Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, New York, USA.
Heart Rhythm. 2011 Aug;8(8):1245-53. doi: 10.1016/j.hrthm.2011.03.011. Epub 2011 Mar 10.
Focal atrial tachycardia (AT) originates from preferential sites, including the tricuspid and mitral annuli. AT arising from the atrioventricular annuli is initiated and terminated with programmed stimulation and is, in general, adenosine and verapamil sensitive. Para-Hisian AT arising from the apex of the triangle of Koch has been considered to be a distinct entity, characterized by unique electrophysiological properties.
We sought to more fully delineate the electrophysiological and electrocardiographic properties of para-Hisian AT in a large series of patients.
The study population consisted of 38 patients (63 ± 15 years; 23 female) with AT from the para-Hisian region. The ATs were focal and originated from the anteroseptal tricuspid annulus, in close proximity to the His bundle recording. Proximity to the His bundle was confirmed by electrogram recordings, fluoroscopy, and centrifugal activation during three-dimensional mapping.
The mean AT cycle length was 421 ± 69 ms. AT was associated with a distinct P-wave morphology that was significantly narrower than the P wave during sinus rhythm. Adenosine (5.0 ± 1.5 mg) terminated AT in 34/35 patients. Intravenous verapamil terminated AT in three of three patients. Catheter ablation was attempted in 30 patients and was successful in 26 (87%).
The para-Hisian region is a source of focal AT, with properties consistent with AT arising circumferentially along the tricuspid and mitral annuli, and should be considered a subset of this broader group of "annular" ATs. The electropharmacologic findings in para-Hisian AT are mechanistically consistent with cyclic AMP-mediated triggered activity.
局灶性房性心动过速（AT）起源于优先部位，包括三尖瓣和二尖瓣环。起源于房室环的 AT 可通过程控刺激启动和终止，通常对腺苷和维拉帕米敏感。从 Koch 三角顶点起源的房室结旁 AT 被认为是一种独特的实体，具有独特的电生理特性。
我们试图在一系列大样本患者中更全面地描述房室结旁 AT 的电生理和心电图特征。
研究人群包括 38 例（63±15 岁；23 例女性）起源于房室结旁区的 AT 患者。AT 为局灶性，起源于三尖瓣环前间隔，紧邻希氏束记录部位。通过电图记录、透视和三维标测时的离心激活来确认其与希氏束的接近程度。
平均 AT 周期长度为 421±69ms。AT 与明显变窄的独特 P 波形态相关，与窦性节律时的 P 波相比明显变窄。腺苷（5.0±1.5mg）终止了 35 例中的 34 例 AT。静脉注射维拉帕米终止了 3 例中的 3 例 AT。30 例患者尝试导管消融，26 例（87%）成功。
房室结旁区是局灶性 AT 的起源部位，其特性与沿三尖瓣和二尖瓣环环形起源的 AT 一致，应被视为更广泛的“环形”AT 亚组。房室结旁 AT 的电生理药理学发现与环磷酸腺苷介导的触发活动机制上一致。
