Fröhlig G, Schwerdt H, Schieffer H, Bette L
Medizinische Universitätsklinik, Innere Medizin III, Homburg, West Germany.
J Am Coll Cardiol. 1988 Apr;11(4):806-13. doi: 10.1016/0735-1097(88)90215-x.
To give some explanation for atrial malsensing in dual chamber pacing that occurs only during exercise, atrial electrograms from 33 patients were telemetrically recorded and analyzed in both the time and frequency domains. During exercise, an overall decrease from 6.4 +/- 1.9 to 5.6 +/- 1.9 mV (-11%) in the atrial signal amplitude was noted. Despite considerable variability among patients, marked changes occurred in 15 patients whose signals diminished by 11 to 49%. Slew rates showed a similar decrease from 1.35 +/- 0.45 to 1.18 +/- 0.45 V/s (-10.8%), with individual changes of as much as -51%. Signal attenuation in the time domain correlated well with frequency data, exhibiting a highly significant reduction of signal energy between 25 and 105 Hz. However, spectral distribution changed from rest to exercise, with a relative increase of signal energy in the range between 5 and 25 Hz and a decrease at higher frequencies. Individual changes differed widely when low (15 to 65 Hz) and high (65 to 115 Hz) frequencies were compared, but in a group of 11 patients signal attenuation in the high frequency band was more pronounced (-45%) than in the low frequency band (-23%). The clinical impact of the change in frequency distribution during ergometry was visualized by computer simulation of two different (low and high bandpass) filters. Although in individual patients, both characteristics may be favorable with respect to atrial sensing, it was observed in 11 patients that high pass filtering attenuates signal amplitudes by 10 to 24% in excess of the variation without filtering.(ABSTRACT TRUNCATED AT 250 WORDS)
为解释仅在运动期间发生的双腔起搏时心房感知不良的情况，对33例患者的心房电图进行遥测记录，并在时域和频域进行分析。运动期间，心房信号幅度总体从6.4±1.9 mV降至5.6±1.9 mV（-11%）。尽管患者之间存在很大差异，但15例患者出现了显著变化，其信号降低了11%至49%。上升速率也有类似下降，从1.35±0.45 V/s降至1.18±0.45 V/s（-10.8%），个别变化高达-51%。时域中的信号衰减与频率数据相关性良好，在25至105 Hz之间信号能量显著降低。然而，频谱分布从静息到运动发生了变化，5至25 Hz范围内的信号能量相对增加，高频处降低。比较低频率（15至65 Hz）和高频率（65至115 Hz）时，个体变化差异很大，但在一组11例患者中，高频带的信号衰减（-45%）比低频带（-23%）更明显。通过对两种不同（低通和高通）滤波器的计算机模拟，直观显示了运动试验期间频率分布变化的临床影响。尽管在个别患者中，这两种特性对心房感知可能都是有利的，但在11例患者中观察到，高通滤波使信号幅度衰减10%至24%，超过未滤波时的变化。（摘要截短于250字）
