Objective To investigate the role of spontaneous premature beats in the differential diagnosis of short RP supraventricular tachycardia(SVT). Methods ECG data of 49 cases of spontaneous premature beats with short RP SVT were retrospectively analyzed. The mechanism of SVT was revealed when spontaneous premature beats appeared on the same map as SVT

in order to provide a "non-invasive electrophysiological examination" effect for premature beats. Results According to the ECG manifestations of spontaneous premature beats in SVT

the mechanism of SVT was confirmed in 26 cases

including 10 cases of AVRT

15 cases of AVNRT and 1 case of AT.Conclusions Careful analysis and reasonable explanation of ECG manifestations of spontaneous premature beats combined with SVT can play a role of "non-invasive electrocardiographic examination" and have high practical value.