Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the ...Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the surgery strategy.Methods Mini-maze procedure was defined as follow: Pulmonary vein encircling incision and roof line connecting the two circles lesion,left atrial isthmus lesion,and the right atrial isthmus lesion.There were 517 patients with rheumatic valvular disease and pre-operative atrial fibrillation (AF) undergoing valve surgery plus mini-maze procedure in our hospital in the last 3 years,and 93 patients(18%) had recurrent atrial arrhythmia.Twelve patients(6 males and 6 females,mean age 53.8±7.8 ys) underwent electrophysiological study using 3-D mapping system(10 pts) or conventional mapping method(2 pts).Results The first recurrent time from surgery was 4.4±2.2 months.The mean follow-up time after catheter ablation was(12.0±6.0) months.One patient with sinus bradycardia had recurrent incessant atrial tachycardia (AT),but the AT was terminated by catheter position and never could be induced any more.She underwent a repeat procedure but failed just as the course in the first time, and was treated with DDDR pacemaker plus amiodarone.Six patients had 10 kinds of stable AT,including 5 at right atrial isthmus,2 at roof line,1 related to right atrial incision, 1 at anterior wall of left atrial,and 1 related to left superior pulmonary vene.All the stable AT were eliminated and remained sinus rhythm.Three patients had ATs with variable cycle length and the 3-D mapping suggested macro-reentry AT around mitral annulus.We tried to ablate at routine mitral isthmus and also in coronary sinus,but could not reach bi-directional conduction blocking.The other 2 patients were AF with reconnection at all previous ablation sites.Ablation strategy for AF included lesion at re-conduction sites and complex fractionated atrial electrogram.The patients with AF and mitral isthmus related AT were administrated with DC cardioversion and then took amiodarone.One AT and one AF recurred. Conclusions The recurrent atrial arrhythmia after mini-maze mostly related to reconnection at previous lesion sites and catheter ablation for AT could have a high success rate.It would be very hard to block mitral isthmus after valve replacement,so transmural lesion during surgery procedure is the most important strategy for preventing postoperative atrial arrhythmia.展开更多
详细计算了一台10 MeV的电子直线加速器周围某些关键位置的辐射剂量,并对其进行了连续监测以及累积剂量的测量,测量结果充分说明工作环境是安全的.在迷宫出口位置理论值很好地符合测量值,这充分验证了经验公式的合理性.同时发现迷道内...详细计算了一台10 MeV的电子直线加速器周围某些关键位置的辐射剂量,并对其进行了连续监测以及累积剂量的测量,测量结果充分说明工作环境是安全的.在迷宫出口位置理论值很好地符合测量值,这充分验证了经验公式的合理性.同时发现迷道内剂量衰减趋势与计算模型中使用的距离平方反比规律有所不同,要在迷道长度达到一定值后才能确保经验公式给出的结果是保守的.为了实现对辐射场的连续实时监测,此次测量中使用一种新的数据采集设备Mini-DDL(mini digital data logging).展开更多
辐照型电子直线加速器的应用已经越来越广泛,但是其辐射屏蔽优化一直是需要解决的问题,所以设计出既经济又有效的屏蔽方法是非常有意义的。本文叙述了对一台10 MeV的辐照型电子直线加速器迷道出口的剂量率所进行的经验公式计算和蒙特卡...辐照型电子直线加速器的应用已经越来越广泛,但是其辐射屏蔽优化一直是需要解决的问题,所以设计出既经济又有效的屏蔽方法是非常有意义的。本文叙述了对一台10 MeV的辐照型电子直线加速器迷道出口的剂量率所进行的经验公式计算和蒙特卡罗(Monte Carlo,Fluka)模拟,结合伽马探测器和微型数据采集器Mini-DDL(Mini Digital Data Logging)的连续实时测量结果进行了对比分析。分析结果显示,只要在迷道门处增加一个拐弯,就增加一次反散射,出口处的剂量率会下降一个量级以上,使其不仅低于剂量限值而且合理地达到尽可能低。这个结果是在基本没有增加额外成本的基础上实现的,符合辐射防护ALARA(as low as reasonably achievable)原则,为以后加速器的屏蔽设计提供了很好的参考。展开更多
