The Differential Diagnosis Value Of The Ratio Of Vi/Vt In Surface ECG For Wide QRS Complex Tachycardia

Background:Wide QRS complex tachycardia(WCT) is a common cardiovascularemergency.It concludes various kinds of arrhythmia of different pathogenies andelectrophysiology mechanisms.It can be induced by coronary heart disease,myocardiopathy,electrolyte disturbances,drug intoxication and so on,it also occur inhealthy youth.Differential diagnosis of WCT quickly and accurately is very important todirect clinical treatment.Objective:To analyze the value of the surface ECG on differential diagnosis of WCT byusing the ratio of initial excite velocity to terminal excite velocity(Vi/Vt) of Vereckei foursteps flowchart retrospectively in order to get the value of the differential diagnosis of thismethod,whether it can identify the malignant arrhythmia correctly in time and preventsudden cardiac death.Methods:(1)Object selection：Select81patients whose ECG is WCT in hospital fromJanuary2005to September2011.All patients were confirmed by electrophysiologicstudy.(2)Measurements:Ratio of Vi/Vt is initial40milliseconds excite velocity to terminal40milliseconds excite velocity.If the ratio of Vi/Vt≤1,diagnose VT, If the ratio ofVi/Vt>1,diagnose SVT.(3)Electrocardiogram analysis:Every ECG is measured andanalyzed by doctor in charge of cardiovascular system who don't know the results ofECG,every patient has no less than one ECG which is recorded well.Results:In81WCT patients,62patients are confirmed VT by electrophysiologic study,24cases Vi/Vt>1,38cases Vi/Vt≤1, sensitivity61.3%,specificity78.9%,coincidence65.4%.19patients are confirmed SVT,15cases Vi/Vt>1,4cases Vi/Vt≤1, sensitivity78.9%,specificity61.3%,coincidence65.4%.Conclusions:The ratio of Vi/Vt can be used to differentiate WCT.It is a direct-viewing, convenient and atraumatic differential method.But it can misdiagnose SVT with bypass toVT,and left bypass or right bypass may lead to different results.It has good diagnosticvalue for VT from right ventricle.But for VT from left ventricle,it has a high misdiagnosisrate.To unite with other methods can elevate the diagnostic precision.