Yoshida T, Ikeda H, Hiraki T, Kubara I, Ohga M, Imaizumi T
Department of Internal Medicine III and The Cardiovascular Research Institute, Kurume University School of Medicine, Japan.
J Am Coll Cardiol. 1999 Jan;33(1):55-62. doi: 10.1016/s0735-1097(98)00525-7.
The purpose of this study was to examine whether P wave signal-averaged electrocardiogram (P-SAECG), which detects subtle changes in P wave, detects the concealed accessory atrioventricular pathway (AP).
It is difficult to differentiate atrioventricular reciprocating tachycardia (AVRT) due to the AP from atrioventricular nodal reentrant tachycardia (AVNRT) when the ventricular preexcitation is absent on 12-lead electrocardiograms. By electrophysiological studies, the anterograde conduction in the concealed AP is shown to be blocked near the AP-ventricular interface during sinus rhythm.
P-SAECG during sinus rhythm was performed in 20 normal volunteers (control), 21 patients with AVRT due to the concealed AP, 19 with AVNRT, 22 with paroxysmal atrial fibrillation (PAF), and 7 with automatic atrial tachycardia (AT). The filtered P wave duration (FPD) and AR20 (power spectrum area ratio of 0-20 to 20-100 Hz) were measured and repeated in AVRT, AVNRT and AT groups at one week after catheter ablation.
The anterograde conduction in the concealed left-sided AP was confirmed in all cases by an electrophysiological study. The FPD in AVRT group was more prolonged than that in controls or AVNRT group. Although the FPD was similar between AVRT and PAF groups, AR20 differentiated between the two groups. Ablation of the concealed AP shortened FPD in AVRT group but that of the slow pathway or the atrial focus did not shorten in the AVNRT or AT groups, respectively. The changes in FPD after ablation were correlated with those in the duration of atrial activity by an electrophysiological study (r=0.67).
Our findings suggest that P-SAECG detects the concealed left-sided AP, providing a clinical tool in noninvasively assessing atrial activation patterns.
本研究旨在探讨检测P波细微变化的P波信号平均心电图（P-SAECG）能否检测出隐匿性房室旁路（AP）。
当12导联心电图上无室性预激时，因AP导致的房室折返性心动过速（AVRT）与房室结折返性心动过速（AVNRT）难以鉴别。通过电生理研究发现，隐匿性AP在窦性心律时的前向传导在AP-心室界面附近受阻。
对20名正常志愿者（对照组）、21例因隐匿性AP导致AVRT的患者、19例AVNRT患者、22例阵发性心房颤动（PAF）患者和7例自律性房性心动过速（AT）患者进行窦性心律下的P-SAECG检查。测量滤波后的P波时限（FPD）和AR20（0-20至20-100Hz的功率谱面积比），并在AVRT、AVNRT和AT组导管消融术后1周重复测量。
所有病例经电生理研究均证实隐匿性左侧AP的前向传导。AVRT组的FPD比对照组或AVNRT组更长。虽然AVRT组和PAF组的FPD相似，但AR20可区分这两组。隐匿性AP消融使AVRT组的FPD缩短，但AVNRT组或AT组分别消融慢径路或心房病灶并未缩短FPD。消融后FPD的变化与电生理研究中房性活动持续时间的变化相关（r=0.67）。
我们的研究结果表明，P-SAECG可检测出隐匿性左侧AP，为无创评估心房激动模式提供了一种临床工具。
