体外冲击波致心律失常机制的实验研究

目的　探讨体外冲击波 (extracorporealshockwave ,ESW)诱发心律失常的机制。方法　以杂种犬右室心尖部作为ESW的靶点 ,ESW冲击犬心脏前、后分别测定心房和心室的舒张期阈值、相对不应期、有效不应期及不应期离散 ,并记录ESW冲击犬心脏前、后各 4h及冲击心脏过程中出现的心律失常。结果　ESW冲击犬心脏后 ,心房和心室的舒张期阈值、有效不应期、相对不应期及不应期离散均无明显改变 (P >0 .0 5 ) ;ESW冲击心脏过程中只出现室性早搏 ,ESW冲击心脏前、后未出现任何心律失常。结论　早搏的机制可能与折返、自律性增高无关 ,而是由ESW直接诱发。

Experimental studies of mechanisms of extracorporeal shock wave inducing arrhythmias

Objective To study mechanisms of arrhythmias induced by ESW. Methods ESW were discharged at apexes of the right ventricles of hybrid canines. Atrial and ventricular diastolic thresholds, relative refractory periods and effective refractory periods and refractory period dispersions were determined before and after discharges of ESW; arrhythmias were recored for 4 hours before and after discharges of ESW and in the course of discharges. Results After discharges of ESW, Atrial and ventricular diastolic thresholds, effective refractory periods and relative refractory periods and refractory period dispersions remained unchanged (P>0.05). There were only ventricular premature beats induced by ESW in the course of discharges;and there were no any arrhythmias before and after discharges of ESW. Conclusions Mechanisms of premature beats maybe have nothing to do with reentry and automaticity increase, but were only due to ESW itself.