Study On The Value Of Ventricular Premature Location In Outflow Tract By Electrocardiogram Of Ventricular Premature Beat

Introduction:Preventricular contraction（premature ventricualr contraction,PVC）is one of the most common arrhythmias in the clinic^[1]due to ectopic pacing points（ectopic pacemaker,EP）within the ventricular muscle.Patients mainly show symptoms of panic,occasionally show chest tightness,for the total number of ventricular premature patients,most do not need special treatment,can be given oral drug treatment,reduce the number of premature beats,improve symptoms.whereas for patients with 24-hour ventricular premature load（Ventricular premature beat load,VPBL）of more than 10%,drug or surgical treatment may be considered.excessive ventricular pre-contraction can cause the possibility of tachyarrhythmic cardiomyopathy（tachyarrhythmic cardiomyopathy,TC）,manifested in cardiac deformation,enlargement,and later manifestations of heart failure.PVC can be seen in normal people or in patients with organic cardiomyopathy（Organic cardiomyopathy,OC）,occurring in less normal people PVC most of the prognosis is better,while patients with organic heart disease,especially those associated with organic heart disease,such as ventricular premature myocardial infarction,heart failure related ventricular premature majority prognosis is relatively poor,and even have the risk of R on T ventricular fibrillation^[2].Functional PVC,with less ventricular premature load can be conservatively treated,patients with organic heart disease,and patients with more ventricular premature load can choose surgical treatment.As a result,the principles of PVC,treatment vary according to for failure,different mechanisms,and different location sources.generally,drugs are difficult to fundamentally correct PVC,radiofrequency ablation（radiofrequency ablation,RA）remains the only way to cure PVC at present^[3].As the only way to cure PVC,radiofrequency ablation is still facing the test,such as radiation injury during operation,long operation time,easy recurrence after operation and complications of heart rupture.Therefore,it is the most important link of preoperative preparation and the important premise to ensure the success of the operation to judge the location area of the target accurately according to the body surface electrocardiogram before operation.according to statistics,most of the origin sites of the PVC originate from the outflow tract（outflow tract,OT）of the left and right ventricles.therefore,the purpose of this study is to study the characteristics of the origin electrocardiogram PVC the outflow tract,so as to guide the operation during the operation,reduce the amount of radiation exposure,shorten the operation time and reduce the complications.Objective:PVC is one of the most common arrhythmias in clinical practice.ventricular premature（ventricular septum,VS）,the origin of ventricular septum with less ventricular early load,has less effect on cardiac function,while free wall ventricular premature（free wall,FW）with more ventricular early load has more effect on patients,which can easily cause abnormal left and right ventricular synchronism,cardiac deformation,and later cardiac function decline^[4].The only way to cure the PVC is radiofrequency ablation,and the exposure of X line during the operation,excessive operation time,repeated myocardial injury,and various complications are still the problems encountered in radiofrequency ablation.It is very important to have accurate and fast ablation targets,complete the operation and reduce the complications.By analyzing the characteristics of the PVC,we can accurately judge the origin of the PVC,so as to guide our intraoperative treatment and reduce the above problems.because the PVC of outflow tract origin is the most common origin location at present^[5],this study mainly studies the characteristics of early different region origin of outflow tract in different leads,so as to judge the specific location of the target according to the body electrocardiogram,so as to shorten the operation time,reduce unnecessary ablation,and reduce the various risks of surgery to a lower level.Methods:From January 2017 to September 2019,132 PVC patients who met the inclusion criteria were admitted to the Department of Cardiology,Affiliated Hospital of Jilin University and treated by radiofrequency ablation.Collect and complete the patient’s general clinical information,cardiac ejection fraction,ventricular diameter,etc.the time limit of QRS wave was measured by analyzing the PVC electrocardiogram of patients.the time limit of QRS wave was measured whether there were memory,R wave amplitude,electrocardiogram chest lead R/S moving lead.the difference of electrocardiogram of different origin sites was analyzed.the sensitivity,specificity,accuracy,positive predictive value,recessive predictive value of various amplifications