Objective To investigate the clinical value of three ECG algorithms for the differentiation diagnosis of wide QRS complex tachycardia（WCT）. These three algorithms included a VR single lead four step method（short named as a VR-lead method）

ventricular tachycardia score（short named as VT-score method） and limb lead algorithm（LLA）. Methods Twelve-lead electrocardiogram（ECG） was selected from 41 patients with WCT. The nature of the tachycardia was confirmed by intracardiac electrophysiology. The diagnosis was made by two experts in ECG diagnosis using these three diagnostic procedures. The sensitivity

specificity

accuracy

Youden index and consistency of the three methods were compared. Results The accuracy of the a VR-lead method

the VT-score method

and the LLA in the diagnosis of VT was 80.5%

48.8%

and 78.1%. The sensitivity was 87.9%

42.4%

and78.8%; the specificity was 50.0%

75.0%

and 75.0%; and the Youden index was 37.89%

17.4%

and 53.8%. The kappa value of the a VR-lead method

VT-score method

and LLA was 0.485

0.015

and 0.662

respectively.Conclusions The accuracy and sensitivity of a VR-lead method were higher than those of LLA and VT-score method.The Youden index of LLA was higher than those of a VR-lead method and VT-score method. The specificity of LLA was consistent with that of VT-score method

which was higher than that of a VR-lead method. Between the two experts

LLA was the most consistent

followed by a VR-lead method

and then the VT-score method. The three identification methods have their own advantages and disadvantages

which can be used together in clinical practice.