Moriya K, Kato K, Matsumura M, Dzialowski E, Burggren W W, Tazawa H
Department of Electrical and Electronic Engineering, Muroran Institute of Technology, 050-8585, Muroran, Japan.
Comp Biochem Physiol A Mol Integr Physiol. 2002 Apr;131(4):787-95. doi: 10.1016/s1095-6433(02)00016-8.
Six emu hatchlings were non-invasively measured for electrocardiogram (ECG) from their chest wall using flexible electrodes, and the instantaneous heart rate (IHR) was determined from ECG throughout the first week of post-hatching life. Although the baseline heart rate (HR) was low, approximately 100-200 beats per min (bpm), compared with chick hatchlings, the IHR fluctuated markedly. The fluctuation of IHR comprised HR variability and irregularities that were designated as types I, II and III in chick hatchlings and additional large accelerations distinctive of emu hatchlings. Type I was HR oscillation with a mean frequency of 0.37 Hz (range 0.2-0.7 Hz), i.e. respiratory sinus arrhythmia (RSA). From RSA, breathing frequency in emu hatchlings was estimated to be approximately half of that in chickens. Type II HR oscillation was also found in the emu; the frequency ranged from approximately 0.04 to 0.1 with a mean of 0.06 Hz, and the magnitude tended to be large compared with that of chickens. In addition to type III HRI, which was designated in chickens, large, irregular HR accelerations were characteristic of emu hatchlings. From IHR data, developmental patterns of mean heart rate (MHR) were constructed and plotted on a single graph to inspect the diurnal rhythm of MHR by visual inspection and power spectrum analysis. A circadian rhythm was not clear in the emu hatchlings, in contrast to chick hatchlings, which showed a dominant diurnal rhythm.
使用柔性电极对6只鸸鹋雏鸟进行了胸壁心电图（ECG）的无创测量，并在孵化后第一周内通过ECG测定了瞬时心率（IHR）。尽管与雏鸡相比，基线心率（HR）较低，约为每分钟100 - 200次心跳（bpm），但IHR波动明显。IHR的波动包括HR变异性和不规则性，在雏鸡中被指定为I、II和III型，以及鸸鹋雏鸟特有的额外大幅加速。I型是平均频率为0.37 Hz（范围0.2 - 0.7 Hz）的HR振荡，即呼吸性窦性心律失常（RSA）。根据RSA，估计鸸鹋雏鸟的呼吸频率约为鸡的一半。在鸸鹋中也发现了II型HR振荡；频率范围约为0.04至0.1，平均为0.06 Hz，与鸡相比，其幅度往往较大。除了在鸡中指定的III型HRI外，大幅、不规则的HR加速是鸸鹋雏鸟的特征。根据IHR数据，构建了平均心率（MHR）的发育模式，并绘制在一张图上，通过目视检查和功率谱分析来检查MHR的昼夜节律。与显示出占主导地位的昼夜节律的雏鸡不同，鸸鹋雏鸟的昼夜节律不明显。
