Differentiation of Atypical Atrioventricular Node Re-Entrant Tachycardia From Orthodromic Reciprocating Tachycardia Using a Septal Accessory Pathway by the Response to Ventricular Pacing
通过对室性起搏的反应，使用间隔旁路区分非典型房室结折返性心动过速和顺向往复性心动过速

The difference between the post-pacing interval (PPI) and tachycardia cycle length (TCL) has been helpful in assessing the proximity of the pacing site to a re-entry circuit (1). Because it is sometimes difficult to differentiate atypical atrioventricular node re-entrant tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT) using a septal accessory pathway, a simple diagnostic maneuver that reliably distinguishes these two types of tachycardia would be valuable. We postulated that the PPI might be helpful in distinguishing AVNRT from ORT using a septal accessory pathway. Because a right ventricular (RV) pacing site is nearer to the re-entry circuit for ORT, the PPI theoretically should more closely approximate the TCL than it would for AVNRT. For the same reason, the stimulus-atrial (S-A) interval during RV entrainment would be expected to more closely approximate the ventriculo-atrial (VA) interval measured during tachycardia. The purpose of this study was to determine whether the response to ventricular pacing during tachycardia is useful for differentiating atypical AVNRT from ORT using a septal accessory pathway.
起搏后间隔 （PPI） 和心动过速周期长度 （TCL） 之间的差异有助于评估起搏部位与折返回路的接近程度 （1）。由于有时很难使用间隔旁路区分非典型房室结折返性心动过速 （AVNRT） 和顺向型折返性心动过速 （ORT），因此可靠区分这两种类型的心动过速的简单诊断作将很有价值。我们假设 PPI 可能有助于使用间隔旁路区分 AVNRT 和 ORT。由于右心室 （RV） 起搏部位更靠近 ORT 的折返回路，因此理论上 PPI 应该比 AVNRT 更接近 TCL。出于同样的原因，预计 RV 夹带期间的刺激-心房 （S-A） 间期更接近心动过速期间测量的心室-心房 （VA） 间期。本研究的目的是确定心动过速期间对心室起搏的反应是否有助于使用间隔旁路区分非典型 AVNRT 和 ORT。

Patient characteristics. This retrospective study included 30 patients with atypical AVNRT and 44 patients with ORT using a septal accessory pathway, who underwent radiofrequency ablation at the University of Michigan Medical Center. The study was approved by the Human Research Committee at the University of Michigan Medical Center. Their mean age was $39\pm 14$$39\pm 14$39+-1439 \pm 14 years; there were 44 men and 30 women. Seven patients had an anteroseptal accessory pathway; 3 patients had a mid-septal accessory pathway; 23 patients had a right posteroseptal accessory pathway; and 11 patients had a left posteroseptal accessory pathway. Twenty-five of 30 patients with AVNRT and 29 of 44 patients with ORT using a septal accessory pathway, had a long RP tachycardia, defined as an $RP/RR$$RP/RR$RP//RRR P / R R ratio $>0.50$$>0.50$> 0.50>0.50. Patients in whom the tachycardia mechanism was not clear, based on conventional criteria ( $\mathrm{n}=4$$\mathrm{n}=4$n=4\mathrm{n}=4 ), or in whom entrainment from the RV could not be performed $(\mathrm{n}=5)$$(\mathrm{n}=5)$(n=5)(\mathrm{n}=5) were excluded. No patient had structural heart disease.
患者特征。这项回顾性研究包括 30 例非典型 AVNRT 患者和 44 例使用间隔旁路的 ORT 患者，他们在密歇根大学医学中心接受了射频消融术。该研究得到了密歇根大学医学中心人类研究委员会的批准。他们的平均年龄是 $39\pm 14$$39\pm 14$39+-1439 \pm 14 几岁;有 44 名男性和 30 名女性。7 例患者有前间隔旁路;3 例患者有中间隔旁路;23 例患者有右侧后间隔旁路;11 例患者有左侧后间隔旁路。30 名 AVNRT 患者中有 25 名，44 名使用间隔心脏旁路的 ORT 患者中有 29 名患有长 RP 心动过速，定义为 $RP/RR$$RP/RR$RP//RRR P / R R 比率 $>0.50$$>0.50$> 0.50>0.50 。根据常规标准 （ $\mathrm{n}=4$$\mathrm{n}=4$n=4\mathrm{n}=4 ） 心动过速机制不明确或无法从 RV 夹 $(\mathrm{n}=5)$$(\mathrm{n}=5)$(n=5)(\mathrm{n}=5) 带的患者被排除在外。没有患者患有结构性心脏病。
Electrophysiologic procedure. Electrophysiologic tests were performed in the fasting state. The patients’ written, informed consent was obtained before sedation. Quadripolar electrode catheters were inserted into a femoral vein and positioned in the high right atrium and $RV$$RV$RVR V apex or septum. A roving quadripolar catheter was moved between the anteroseptal tricuspid valve (His bundle recording) and
电生理检查。在空腹状态下进行电生理检查。镇静前获得患者的书面知情同意。将四极电极导管插入股静脉，并放置在右心房高位和 $RV$$RV$RVR V 心尖或隔膜。在前间隔三尖瓣 （His 束记录） 和

