双腔起搏器置入患者最佳房室延迟不同设置方法的临床研究

对不同最佳房室延迟(OAVD)设置方法进行比较,探讨OAVD设置的简单、实用的方法。选择36例置入双腔起搏器的患者,设置不同的AVD,于超声心动图下记录左室射血分数(EF)、舒张期二尖瓣返流、A波结束至二尖瓣完全关闭的时间间期(Time1)、最早出现舒张期二尖瓣返流的AVD(临界AVD),并通过同步心电图测定QT间期(QTI)、QT离散度(QTD)及QRS波群时间(QRSI)。将各指标预测的OAVD与OAVD(EF最大时的AVD)进行比较。结果:①心功能正常者心房起搏或心房感知时在AVD为170ms或140~160ms时EF达到最大,且与OAVD时EF相比差异均无显著性;心功能不全者在AVD为130~140ms时EF达到最大,但与OAVD时EF相比差异有显著性。②三种心电图指标预测的OAVD与OAVD比较差异均无显著性,其预测的OAVD在心功能不全患者与OAVD显著相关。③预测OAVD、AVD=200或180ms时预测的OAVD与OAVD比较差异均无显著性。结论:在实际工作中,可通过下述简单方法设置OAVD:OAVD=200ms(或180ms)减去200ms(或180ms)时Time1,以提高随访效率。

Clinical Investigation of Different Methods of Determination of the Optimal Atrioventricular Delay in Patients With Implanted Dual-Chamber Pacemakers

The objectives of this study is to investigate and compare different methods of determination of the optimal atrioventricular delay (OAVD) and try to find a simple and practical method of identifying OAVD.Thirty-six patients implanted with dual-chamber pacemaker and with ventricular-capture were studied. For each patient, different AVDs were set,and ejection fraction (EF),diastolic mitral regurgitation, the interval between the end of the A wave and complete closure of the mitral valve (Time 1) were measured. At the same time,QT interval, QT dispersion and QRS interval were measured synchronously recorded ECG. Different predictions of optimal AVD were achieved through comparison of all the above-mentioned indexes, and were compared with OAVD(the AVD at which EF was the highest).Results:①In patients with normal cardiac function ,EF reached the peak at the AVD 170 ms with atrial-pacing, 140～160 ms with atrial-sensing, and there was no significant differences between the EF at the above mentioned AVD and the EF at the OAVD. In patients with insufficient cardiac function, EF reached the peak at the AVD 130～140 ms with atrial-pacing, but there was significant difference between the EF at any set AVD and the EF at the OAVD.②There was no significant difference between the OAVDs predicted by the ECG indexes and the OAVD and there was a significant positive correlation between them in patients with insufficient cardiac function.③There was no significant difference between the predicted OAVD, the OAVD predicted when the AVD was set at 200 ms or 180 ms and the OAVD and there was a significant positive correlation between each of them. Conclusions:In our practical work, the OAVD can be calculated by using the follow method: OAVD=200 ms(or 180 ms)subduced the time 1 measured at the AVD of 200 ms(or 180 ms).Thus, the follow-up can be simplified and more efficient.