Hôpital Cardiologique du Haut Lévêque, CHU Bordeaux, Pessac, France.
Heart Rhythm. 2013 Dec;10(12):1785-91. doi: 10.1016/j.hrthm.2013.09.068. Epub 2013 Sep 25.
Distinguishing retrograde nodal conduction from extranodal conduction using an accessory pathway (AP) can sometimes be challenging.
To distinguish nodal from extranodal ventriculoatrial (VA) conduction regardless of AP location by proposing a simple method. This method is based on the principle that moving the pacing site progressively from the basal region toward the entrance of the His-Purkinje system should shorten VA time for nodal but not for AP conduction.
Sixty-seven patients with supraventricular tachycardia were prospectively recruited. Quadripolar catheters were placed at the right ventricular (RV) apex, right atrium, and His and coronary sinus. The RV septum was sequentially paced at 4 sites: (1) basal, (2) high midventricle, (3) low midventricle, and (4) apex at a cycle length 100 ms shorter than the resting cycle length. The stimulus-to-atrial (SA) interval was measured by using the proximal coronary sinus atrial electrogram.
Group 1 (n = 33) had nodal VA conduction; all patients had typical atrioventricular nodal reentrant tachycardia. Group 2 (n = 34) had extranodal VA conduction via an AP: 19 left-sided, 6 right-sided, and 9 posteroseptal. In group 1, the SA interval decreased significantly as pacing site moved closer toward the apex (site 1: 166 ± 35 ms, site 2: 153 ± 32 ms, site 3: 149 ± 32 ms, site 4: 154 ± 33 ms, P < .001, respectively, at sites 2-4 compared with site 1). In contrast, in group 2, the SA interval increased significantly toward the apex (site 1: 149 ± 45 ms, site 2: 158 ± 43 ms, site 3: 161 ± 43 ms, and site 4: 163 ± 40 ms, P < .001, respectively, at sites 2-4 compared with site 1). The SA interval at the high midventricular site (site 2) - SA interval at the base (site 1) ≤ 0 ms for nodal and > 0 ms for extranodal conduction had optimal sensitivity and specificity (nodal: selectivity = 97.0% and specificity = 85.3%; extranodal: selectivity = 85.3% and specificity = 97.0%).
Differential sequential pacing of the RV septum reliably distinguishes retrograde atrioventricular nodal conduction from AP conduction.
使用附加径路（AP）区分逆行性结内传导与结外传导有时具有挑战性。
提出一种简单的方法，无论 AP 位置如何，都可以区分结性与结外性房室（VA）传导。该方法基于这样的原理，即逐渐将起搏部位从基底部向希氏-浦肯野系统的入口移动，应该会缩短结性传导的 VA 时间，但不会缩短 AP 传导的 VA 时间。
前瞻性招募了 67 例患有室上性心动过速的患者。将四极导管放置在右心室（RV）心尖、右心房和希氏束及冠状窦。以比静息心动周期短 100ms 的周长依次起搏 RV 间隔 4 个部位：（1）基底，（2）高中间隔，（3）低中间隔，（4）心尖。使用近端冠状窦房内电图测量刺激-房（SA）间期。
第 1 组（n=33）有结性 VA 传导；所有患者均有典型的房室结折返性心动过速。第 2 组（n=34）通过 AP 有结外 VA 传导：19 例左侧，6 例右侧，9 例后间隔。在第 1 组中，随着起搏部位向心尖移动，SA 间期显著缩短（部位 1：166±35ms，部位 2：153±32ms，部位 3：149±32ms，部位 4：154±33ms，部位 2-4 与部位 1 相比，P<.001）。相比之下，在第 2 组中，SA 间期随着向心尖的移动而显著增加（部位 1：149±45ms，部位 2：158±43ms，部位 3：161±43ms，部位 4：163±40ms，部位 2-4 与部位 1 相比，P<.001）。RV 间隔高位中间部位（部位 2）-SA 间隔基底（部位 1）≤0ms 用于结性传导，>0ms 用于结外传导具有最佳的敏感性和特异性（结性：选择性=97.0%和特异性=85.3%；结外性：选择性=85.3%和特异性=97.0%）。
RV 间隔的差速顺序起搏可靠地区分逆行性房室结内传导与 AP 传导。