coronary sinus positions. At least four electrocardiographic leads and intracardiac electrograms were recorded and stored on either the EPLab (Quinton Electrophysiology Corp., Seattle, Washington) or EP-WorkMate (EP MedSystems, Inc., Mt. Arlington, New Jersey) recording systems. Bipolar intracardiac electrograms were filtered between 30 and 500 kHz and recorded from the proximal electrode pair at a speed of $100\mathrm{mm}/\mathrm{s}$$100\mathrm{mm}/\mathrm{s}$100mm//s100 \mathrm{~mm} / \mathrm{s}. Bipolar pacing was performed at twice the diastolic threshold from the distal electrode pair by using a Bloom DTU 210 (Bloom Associates, Narberth, Pennsylvania) or an EP MedSystems programmable stimulator. All patients had a single mechanism of paroxysmal supraventricular tachycardia that was successfully eliminated by radiofrequency catheter ablation.
冠状窦位置。至少记录了四条心电图导联和心内电图，并将其存储在 EPLab （Quinton Electrophysiology Corp.， Seattle， Washington） 或 EP-WorkMate （EP MedSystems， Inc.， Mt. Arlington， New Jersey） 记录系统上。在 30 到 500 kHz 之间过滤双极心内电图，并以 的速度从近端电极对记录 $100\mathrm{mm}/\mathrm{s}$$100\mathrm{mm}/\mathrm{s}$100mm//s100 \mathrm{~mm} / \mathrm{s} 。使用 Bloom DTU 210 （Bloom Associates， Narberth， Pennsylvania） 或 EP MedSystems 可编程刺激器，以远端电极对舒张期阈值的两倍进行双极起搏。所有患者都有一个阵发性室上性心动过速的单一机制，通过射频导管消融术成功消除。

Atrial tachycardia was excluded in all patients by the presence of an atrial-ventricular (AV) response after entrainment of the tachycardia from the RV (2). The diagnosis of atypical AVNRT was made when the VA interval in the high right atrium was $\ge 100\mathrm{ms}$$\ge 100\mathrm{ms}$>= 100ms\geq 100 \mathrm{~ms}, the earliest retrograde atrial activation was in the atrial septum and one or more of the following criteria were satisfied: 1) AV block during tachy-
所有患者都因从 RV 夹带心动过速后存在心房-心室 （AV） 反应而被排除 （2）。当右心房的 VA 间期为 $\ge 100\mathrm{ms}$$\ge 100\mathrm{ms}$>= 100ms\geq 100 \mathrm{~ms} 时，最早的逆行心房激活发生在房间隔，并且满足以下一项或多项标准时，诊断为非典型 AVNRT： 1） 快速期间房室传导阻滞
cardia (3); 2) AV dissociation with rapid ventricular pacing at a cycle length between 200 and 250 ms during tachycardia (4); 3) a delta atrial-His bundle (AH) interval $>40\mathrm{ms}$$>40\mathrm{ms}$> 40ms>40 \mathrm{~ms} (5); and 4) a delta His-atrial (HA) interval $>-10\mathrm{ms}$$>-10\mathrm{ms}$> -10ms>-10 \mathrm{~ms} (6).
贲门 （3）;2） 心动过速期间，房室分离伴快速心室起搏，周期长度在 200 至 250 ms 之间 （4）;3） δ 心房-希氏束 （AH） 间期 $>40\mathrm{ms}$$>40\mathrm{ms}$> 40ms>40 \mathrm{~ms} （5）;4） δ 组-心房 （HA） 间期 $>-10\mathrm{ms}$$>-10\mathrm{ms}$> -10ms>-10 \mathrm{~ms} （6）。