文摘目的总结Wolf Mini-Maze手术治疗单纯性心房颤动的临床经验,并评价其安全性和疗效。方法自2010年11月起,我科采用AtriCureTM干式双极微创射频消融系统经胸腔镜对2例单纯性心房颤动患者施行了双侧肺静脉隔离及左心耳切除术。结果 2例手术过程顺利,消融术后即刻恢复窦性心律。术后随访3～17个月,维持窦性心律,无卒中及其它并发症发生。结论 Wolf Mini-Maze手术治疗单纯性心房颤动具有微创、简单、安全、高效的特点,值得推广。
文摘Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the surgery strategy.Methods Mini-maze procedure was defined as follow: Pulmonary vein encircling incision and roof line connecting the two circles lesion,left atrial isthmus lesion,and the right atrial isthmus lesion.There were 517 patients with rheumatic valvular disease and pre-operative atrial fibrillation (AF) undergoing valve surgery plus mini-maze procedure in our hospital in the last 3 years,and 93 patients(18%) had recurrent atrial arrhythmia.Twelve patients(6 males and 6 females,mean age 53.8±7.8 ys) underwent electrophysiological study using 3-D mapping system(10 pts) or conventional mapping method(2 pts).Results The first recurrent time from surgery was 4.4±2.2 months.The mean follow-up time after catheter ablation was(12.0±6.0) months.One patient with sinus bradycardia had recurrent incessant atrial tachycardia (AT),but the AT was terminated by catheter position and never could be induced any more.She underwent a repeat procedure but failed just as the course in the first time, and was treated with DDDR pacemaker plus amiodarone.Six patients had 10 kinds of stable AT,including 5 at right atrial isthmus,2 at roof line,1 related to right atrial incision, 1 at anterior wall of left atrial,and 1 related to left superior pulmonary vene.All the stable AT were eliminated and remained sinus rhythm.Three patients had ATs with variable cycle length and the 3-D mapping suggested macro-reentry AT around mitral annulus.We tried to ablate at routine mitral isthmus and also in coronary sinus,but could not reach bi-directional conduction blocking.The other 2 patients were AF with reconnection at all previous ablation sites.Ablation strategy for AF included lesion at re-conduction sites and complex fractionated atrial electrogram.The patients with AF and mitral isthmus related AT were administrated with DC cardioversion and then took amiodarone.One AT and one AF recurred. Conclusions The recurrent atrial arrhythmia after mini-maze mostly related to reconnection at previous lesion sites and catheter ablation for AT could have a high success rate.It would be very hard to block mitral isthmus after valve replacement,so transmural lesion during surgery procedure is the most important strategy for preventing postoperative atrial arrhythmia.
文摘详细计算了一台10 MeV的电子直线加速器周围某些关键位置的辐射剂量,并对其进行了连续监测以及累积剂量的测量,测量结果充分说明工作环境是安全的.在迷宫出口位置理论值很好地符合测量值,这充分验证了经验公式的合理性.同时发现迷道内剂量衰减趋势与计算模型中使用的距离平方反比规律有所不同,要在迷道长度达到一定值后才能确保经验公式给出的结果是保守的.为了实现对辐射场的连续实时监测,此次测量中使用一种新的数据采集设备Mini-DDL(mini digital data logging).
文摘辐照型电子直线加速器的应用已经越来越广泛,但是其辐射屏蔽优化一直是需要解决的问题,所以设计出既经济又有效的屏蔽方法是非常有意义的。本文叙述了对一台10 MeV的辐照型电子直线加速器迷道出口的剂量率所进行的经验公式计算和蒙特卡罗(Monte Carlo,Fluka)模拟,结合伽马探测器和微型数据采集器Mini-DDL(Mini Digital Data Logging)的连续实时测量结果进行了对比分析。分析结果显示,只要在迷道门处增加一个拐弯,就增加一次反散射,出口处的剂量率会下降一个量级以上,使其不仅低于剂量限值而且合理地达到尽可能低。这个结果是在基本没有增加额外成本的基础上实现的,符合辐射防护ALARA(as low as reasonably achievable)原则,为以后加速器的屏蔽设计提供了很好的参考。
