EFFECTS OF PULSED ULTRASOUND ON THE FROG-HEART .1. THRESHOLDS FOR CHANGES IN CARDIAC-RHYTHM AND AORTIC PRESSURE
EFFECTS OF PULSED ULTRASOUND ON THE FROG-HEART .1. THRESHOLDS FOR CHANGES IN CARDIAC-RHYTHM AND AORTIC PRESSURE
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DOI：
10.1016/0301-5629(93)90057-u
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发表时间：
1993-01-01
影响因子：
2.9
通讯作者：
CARSTENSEN, EL
中科院分区：
文献类型：
--
作者：
DALECKI, D;KELLER, BB;CARSTENSEN, EL
研究表明，1.2 MHz高强度脉冲超声可改变在体蛙心脏的心率和主动脉压。这些效应的阈值发生在声压幅度约为10兆帕，脉冲长度为5毫秒时。根据心脏周期的不同阶段，超声脉冲可能会导致室性早搏，通过测量主动脉压来测量收缩强度，或者增强心肌的松弛。在1到5ms的范围内，随着脉冲长度的增加，超声的有效性增加。
High intensity pulsed ultrasound at 1.2 MHz is shown to change the cardiac rhythm and aortic pressure of frog hearts in vivo. Threshold levels for these effects occur at acoustic pressure amplitudes of the order of 10 MPa for 5 ms pulse lengths. Depending upon the phase of the heart cycle, a pulse of ultrasound either may cause a premature ventricular contraction, a reduction in the strength of contraction as measured by the aortic pressure, or an enhanced relaxation of the heart muscle. There is an increase in the effectiveness of the ultrasound with increase in pulse length in the range from 1 to 5 ms.