The diagnosis of ORT was made when the earliest retrograde activation was in the atrial septum in the absence of the aforementioned criteria, and one or more of the following criteria were satisfied: 1) the tachycardia was reset or terminated by a premature ventricular depolarization that occurred when the His bundle was refractory (3); and 2) the VA interval during tachycardia increased by $\ge 10\mathrm{ms}$$\ge 10\mathrm{ms}$>= 10ms\geq 10 \mathrm{~ms}, with the development of functional bundle branch block (7).
在没有上述标准的情况下，最早的逆行激活发生在房间隔时，诊断为 ORT，并且满足以下一项或多项标准：1） 当 His 束难治时发生的室性过早除极，心动过速被复位或终止 （3）;2） 随着功能性束支传导阻滞的发展，心动过速期间的 VA 间期增加 $\ge 10\mathrm{ms}$$\ge 10\mathrm{ms}$>= 10ms\geq 10 \mathrm{~ms} （7）。

Entrainment of the tachycardia was attempted by pacing the RV at a cycle length 10 to 40 ms shorter than the TCL. Entrainment was confirmed when the atrial cycle length accelerated to the pacing cycle length, without a change in the atrial activation sequence, and the tachycardia resumed after pacing was discontinued. The longest paced cycle length clearly resulting in entrainment was used for analysis. The TCL and interval between the onset of the QRS complex and the high right atrial electrogram (VA interval) were measured in the cycle immediately before pacing. The maximal spontaneous variability in TCL was 30 ms in this study. The S-A interval was measured from the last RV pacing stimulus during entrainment to the last entrained atrial depolarization in the high right atrium. The PPI was measured from the last RV pacing stimulus to the RV electrogram in the first return beat. Examples of these measurements are shown for atypical AVNRT (Fig. 1) and ORT using a septal accessory pathway (Fig. 2).
通过以比 TCL 短 10 至 40 ms 的周期长度起搏来尝试夹带心动过速。当心房周期长度加速到起搏周期长度时，确认夹带，心房激活序列没有变化，起搏停止后心动过速恢复。使用明显导致夹带的最长起搏循环长度进行分析。在起搏前的周期中测量 TCL 和 QRS 波群发作与右心房高位电图之间的间隔 （VA 间期）。在本研究中，TCL 的最大自发变异性为 30 ms。S-A 间期是从夹带期间的最后一次 RV 起搏刺激到右心房高位最后一次夹带的心房除极开始测量的。PPI 是从最后一次 RV 起搏刺激到第一次回跳中的 RV 电图测量的。这些测量的示例显示了非典型 AVNRT（图 1）和使用间隔旁路（图 2）的 ORT。
Statistical analysis. Continuous variables are expressed as the mean value $\pm$$\pm$+-\pm SD. Continuous variables were analyzed using the Student $t$$t$tt test. Nominal variables were compared
统计分析。连续变量表示为平均值 $\pm$$\pm$+-\pm SD。连续变量使用 Student $t$$t$tt 测试进行分析。比较了名义变量

Figure 1. Entrainment of atrioventricular node re-entrant tachycardia (AVNRT) from the right ventricular septum (RVS) at a cycle length of 510 ms. (A) The ventriculo-atrial (VA) interval and tachycardia cycle length (TCL) are measured immediately before entrainment. (B) The stimulus-atrial (S-A) interval is measured from the last pacing stimulus to the last entrained high right atrial (HRA) electrogram, and the post-pacing interval (PPI) is measured from the last pacing stimulus to the return cycle RV electrogram. The S-A-VA interval is 120 ms , and the PPI-TCL is 150 ms . HBd = His bundle distal; $\mathrm{S}=$$\mathrm{S}=$S=\mathrm{S}= stimulus.
图 1.房室结折返性心动过速 （AVNRT） 以 510 ms 的周期长度从右室间隔 （RVS） 夹带。（A） 在夹带前立即测量室室-心房 （VA） 间期和心动过速周期长度 （TCL）。（B） 刺激-心房 （S-A） 间期是从最后一次起搏刺激到最后一次夹带的右心房 （HRA） 电图测量的，起搏后间期 （PPI） 是从最后一次起搏刺激到返回周期 RV 电图测量的。S-A-VA 间隔为 120 毫秒，PPI-TCL 为 150 毫秒。HBd = 他的束远端; $\mathrm{S}=$$\mathrm{S}=$S=\mathrm{S}= 刺激物。

