正常家鸽的宽频带心电图时域值和功率谱

Time domain and power spectrum of wide frequency band electrocardiogram in pigeons

实验用南京新博公司生产的NHE-1000型宽频带心电信息检测分析仪,研究了正常家鸽宽频带心电图(WFB-ECG)的时域值和QRS波群的功率谱。主要结果如下:(1)Ⅱ、Ⅲ、aVF导联,QRS波群均为主波向下,形成rS或 rSr’型,无Q波,与人类相应导联的心电图波形相反;S波的升支均有一较大的切迹(无一例外),Ⅱ导联切迹幅度为 0.413±0.133mV,宽度为9.733±1.291ms;Ⅱ、Ⅲ、aVF导联T波直立,方向均与主波相反门(1例除外)。aVR导联,QRS波群主波向上,形成Rs型,T波倒置,与主波方向相反(无一例外),也与人类aVR导联的波形相反。(2)P波时程与P-R段之比值为0.8,而人的为1.0-1.6,小鼠的为0.4。(3)Ⅱ导联QRS波群的功率谱特点:以低频信号(低于80 HZ)为主,而高频频段的相对能量比小鼠的低,比人的高,其中高频频段100-1000 Hz的相对能量为(10.181±7.443)％,80-300HZ为(15.418±10.579)％。(4)QRS波群的额面心电轴为-118°±10°(-96°～-136°);(5)心电向量环的位置与人类的相反,位于-90°～-180°相限。这些现象的产生原因可能是由于家鸽心室 Purkinje纤维末梢延伸到心外膜下心肌,导致心外膜下心肌先除极化,心内膜下心肌后除极化而产生的。

The wide frequency band ECG (WFB-ECG) was recorded in 33 (anesthetized) normal pi-geons by the microprocessor ECG system (made in Nanjing University) with a wide-frequency response (0- 1000 Hz), a high-speed sweep (up to 1401 mm/s) and a high sensitivity (up to 28 mm/mV). The re-cording methods for limb leads in the pigeon were the same as those in man, except that the needle elec-trodes (made by No. 5 needles) were subcutaneously inserted in the bases of the wings and in the legs. Westudied the features of time domain and power spectrum of pigeons WFB-ECG. It presents P, R, S and Twaves, but no Q wave, basically similar to the results from Aves described by Sturkie. But there are stillmany characters that were not be recorded on the conventional ECG: (1) the main QRS complex is invertedand forms the type of rS or rSr', no Q wave in leads Ⅱ, Ⅲ, aVF, and the S-T segment is absent, which isdifferent from that of humans. The T wave is upright in leads Ⅱ, Ⅲ, and aVF (except one), in agreementwith that of man. But in lead aVR, the main QRS complex is upright and forms the type of Rs, and the Twave is inverted without any exception. There is a large notch on the upstroke of S wave without any excep-tion. The amplitude of the notch is 0. 413±0. 133 mV and the duration is 9. 733±1. 291 ms in lead Ⅱ.(2 ) The ratio of duration of P wave to P-R segment is about 0. 8, lower than that of humans (1. 0 - 1. 6),but higher than that of mice (0. 4). (3 ) The low frequency signals (0 - 80 Hz) are prominent. The rela-tive power content of high frequency range of QRS in lead Ⅱ is: 100 - 1000 Hz: (10. 181±7. 443)%; 80 -300 Hz: (15. 418±10. 579) %. (4) The QRS vector loop in the frontal plane lies between -90°and-180°. The electrical axis of QRS complex averages - 118°±10°(ranges from -96°to -136°). Thereason that position of vector loop and the direction of main wave of QRS in the pigeon are different from hu-man's and rodent's is probably that the Purkinje fibers cross the whole ventricular wall and terminate in thesubepicardium in Aves (including pigeons). After the impulses coming from the sinoatrial node reach theventricular muscles, the subepicardium is depolarized before the endocardium. However in human's and ro-dent's, the Purkinje fibres only reach one-forth to one - second of the whole thickness from the endocardiumto the epicardium, the subendocardium is depolarized before the subepicardium.