论文部分内容阅读
目的探讨链霉素对心肌梗死(简称MI)大鼠离体心脏牵张时心律失常的影响。方法36只wistar大鼠随机分为正常对照组、链霉素组、MI组、MI+链霉素组。离体心脏经Langendorff灌流后,通过改变水囊容积,以△V=0.1,0.2,0.3ml对心室牵张5s,观察牵张效应30s,记录90%单相动作电位时程(MAPD90)、室性早搏(PVB)及室性心动过速(VT)的次数。结果牵张使正常对照组及MI组MAPD90显著延长(P<0.05或0.01),其中MI组在相应牵张幅度下其MAPD90增加更为显著(与正常对照组比较,P<0.01;如△V=0.3ml,从63.2±4.95ms到55.67±4.39ms)。链霉素对基础状态下MAPD90无影响(P>0.05),但可使牵张后已延长的MAPD90显著缩短(P均<0.05;如MI组与MI+链霉素组,△V=0.2ml,从58.09±4.27ms到53.1±3.64ms)。正常及MI组PVB和VT发生率随△V的增加而增加,且后者高于前者。链霉素使两组PVB发生率显著下降,并可显著抑制VT的发生(P<0.005)。结论MI后牵张更有助于恶性心律失常的产生和维持,链霉素可以明显抑制上述现象的发生。
Objective To investigate the effect of streptomycin on cardiac arrhythmia in isolated cardiac surgery in rats with myocardial infarction (MI). Methods Thirty - six wistar rats were randomly divided into normal control group, streptomycin group, MI group and MI + streptomycin group. After the Langendorff perfusion, the ventricular volume was distorted by △ V = 0.1,0.2,0.3ml for 5s. The distraction effect was observed for 30s. The 90% single-phase MAPD90 was recorded. Premature beats (PVB) and ventricular tachycardia (VT) frequency. Result Distraction significantly increased MAPD90 in normal control group and MI group (P <0.05 or 0.01), and MAPD90 in MI group increased more significantly under corresponding stretch amplitude (P <0.01 compared with normal control group, such as △ V = 0.3 ml, from 63.2 ± 4.95 ms to 55.67 ± 4.39 ms). Streptomycin had no effect on MAPD90 in basal state (P> 0.05), but it could shorten the prolonged MAPD90 after stretch (all P <0.05). For example, MI and MI + streptomycin group, △ V = From 58.09 ± 4.27 ms to 53.1 ± 3.64 ms). The incidence of PVB and VT in normal and MI group increased with the increase of △ V, and the latter was higher than the former. Streptomycin significantly reduced the incidence of PVB in both groups and significantly inhibited the occurrence of VT (P <0.005). Conclusion Stretching after MI is more helpful for the generation and maintenance of malignant arrhythmia. Streptomycin can significantly inhibit the above phenomena.