Figure 2. Entrainment of orthodromic reciprocating tachycardia (ORT) using a right posteroseptal bypass tract from the right ventricular apex (RVA) at a cycle length of 440 ms . (A) The ventriculo-atrial (VA) interval and tachycardia cycle length (TCL) are measured immediately before entrainment. (B) The stimulus-atrial (S-A) interval is measured from the last pacing stimulus to the last entrained high right atrial (HRA) electrogram, and the post-pacing interval (PPI) is measured from the last pacing stimulus to the return cycle RV electrogram. The S-A-VA interval is 40 ms , and the PPI-TCL is 80 ms . HBD $=$$=$== His bundle distal; $\mathrm{S}=$$\mathrm{S}=$S=\mathrm{S}= stimulus.
图 2.使用右室后间隔旁路从右心室心尖 （RVA） 以 440 ms 的周期长度夹带顺向性往复性心动过速 （ORT）。（A） 在夹带前立即测量心室-心房 （VA） 间期和心动过速周期长度 （TCL）。（B） 刺激-心房 （S-A） 间期是从最后一次起搏刺激到最后一次夹带的右心房 （HRA） 电图测量的，起搏后间期 （PPI） 是从最后一次起搏刺激到返回周期 RV 电图测量的。S-A-VA 间隔为 40 毫秒，PPI-TCL 为 80 毫秒。HBD $=$$=$== His 束远端; $\mathrm{S}=$$\mathrm{S}=$S=\mathrm{S}= 刺激物。
by Pearson chi-square analysis. A p value $<0.01$$<0.01$< 0.01<0.01 was considered statistically significant after Bonferroni adjustment for multiple comparisons.
通过 Pearson 卡方分析。对于多重比较，在 Bonferroni 调整后，p 值 $<0.01$$<0.01$< 0.01<0.01 被认为具有统计学意义。

Basic measurements. Significant differences in mean values for the VA interval, S-A interval, PPI, S-A-VA interval and PPI-TCL were observed between patients with atypical AVNRT and ORT using a septal accessory pathway (Table 1). No significant difference in the TCL was observed.
基本测量。使用间隔旁路的非典型 AVNRT 和 ORT 患者之间观察到 VA 间期、SA 间期、PPI、S-A-VA 间期和 PPI-TCL 的平均值存在显着差异（表1）。未观察到 TCL 的显著差异。

The S-A-VA interval. A discriminant value for the S-A-VA interval was chosen midway between the lowest value measured in all patients with atypical AVNRT and the highest value measured in all patients with ORT using a septal accessory pathway (Fig. 3). All patients with atypical AVNRT had a S-A-VA interval $>85\mathrm{ms}$$>85\mathrm{ms}$> 85ms>85 \mathrm{~ms} (range 90 to 200), and all patients with ORT using a septal accessory pathway had a S-A-VA interval $<85\mathrm{ms}$$<85\mathrm{ms}$< 85ms<85 \mathrm{~ms} (range 0 to 80).
S-A-VA 区间。选择在所有非典型 AVNRT 患者测得的最低值和所有使用间隔心脏旁路的 ORT 患者测得的最高值之间的中间选择 S-A-VA 间期的判别值（图 3）。所有非典型 AVNRT 患者均具有 S-A-VA 间期 $>85\mathrm{ms}$$>85\mathrm{ms}$> 85ms>85 \mathrm{~ms} （范围 90 至 200），所有使用间隔旁路的 ORT 患者均具有 S-A-VA 间期 $<85\mathrm{ms}$$<85\mathrm{ms}$< 85ms<85 \mathrm{~ms} （范围 0 至 80）。
Table 1. Interval Measurements Used to Distinguish Atypical Atrioventricular Node Re-Entrant Tachycardia From Orthodromic Re-Entrant Tachycardia Using a Septal Accessory Pathway
表 1.使用间隔旁路区分非典型房室结折返性心动过速和顺向折返性心动过速的间隔测量

