Abstract：ObjectiveTo study the sympathovagal balance before the onset of ventricular tachycardia(VT) in the patients with repetitive monomorphic idiopathic ventricular tachycardia(RMIVT). MethodsWe made ambulatory electrocardiographic recordings from 20 patients with RMIVT. Thirty minutes before the onset of 56 clusters of nonsustained episodes of VT(preceded by more than 1 hour of sustained sinus rhythm), we dynamically analyzed the changes of each index of heart rate variability(HRV) every five minutes. ResultsThirty minutes before the onset of VT, the standard deviation of differences between adjacent RR intervals(SDSD) in full range gradually increased while the lowfrequency(LF) power and the average RR interval in sinus rhythm progressively reduced, all with statistically significant differences(P<0.05). SDSD began to obviously increase after the first 15 minutes while LF started to markedly decrease from the same time point. The average RR interval in sinus rhythm was observed reducing significantly after the first 5 minutes. ConclusionThe occurrence of VT in patients with RMIVT is related to the dysfunction of autonomic nerve. It primarily manifests itself by the activation of sympathetic nerve and timedependence, without obvious change of tension of vagus nerve.
2018, Vol. 27 
