A Retrospective Study About The Effectiveness Of R Wave Peak Time In Lead ? Combined With Lead AVR Algorithm In Differential Diagnosis Of Wide QRS Complex Tachycardia

Backgrounds:Wide QRS complex tachycardia is an acute arrhythmia frequently seen in clinical conditions,whose manifestations range from mild symptoms like cardiopalmus,to lifethreatening hemodynamic disorder.In terms of origins and mechanisms,WCT can be divided into ventricular tachycardia and supraventricular tachycardia,therefore making the therapies differ significantly.A proper clinical treatment depends on a fast and accurate differential diagnosis.Currently,the algorithms for the antidiastole of WCT are either too complex to work properly or suffering from a deficiency of sensitivity and specificity.This study aims to verify that a novel method that combines R wave peak time in lead II and the first step of Vereckei's four-step method can be adopted in the differential diagnoses of WCT,meanwhile comparing it with Brugada's classical algorithm so that the clinical application value of the novel method can be proved.Objectives:By collecting the data of electrocardiograms(Holter included)of patients with wide QRS complex tachycardia diagnosed as ventricular tachycardia or supraventricular tachycardia by electrophysiological examination,clinical history or characteristic electrocardiograms,a novel method,which combines the measurement of R wave peak time on lead II with the pattern of QRS complex on lead aVR,was studied.Compared with Brugada's traditional algorithm in sensitivity,specificity,accuracy and likelihood ratio,the efficacy of the novel method in differential diagnoses of wide QRS complex tachycardia was evaluated,with its advantages and disadvantages discussed.Methods:1.From December 2013 to December 2019,70 inpatients in the Department of Cardiovascular Medicine,the second hospital of Jilin University,who met the WCT diagnostic criteria,were randomly selected.WCT diagnostic criteria:A rhythm with three or more beats,in which ventricular rate is greater than or equal to 100 times per minute,QRS pattern is consistent and QRS duration is longer than or equal to 120 ms.Inclusion criteria:(1)The diagnosis was confirmed by an intracardiac electrophysiological examination.(2)The diagnosis of VT was rest on a characteristic ECG pattern such as atrioventricular separation,ventricular capture or ventricular fusion wave,while no bundle branch blocks are seen.(3)The diagnosis of VT was rest on a previous history of myocardial infarction,of which the time of onset is before the emergence of WCT,with other possible reasons of arrhythmia excluded.No bundle branch blocks are seen.2.The ECG data(including Holter)of WCT patients at the time of onset were collected,including: R wave peak time in lead II(RWPT),QRS wave pattern in lead aVR(whether an initial R wave is present)and V1-V6,maximum RS interval in lead V1-V6.About the measurement of RWPT: Make a straight line perpendicular to the baseline through the highest point of R wave in lead II.RWPT refers to the distance(40 milliseconds per millimeter)between the starting point of QRS complex and the intersection of the above straight line and the baseline.About the measurement of RS interval: Make a straight line perpendicular to the baseline through the nadir of S wave in any precordial leads.RS interval refers to the distance(40 milliseconds per millimeter)between the starting point of QRS complex and the intersection of the above straight line and the baseline.3.The ECG of the collected cases were diagnosed by two experienced ECG specialists separately according to Brugada's algorithm and the novel method.If the diagnosis results of the two doctors were different,the third ECG specialist will continue to analyze and judge.The diagnosis numbers of VT and SVT were recorded respectively.On this basis,the two diagnosis algorithms were compared and analyzed by statistical methods.Brugada's algorithm: If any of the following is present,a diagnosis of ventricular tachycardia shall be given,otherwise a diagnosis of supraventricular tachycardia shall be given:No RS wave is present in the precordial leads;The maximum RS interval of precordial leads is greater than 100ms;Atrioventricular separation is present;QRS waves in V1 and V6 are similar to those in ventricular tachycardia(right bundle branch block with R,QS or RS in V1;R-S ratio in V6 less than 1 or R,QS,QR in V6;left bundle branch block with R wave duration longer than 30 ms,RS duration longer than 60 ms or descending branch faltering in V1;QS or QR in V6).RWPT combined with lead aVR algorithm: If RWPT is longer than or equal to 50 ms,or RWPT is shorter than 50 ms with an initial R wave in lead aVR,a diagnosis of VT shall be given.Otherwise a diagnosis of SVT shall be given.Compared with gold standards mentioned above,the clinical data of VT and SVT patients were studied.The sensitivity,specificity,accuracy,likelihood ratio and 95% coincidence interval of this novel algorithm and Brugada's algorithm were calculated and compared.Results:(1)Among the 70 WCT patients,48 were diagnosed as VT,22 as SVT with aberrant conduction or ventricular pre-excitation(such as reverse atrioventricular reentrant tachycardia).(2)There is no significant difference in age and gender ratio between VT and SVT group(P>0.05).The proportion of a previous organic heart history in VT group was higher than that of SVT group,and the average left ventricular ejection fraction in VT group was lower than that of SVT group.The RWPT of VT group was significantly longer than that of SVT group,and the ratio of presence of an initial R wave in lead aVR of VT group was significantly higher than that of SVT group(P < 0.05).(3)When Brugada's algorithm was adopted for diagnosis,51 of the 70 WCT patients were diagnosed as VT and 19 as SVT.There are 45 true positive cases,6 false positive cases,16 true negative cases and 3 false negative cases.In conclusion,Brugada's algorithm has a sensitivity of 93.75%,a specificity of 72.73% and an accuracy of 87.14%.The positive likelihood ratio is 3.44 and the negative likelihood ratio is 0.09.(4)When the novel algorithm was adopted for diagnosis,54 of the above 70 WCT patients were diagnosed as VT and 16 as SVT.There are 46 true positive cases,8 false positive cases,14 true negative cases and 2 false negative cases.In conclusion,the sensitivity,specificity and accuracy of the novel algorithm are 95.83%,63.64% and 85.71% respectively in the diagnosis of VT.The positive likelihood ratio is 2.64 and the negative likelihood ratio is 0.07.(5)In terms of VT diagnosis,there is no significant difference between Brugada's algorithm and the novel algorithm in sensitivity,specificity and accuracy.Conclusion:RWPT combined with lead aVR algorithm can be adopted in the differential diagnoses of WCT.There is little difference between the novel method and Brugada's traditional algorithm in sensitivity,specificity and accuracy.As the former does not need precordial lead to work properly,it is simpler and more convenient in clinical operation,and it is suitable for quick determination under emergency conditions.