经食管信号叠加记录窦房结电图的实验与临床研究

Experimental and Clinical Study of Sinus Node Electrogram by Transesophageal Signal Averaging Technique

目的：探讨无创性经食管信号叠加直接记录窦房结电位(SNP)的技术。方法：对8只犬进行了系统实验研究，并对256例食管电生理检查窦房结传导时间(SACT)和窦房结恢复时间(SNRT)均在正常范围的患者，其中男142例、女114例，年龄10～74(44.2±12.4)岁进行检测。采用自制三导心电微电位检测仪将食管导联的信号放大(增益达到100_μV/cm)、滤波(0.1～50Hz)，16位模/数(A/D)转换，系统采样频率2kHz，对信号进行叠加，189例(74%)记录到食管 SNP。结果：所测信号叠加食管 SNP 为 P 波前的低幅、低频波，可见有两种形态：园顶型(60%)和上斜型(40%)。所测窦房传导时间为(83.3±26.7)ms，分布范围为(23～118)rm；波幅为3.5～27.7μV；dv/dt为0.43～1.93mV/s。结论：我们认为在适当的滤波、高增益和抗基线漂移技术条件下，利用经食管信号叠加技术，大多数窦房结功能正常的患者可直接记录到食管 SNP。

Objective To explore a noninvasive transesophageal signal averaging technique for direct recording of sinus node po-tential (SNP).Methods In order to study sinus nodes potentials by recordings of the esophageal leads,8 dogs were used in a series of ex-periments.The signals from lead I,surface averaged lead and esophagus averaged lead were amplified (up to 100μV/cm),filtered(O.1～50Hz),AD converted to 16 bit accuracy at a sampling rate of 2 kHz and averaged by using the three channel low-noise amplifier.SNPswere recorded from 189 of 256 patients with normal sino-atrial conduction time and sinus node recovery time (74%),comparable to that(46%) recorded by conventional transesophageal technique.Of them,142 were male and 114 were female ranging in age from 10 to 74years (mean (44.2±12.4) years).Results The signal averaged esophageal SNPs were deflections of low-amplitude and low-frequencypreceding the P wave.Twe morphologies,including the domed wave (114 of 189 patients,60%) and the smooth upstroke slope (75 of 189patients,40%),could be seen.The directly recorded sinoatrial conduction time was (83.3±26.7) msec,ranged from 23 to 118 msec,amplitude was 3.5～27.7μV and dv/dt was 0.43～1.93mV/sec.Conclusion We think that signal averaged sinus node electrogam couldbe recorded in sinus rhythm in most patients with normal sinus node function and proper filter settings,high amplification and anti-drifttechnique are important in recording signal averaged esophageal sinus node electogram.