心肌收缩的频率依赖性倍周期分枝

Frequence-Dependent Period-Doubling Bifurcation in Cardic Muscles Contraction

用电场刺激离体蟾蜍心肌收缩 ,观察到心肌收缩张力随刺激频率增大而产生倍周期分枝现象 ,且观察到收缩张力的递次相关 ,证明了心肌收缩在刺激频率达到一定水平时是一个混沌系统 .

The acticle investigated the contraction of isolated toad's cardic muscle strip stimulated with electric field.It was observed that contractive force of the cardic muscle increased and showed a serious of period doubling bifurcation with increase of stimulating frequency .It was also found that contractive force at each beat related with it's predecessor beat in orderly and the forces showed high to low(or low to high) altering change.The result implies that cardic contraction become to a chaotic dynamics system when frequency of stimulation reachs to some level.The result can also give an explanation to some clinical signs such as alternative pulses in heart failure or in arrhythmia.