Yamada T, Fukunami M, Kumagai K, Abe Y, Kim J, Sanada S, Hori M, Kamada T, Hoki N
Division of Cardiology, Osaka Prefectural Hospital, Japan.
J Am Coll Cardiol. 1996 Sep;28(3):738-44. doi: 10.1016/0735-1097(96)00197-0.
This study sought to determine whether patients with sick sinus syndrome could be detected by analyzing the initial portion of the signal-averaged P wave corresponding to the electrical activity of the perinodal atrial myocardial cells.
In sick sinus syndrome, pathophysiologic abnormalities have been shown not only in the sinus node, but also in the atrial muscle, especially the perinodal portion.
The study included 41 patients with sick sinus syndrome and 140 age-matched control subjects. Eighteen of 41 patients with sick sinus syndrome had paroxysmal atrial fibrillation. Signal-averaged P wave electrocardiograms (ECGs) were recorded through a bandpass filter of 40 to 300 Hz with a P wave-triggering technique. Signals of the orthogonal bipolar leads were combined into a spatial magnitude. The root mean square voltage for the initial 30 ms (EP30) and the duration of initial low amplitude signals < 4 microV (ED4) of the filtered P wave were measured. The root mean square voltage for the last 20 ms (LP20) and the duration of the filtered P wave were also measured.
EP30 was significantly lower and ED4 was significantly longer in patients with sick sinus syndrome than in the control subjects (EP30 [mean +/- SD]: 2.18 +/- 0.90 vs. 3.94 +/- 1.45 microV, p < 0.0001; ED4: 31.7 +/- 14.5 vs. 14.0 +/- 7.4 ms, p < 0.0001), although there was no significant difference in LP20 between patients with sick sinus syndrome without paroxysmal atrial fibrillation and the control subjects. The duration of the filtered P wave was significantly but minimally longer in patients with sick sinus syndrome than in the control subjects (139.8 +/- 18.8 vs. 127.3 +/- 13.6 ms, p < 0.0001). The criteria of EP30 < 3.0 microV and ED4 > 22 ms as atrial early potential gave a sensitivity of 76%, a specificity of 91%, a positive predictive value of 74% and a negative predictive value of 93% for identification of patients with sick sinus syndrome.
These results suggest that the long, low amplitude signals early in the filtered P wave on the signal-averaged ECGs are characteristic of sick sinus syndrome. Thus, the atrial early potential could be a useful marker to identify patients with sick sinus syndrome.
本研究旨在确定通过分析与结周心房肌细胞电活动相对应的信号平均P波的起始部分，能否检测出病态窦房结综合征患者。
在病态窦房结综合征中，病理生理异常不仅出现在窦房结，也出现在心房肌，尤其是结周部分。
本研究纳入41例病态窦房结综合征患者和140例年龄匹配的对照者。41例病态窦房结综合征患者中有18例发生阵发性心房颤动。采用P波触发技术，通过40至300Hz的带通滤波器记录信号平均P波心电图。将正交双极导联的信号合并为空间幅度。测量滤波后P波初始30ms的均方根电压（EP30）和初始低幅度信号（<4μV）的持续时间（ED4）。还测量了最后20ms的均方根电压（LP20）和滤波后P波的持续时间。
病态窦房结综合征患者的EP30显著低于对照者，ED4显著长于对照者（EP30[均值±标准差]：2.18±0.90μV对3.94±1.45μV，p<0.0001；ED4：31.7±14.5ms对14.0±7.4ms，p<0.0001），尽管无阵发性心房颤动的病态窦房结综合征患者与对照者之间的LP20无显著差异。病态窦房结综合征患者滤波后P波的持续时间显著但轻微长于对照者（139.8±18.8ms对127.3±13.6ms，p<0.0001）。以EP30<3.0μV和ED4>22ms作为心房早期电位的标准，对病态窦房结综合征患者的识别敏感性为76%，特异性为91%，阳性预测值为74%，阴性预测值为93%。
这些结果表明，信号平均心电图上滤波后P波早期的长时、低幅度信号是病态窦房结综合征的特征。因此，心房早期电位可能是识别病态窦房结综合征患者的有用标志物。
