Radiofrequency catheter ablation (RFCA) for pulmonary artery ventricular arrhythmia (PAVA) can be difficult because of the occasional existence of PAVA with preferential conduction.

This study described the characteristics of PAVA that demonstrate preferential conduction.

We analyzed electrocardiographic and electrophysiological data from 8 patients found to have PAVAs with preferential conduction out of 183 patients (4.4%) with right ventricular outflow tract (RVOT) arrhythmias who underwent RFCA at our hospitals. The PAVA with preferential conduction were classified into two types. In type 1 PAVA, successful ablation sites (success-sites) exhibited discrete prepotentials with an isoelectric line, in which the activation time (AT) was ≥ 50 milliseconds. In type 2 PAVA, excellent pace mapping was achieved at two sites separated by ≥ 20 mm: one in the RVOT free wall and the other at the success-site in the pulmonary artery. Type 1 and 2 PAVA features were considered signs of a short and long preferential conduction pathway, respectively.

There were four patients each with type 1 and 2 PAVA. Type 1 PAVA was distinguished by the isoelectric line at success-sites with the mean AT of 78 ± 25.1 milliseconds. In type 2 PAVAs, although the AT at RVOT sites was very short (18.5 ± 10.1 milliseconds), the AT at success-sites was longer than that at the RVOT by 42.3 ± 36.2 milliseconds. Type 2 PAVAs displayed distinct electrocardiogram (ECG) features (R wave in lead I, RR′ in inferior leads, and transitional zone in V4) not found in typical PAVA ECGs.

PAVA with preferential conduction can manifest in distinct ways on the ECG and intracardiac mapping. Knowledge of these features may facilitate successful RFCA of such PAVA cases.

射频导管消融 (RFCA) 治疗肺动脉室性心律失常 (PAVA) 可能很困难，因为偶尔存在优先传导的 PAVA。

该研究描述了显示优先传导的 PAVA 的特征。

我们分析了在我们医院接受 RFCA 的 183 名右心室流出道 (RVOT) 心律失常患者 (4.4%) 中 8 名发现 PAVA 优先传导的患者的心电图和电生理数据。具有优先传导的PAVA分为两种类型。在 1 型 PAVA 中，成功消融位点（成功位点）表现出具有等电位线的离散预电位，其中激活时间 (AT) ≥ 50 毫秒。在 2 型 PAVA 中，在相距 ≥ 20 mm 的两个部位实现了出色的起搏映射：一个在 RVOT 游离壁，另一个在肺动脉的成功部位。1 型和 2 型 PAVA 特征分别被认为是短和长优先传导通路的标志。

有四名患者分别患有 1 型和 2 型 PAVA。1 型 PAVA 通过成功位点的等电位线来区分，平均 AT 为 78 ± 25.1 毫秒。在 2 型 PAVA 中，虽然 RVOT 站点的 AT 很短（18.5 ± 10.1 毫秒），但成功站点的 AT 比 RVOT 的 AT 长 42.3 ± 36.2 毫秒。2 型 PAVA 显示出典型 PAVA ECG 中没有的明显心电图 (ECG) 特征（I 导联中的 R 波，下导联中的 RR' 和 V4 中的过渡区）。

具有优先传导的 PAVA 可以在 ECG 和心内标测上以不同的方式表现出来。了解这些特征可以促进此类 PAVA 案例的成功 RFCA。