Quintos R F, Barakat T, Mecca A, Olshansky B
Loyola University Medical Center, Maywood, Illinois, USA.
J Interv Card Electrophysiol. 2001 Mar;5(1):109-18. doi: 10.1023/a:1009826412380.
The purpose of this study is to determine the reliability of activation sequence mapping in assessing the presence of bidirectional conduction block (BCB) in typical atrial flutter (AFL) ablation.
Radiofrequency ablation (RFA) can cure typical AFL by creating BCB across the right atrial isthmus. Effective conduction block across this region can prevent AFL recurrence, but accurate assessment of isthmus conduction may be flawed.
BCB was measured before and after RFA by pacing at multiple rates on both sides of the isthmus during sinus rhythm. Pacing was performed from a low lateral tricuspid annulus site (proximal to the isthmus) and a coronary sinus Os site (distal to the isthmus), while recording simultaneously from 8-10 right atrial sites bordering the isthmus (4-5 free wall sites; 4-5 septal sites) as well as from an isthmus site. After ablation reinduction of atrial flutter was attempted from both sides of the block with rapid atrial pacing after BCB was established in all patients. In some patients lines of conduction block were evident at the isthmus (using the ablation catheter to map).
Of 65 patients undergoing RFA of AFL, 59 had typical AFL. In all 59 patients, BCB was demonstrated at all pacing cycle lengths 30 min after RFA applications. In 6 of these 59, AFL was inducible with atrial pacing despite apparent BCB. Further RFA resulted in non inducibility in all 6 patients. In the remaining 53/59 patients, BCB was associated with noninducibility at 30 min. A total of 8 recurrences were seen during a mean 19.3 +/- 8.3 (SD) month follow-up.
Apparent BCB as determined by activation sequence mapping outside of the isthmus is an excellent marker, but, as measured, may be a misleading method of assessing the presence or absence of conduction through the isthmus. It is necessary to attempt reinduction of AFL after apparent success. Elimination of typical AFL does not preclude other AFLs.
本研究旨在确定激动顺序标测在评估典型心房扑动（AFL）消融中双向传导阻滞（BCB）存在情况时的可靠性。
射频消融（RFA）可通过在右心房峡部形成BCB来治愈典型AFL。该区域有效的传导阻滞可防止AFL复发，但峡部传导的准确评估可能存在缺陷。
在窦性心律时，通过在峡部两侧以多种频率起搏，在RFA前后测量BCB。起搏从低位三尖瓣环外侧部位（峡部近端）和冠状窦口部位（峡部远端）进行，同时从与峡部相邻的8 - 10个右心房部位（4 - 5个游离壁部位；4 - 5个间隔部位）以及一个峡部部位进行记录。在所有患者建立BCB后，用快速心房起搏从阻滞两侧尝试诱发心房扑动。在一些患者中，峡部可见传导阻滞线（使用消融导管进行标测）。
65例行AFL射频消融的患者中，59例为典型AFL。在所有59例患者中，RFA应用30分钟后，在所有起搏周期长度下均显示BCB。在这59例中的6例中，尽管有明显的BCB，但心房起搏仍可诱发AFL。进一步的RFA使所有6例患者均不能诱发。在其余53/59例患者中，30分钟时BCB与不能诱发相关。在平均19.3±8.3（标准差）个月的随访期间共观察到8次复发。
通过峡部外激动顺序标测确定的明显BCB是一个很好的标志，但如所测量的那样，可能是评估峡部是否存在传导的一种误导性方法。在表面成功后有必要尝试诱发AFL。消除典型AFL并不排除其他类型的AFL。
