The Value Of RWPT On Diagnosis Of Wide QRS Complex Tachycardia

Background: Wide QRS complex tachycardia (WCT) are common clinicalcardiovascular emergencies, including Ventricular Tachycardia, SupraventricularTachycardia with aberrant conduction, Supraventricular Tachycardia with bundlebranch block, WPW syndrome and so on. VT shows a high incidence in the WCT andit often indicates a poor prognosis. Meanwhile, it has different electrophysiologicalmechanisms, treatments and prognosis from Supra Ventricular Tachycardia (SVT) andother diseases. So it has very important clinical significance to make a differentialdiagnosis of WCT quickly and accurately. R-wave peak tim（eRWPT）is a new methodin identifying VT, has few clinical reports。Objective: To investigate the value of RWPT in differential diagnosis of WCTand improve its limitations.Method:(1) Object Selection: Fifty-two cases were collected from Institute ofCardiovascular Disease in Fujian Provincial Hospital who had Supra VentricularTachycardia underwent intracardiac electrophysiology and catheter radiofrequencyablation, including thirty-one cases of narrow QRS tachycardia and twenty-one casesof wide QRS tachycardia.(2) ECG Collection: Thirty-one cases of narrow QRStachycardia were stimulated by300ms and500ms perimeter to analog VT in rightheart (right upper interval, right median interval, right lower interval, right basalheart). Seventeen of them from left ventricular system, which were stimulated by300ms and500ms perimeter to analog VT in left heart (left basal heart and left freewall). Twenty-one other cases were not stimulated. Both cases were collectedsynchronous12-lead ECG of wide QRS. The number of ECG is337.All the ECGswere analysed by two cardiac electrophysiology physicians who were blinded to theoutcomes. If any discrepancies arose, the two physicians should re-analyze and gotthe consensus.(3) Measurement Method:①: Measured RWPT, ifRWPT≥50ms,diagnosed VT; if RWPT＜50ms, diagnosed SVT.②Measured RWPTand observed whether the lead aVR initial wave was R wave. If RWPT≥50ms, it wasdiagnosed as VT no matter the initial wave of lead aVR was. If RWPT＜50ms, it was diagnosed as VT when the initial wave of lead aVR was R wave and diagnosed asSVT when the initial wave was not.(4) We used intracardiac electrophysiology as thegold standard. Then calculate sensitivity, specificity, accuracy, positive predictivevalue and the negative value.Results:(1) The RWPT of two groups analoged VT showed no statistical difference(P>0.05);(2) There was a statistical difference between the RWPT of the right heartand left basal heart and the RWPT of SVT(P<0.05);(3) The RWPT of left free walland that of SVT had no statistical difference(P>0.05);(4) The sensitivity of RWPTcriterion to diagnosis VT is87.31%, the specificity76.19%. The positive predictivevalue is96.50%, and the negative is44.44%;(5) we used RWPT to diagnosis VT incombination of lead aVR initial R wave of QRS wave. The sensitivity is96.86%,specificity76.19%, accuracy94.97%. The positive predictive value is96.86%andnegative predictive value is86.00%Conclusion: RWPT has a high sensitive, specific and accurate criterion in diagnosingVT due to its easy and rapid method, and it is easy to recognize and handle. So RWPTis favorable in judging and handling emergency. But it is not applied to identify theVT from left heart and it is easy to misdiagnose WPW as VT. It needs to apply RWPTin combination of lead aVR initial R wave of QRS wave to elevate sensitivity,specificity and accuracy in diagnosing WCT from left ventricular system.