Anousheh Ramtin, Sawhney Navinder S, Panutich Michael, Tate Charles, Chen Wei-Chung, Feld Gregory K
Department of Medicine, Division of Cardiology, Clinical Cardiac Electrophysiology Program, UCSD Medical Center, University of California, San Diego, California, USA.
Pacing Clin Electrophysiol. 2010 Apr;33(4):460-8. doi: 10.1111/j.1540-8159.2009.02625.x. Epub 2009 Dec 1.
Successful mitral isthmus (MI) ablation may reduce recurrence of atrial fibrillation (AF) and macro-reentrant atrial tachycardia (AT) after pulmonary vein isolation (PVI) for AF.
To determine if achieving bidirectional MI conduction block (MIB) during circumferential pulmonary vein ablation (CPVA) plus left atrial linear ablation (LALA) affects development of AT.
Sixty consecutive patients with persistent (n = 25) or paroxysmal (n = 35) AF undergoing CPVA plus LALA at the MI and LA roof were evaluated in a prospective, nonrandomized study.
PVI was achieved in all patients. Bidirectional MI block was achieved in 50 of 60 patients (83%). During 18 +/- 5 months follow-up, 12 patients (20%) developed recurrent AF and 15 (25%) developed AT. Patients in whom MIB was not achieved at initial ablation had four times higher risk of developing AT (P = 0.008, 95% confidence interval 1.43-11.48) versus patients with MIB. In 12 patients with AT undergoing repeat ablation, 22 ATs were identified, with reentry involving the MI in nine, the LA roof in six, and the ridge between the LA appendage and left PVs in seven. In patients with MIB at initial ablation, recovery of MI conduction was seen in eight of 13 undergoing repeat ablation.
AT occurring after CPVA plus LALA is often due to incomplete MI ablation, but may also occur at the LA roof, and ridge between the LA appendage and left PVs. Failure to achieve MI block increases the risk of developing AT. Resumption of MI conduction may also be a mechanism for AT recurrence. (PACE 2010; 460-468).
对于心房颤动（AF）患者，成功的二尖瓣峡部（MI）消融可能会降低肺静脉隔离（PVI）术后房颤和大折返性房性心动过速（AT）的复发率。
确定在环肺静脉消融（CPVA）加左心房线性消融（LALA）过程中实现双向MI传导阻滞（MIB）是否会影响AT的发生。
在一项前瞻性、非随机研究中，对60例连续接受CPVA加MI和左心房顶部LALA的持续性房颤（n = 25）或阵发性房颤（n = 35）患者进行了评估。
所有患者均实现了PVI。60例患者中有50例（83%）实现了双向MI阻滞。在18±5个月的随访期间，12例患者（20%）发生了房颤复发，15例（25%）发生了AT。初始消融时未实现MIB的患者发生AT的风险是实现MIB患者的4倍（P = 0.008，95%置信区间1.43 - 11.48）。在12例接受再次消融的AT患者中，共识别出22次AT，其中9次折返涉及MI，6次涉及左心房顶部，7次涉及左心耳与左肺静脉之间的嵴部。在初始消融时实现MIB的患者中，13例接受再次消融的患者中有8例出现了MI传导恢复。
CPVA加LALA术后发生的AT通常是由于MI消融不完全，但也可能发生在左心房顶部以及左心耳与左肺静脉之间的嵴部。未实现MI阻滞会增加发生AT的风险。MI传导恢复也可能是AT复发的一种机制。（《PACE》2010年；460 - 468页）