Data are presented as the mean value $\pm \mathrm{SD}$$\pm \mathrm{SD}$+-SD\pm \mathrm{SD} and range (in parentheses) for interval measurements (all in ms ) used to distinguish atypical atrioventricular node reentrant tachycardia (AVNRT) from orthodromic reentrant tachycardia (ORT) using a septal accessory pathway.
数据表示为间隔测量的平均值 $\pm \mathrm{SD}$$\pm \mathrm{SD}$+-SD\pm \mathrm{SD} 和范围（括号中）（均以毫秒为单位），用于区分非典型房室结折返性心动过速 （AVNRT） 和使用间隔旁路的顺向折返性心动过速 （ORT）。

PPI $=$$=$== post-pacing interval; S-A $=$$=$== stimulus-atrial; $\mathrm{TCL}=$$\mathrm{TCL}=$TCL=\mathrm{TCL}= tachycardia cycle length; $\mathrm{VA}=$$\mathrm{VA}=$VA=\mathrm{VA}= ventriculoatrial.
PPI $=$$=$== 后起搏间隔;S-A $=$$=$== 刺激-心房; $\mathrm{TCL}=$$\mathrm{TCL}=$TCL=\mathrm{TCL}= 心动过速周期长度; $\mathrm{VA}=$$\mathrm{VA}=$VA=\mathrm{VA}= 脑室心房。

The PPI-TCL. Likewise, a discriminant value for the PPI-TCL was chosen midway between the lowest value measured in all patients with atypical AVNRT and the maximal value measured in all patients with ORT using a septal accessory pathway (Fig. 4). All patients with AVNRT had a PPI-TCL $>115\mathrm{ms}$$>115\mathrm{ms}$> 115ms>115 \mathrm{~ms} (range 140 to 260 ), and all patients with ORT using a septal accessory pathway had a PPI-TCL $<115\mathrm{ms}$$<115\mathrm{ms}$< 115ms<115 \mathrm{~ms} (range 0 to 95).
The PPI-TCL.同样，PPI-TCL 的判别值选择在所有非典型 AVNRT 患者中测得的最小值与使用间隔旁路在所有 ORT 患者中测得的最大值之间的中间值（图 4）。所有 AVNRT 患者都有 PPI-TCL $>115\mathrm{ms}$$>115\mathrm{ms}$> 115ms>115 \mathrm{~ms} （范围 140 至 260 ），所有使用房间隔旁路的 ORT 患者都有 PPI-TCL $<115\mathrm{ms}$$<115\mathrm{ms}$< 115ms<115 \mathrm{~ms} （范围 0 至 95）。

Major findings. In this study, the response to RV pacing was found to be useful in distinguishing atypical AVNRT from ORT using a septal accessory pathway. An S-A-VA
主要发现。在这项研究中，发现对 RV 起搏的反应有助于使用间隔旁路区分非典型 AVNRT 和 ORT。一个 S-A-VA

Figure 3. Scatterplot showing the mean value $\pm \mathrm{SD}$$\pm \mathrm{SD}$+-SD\pm \mathrm{SD} of the stimulus-atrial-ventriculo-atrial (S-A-VA) interval (ms) for patients with either orthodromic reciprocating tachycardia (ORT) using a septal accessory pathway or atypical atrioventricular node re-entrant tachycardia (AVNRT). The line drawn at 85 ms represents the discriminant point distinguishing the two forms of long VA tachycardia.
图 3.散点图显示了使用间隔旁路的顺向性折返性心动过速 （ORT） 或非典型房室结折返性心动过速 （AVNRT） 患者的刺激-心房-脑室-心房 （S-A-VA） 间期 （ms） 的平均值 $\pm \mathrm{SD}$$\pm \mathrm{SD}$+-SD\pm \mathrm{SD} 。在 85 ms 处绘制的线代表区分两种形式的长 VA 心动过速的判别点。