Nakamura Tomofumi, Hachiya Hitoshi, Yagishita Atsuhiko, Tanaka Yasuaki, Higuchi Koji, Kawabata Mihoko, Sasano Tetsuo, Hirao Kenzo
Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
Pacing Clin Electrophysiol. 2016 Apr;39(4):352-60. doi: 10.1111/pace.12814. Epub 2016 Feb 18.
Superior vena cava (SVC) can be a focus of atrial fibrillation (AF). However, distinctive features that identify SVC arrhythmogenicity remain unclear. Sustainability of fibrillation within the SVC might help with identifying SVC arrhythmogenicity. The purpose of this study was to investigate the relationship between the anatomical and electrical profiles of SVC and sustainability of SVC fibrillation induced by proactive electrical stimulation.
Consecutive 36 patients with paroxysmal or persistent AF who underwent repetitive pulmonary vein isolation (PVI) session were included in the study. After successful PVI, periodic rapid electrical stimuli were delivered to the SVC to induce SVC fibrillation. SVC fibrillation was defined as follows: (1) the local fibrillatory electrical activity persisted longer than 3 seconds, (2) the local fibrillatory activity penetrated through the atrium and maintained AF, and (3) the frequency of local activity was higher than that of any other atrial components such as coronary sinus and right atrial appendage.
SVC fibrillation was induced in seven patients. The group with SVC fibrillation had significantly longer SVC sleeve and longer left atrial diameter compared with the group without SVC fibrillation. All patients with SVC fibrillation were free from AF recurrence after SVC isolation.
The SVC sleeve longer than 30 mm had sustainability of SVC fibrillation induced by electrical stimulation. This finding advocates that arrhythmogenic substrate may exist in the SVC with long myocardial sleeve.
上腔静脉（SVC）可能是心房颤动（AF）的一个病灶。然而，识别SVC致心律失常性的独特特征仍不清楚。SVC内颤动的持续性可能有助于识别SVC致心律失常性。本研究的目的是探讨SVC的解剖和电生理特征与主动电刺激诱发的SVC颤动持续性之间的关系。
连续纳入36例接受反复肺静脉隔离（PVI）治疗的阵发性或持续性AF患者。PVI成功后，定期向SVC施加快速电刺激以诱发SVC颤动。SVC颤动的定义如下：（1）局部颤动电活动持续超过3秒；（2）局部颤动活动穿透心房并维持AF；（3）局部活动频率高于任何其他心房成分，如冠状窦和右心耳。
7例患者诱发了SVC颤动。与未发生SVC颤动的组相比，发生SVC颤动的组SVC袖套明显更长，左心房直径更大。所有发生SVC颤动的患者在SVC隔离后均未出现AF复发。
SVC袖套长度超过30 mm具有电刺激诱发的SVC颤动的持续性。这一发现表明，心肌袖长的SVC中可能存在致心律失常基质。
