功能降低的患者左心房内径和容积分别与左心房射血力呈负相关(r=-0.73和-0.78,P<0.001),而且左心房主动排空分数降低,管道容积却增加。结论体外直流电复律后许多患者出现左心房功能降低,心房收缩功能延迟恢复与持续的左房扩大有关;而药物复律患者的左房射血力较强与恢复窦性心律后左房容积明显降低有关。

Changes of left atrial function before and after direct current cardioversion in patients with atrial fibrillation by echocardiography

Objective To evaluate the effect of external direct current shock on left atrial(LA) diamension and volumes after cardioversion for atrial fibrillation(AF) and the relation between LA size and function.Methods The initial study population included 68 patients with AF.According to cardioversion patterns, the patients were divided randomly into cardioversion with direct-current shock(36 patients) and cardioversion with drugs(32 patients). Echocardiographic evaluations included LA size and volume,LA passive and active emptying volumes were calculated,and LA function was measured as LA ejection force (LAEF).The correlation between LA diameters and volumes and LA systolic function was analyzed. Results LA was dilated in all the patients during AF and the superior-infra dimensions of LA decreased after restoration of sinus rhythm in the patients reverted with external direct current shock and the patients reverted with durgs (P<~0.05 or P<~0.001 ). LA maximal and minimal volumes were increased after direct current shock as compared with patients treated with drugs(P<~0.001 or P<~0.01 ).The comparison between patients with a normal mechanical LA function and patients with reduced LA function showed that a higher LA ejection force was associated with a marked reduction in LA size after restoration of sinus rhythm.An inverse relation between LA diameter or LA volumes and LA ejection force was observed in patients with reduced atrial function(r=~-0.73 or r=~-0.78 ,P<~0.001 ).The active emptying fraction was lower,but the conduit volume was increased. Conclusions The atrial function was also decreased after external direct current cardioversion and delay in the recovery of atrial contractility in many patients and this was associated with a persistence of LA dilation.The patients with drugs cardioversion had a higher atrial ejection which was associated with a more marked reduction in LA maximal volume after the restoration of sinus rhythm.