高频多普勒超声测定在体兔室性心动过速时颈总动脉血流特点的研究

Study on high-frequency doppler ultrasound measurement of blood flow characteristics in the common carotid artery during ventricular tachycardia in rabbits

目的研究高频多普勒超声测定心尖部起源的不同心室率室性心动过速时血流量峰值的特点。方法对心尖部进行3种不同频率S1S1(150、120、100ms)程序刺激,引发室性心动过速(室性心动过速模型从触发到结束整个过程中),同时使用线阵探头测定颈总动脉血流量峰值。结果所有32只兔经程序刺激后均能诱发室性心动过速,高频超声多普勒信号采集良好。室性心动过速时心室率在400～600次/min时,颈总动脉血流自身对照下降30%～86%。结论在体兔室速模型的程序刺激时,S1S1时频率应该选择在150～100ms之间,室速发作时,颈总动脉血流下降,下降幅度与心室率快慢成正比,心室率越快,通过颈总动脉血流量峰值越低,但不会出现断流。

Objective To study measure the peak blood flow during ventricular tachycardia with various ventricular rates arising from the apex of the heart using high-frequency ultrasound. Methods Ventricular tachycardia was induced using S1S1 programmed stimulation at three different cycle lengths （150,120,and 100 ms）,which were performed on the apex of the heart, during the entire process of the ventricular tachycardia model from induction to end,peak blood flow in the common carotid artery was also measured using linear array probes. Results After programmed stimulation,ventricular tachycardia could be induced in all 32 rabbits, and the high-frequency ultrasound doppler signal was well acquired.When the ventricular rate during ventricular tachycardia was 400-600 beats/min, the blood flow in the common carotid artery would decrease by 30%-86%. Conclusion S1S1 programmed stimulation cycle length in the rabbit model of ventricular tachycardia should be chosen between 150-100 ms,during the onset of ventricular tachycardia, blood flow in the common carotid artery decreased,its decrement was proportional to the speed of ventricular rate,the faster the ventricular rate,the lower the peak blood flow through the common carotid artery, however, interruption of blood flow would not occur.