were counted,and the area under ROC curve was used to predict the sensitivity.Results:Radiofrequency ablation was performed in 21 cases of left ventricular outflow tract（Left ventricular outflow tract,LVOT）and 72 cases of right ventricular outflow tract RVOT（RVOT）.Different outflow tract chambers were divided into two groups.The R/S migration leads（R leads with amplitude/wave amplitude greater than 1）were compared in each group.the R/S migration of the chest lead under the PVC is often earlier than that under R/S sinus rate,but when originated from the RVOT,the migration of the chest lead under the PVC is often later than that under the sinus law.sensitivity was 72.22%,specificity 80.00%,accuracy 77.42%,positive predictive value98.11%and negative predictive value 50.00%RVOT predicting the origin of premature beats when the anterior thoracic lead migration was later than the sinus rate.sensitivity 61.90%,specificity 91.67%,accuracy 84.95%,positive predictive value 68.42%and negative predictive value 89.19%LVOT the origin of premature beats when the anterior thoracic lead was moved earlier than the sinus rate.A sensitivity of 78.57%,specificity 85.71%,accuracy 80.95%,positive predictive value91.67%and negative predictive value 66.67%were used to predict the origin RVOT of premature beats with ratio less than 0.6.At the ratio greater than 0.6,the sensitivity of the origin LVOT of premature beats was 85.71%,the specificity was 78.57%,the accuracy was 80.95%,the positive predictive value was 66.67%,and the negative predictive value was 91.67%.the left coronary sinus early（Left coronary sinus,LCS）and the right coronary sinus early（Right coronary sinus,RCS）were divided into two groups.to compare the differences between the two groups,the sensitivity of the left coronary sinus early originating from the left ventricular outflow tract was88.89%,specificity 85.71%,accuracy 87.5%,positive predictive value 88.89%and negative predictive value 85.71%AVL the lead amplitude was greater than the lead amplitude.the sensitivity to predict its early ventricular origin from the right coronary sinus of the left ventricular outflow tract was 71.43%,specificity 77.78%,accuracy 75%,positive predictive value 71.43%and negative predictive value 77.78%.the sensitivity and special of various indexes to predict the early origin of lv outflow tract were judged by the area under the ROC curve using the area under the ROC curve AVL/AVR the prediction of the QS amplitude of the lead is 0.833,while the area under the ROC curve with the two-lead amplitude greater than the three-lead amplitude is 0.968.meanwhile,the anterior thoracic lead migration R/S left coronary sinus origin chamber was mostly before V2 lead,while the anterior thoracic lead migration of right coronary sinus origin was relatively late.There are two groups according to the origin of the right ventricular outflow tract wall and the origin of the right ventricular outflow tract interval.The results show that the QRS wave time limit is narrow,the QRS wave is kept in mind,and the AVR/AVL amplitude ratio is statistically significant to predict the origin of the right ventricular outflow tract.the following wall leads present cadence waves to determine the sensitivity of the ventricular premature origin from the right ventricular outflow tract to the wall is86.21%,specificity 81.40%,accuracy 83.33%,positive predictive value 75.76%,negative predictive value 89.74%.The sensitivity of the ventricular premature origin at the interval of the right ventricular outflow tract was 88.37%,the specificity was75.86%,the accuracy was 83.33%,the positive predictive value was 84.44%,and the negative predictive value was 81.48%.The sensitivity and specificity of the specific location of the right ventricular outflow tract of the early riser source were judged by using the time limit of the area under the ROC curve to predict the QRS wave.The area under the curve was 0.938,which had high sensitivity and specificity.Conclusion:1、The premature beat migration earlier than sinus rate indicated LVOT,the premature beat migration later than sinus rate indicated RVOT..2、When the sinus rate and premature beats shift occur in the same lead,the origin of ventricular premature beats is determined by V2 R wave amplitude/QRS wave amplitude)/（sinus rhythm R wave amplitude/QRS wave amplitude）,when the ratio of 0.6 indicates the origin of ventricular premature beats RVOT,when the ratio of 0.6 indicates the origin of ventricular premature beats originated in LVOT.3、The lower wall leads of the outflow chamber are all upright R waves,and the amplitude of the R wave is obviously larger than the sum of the early amplitude of the non-flow chamber,and the AVR、AVL is all QS,and the sum of the negative wave amplitudes of the AVL lead and the AVR lead is obviously larger than the sum of the corresponding amplitude of the non-flow chamber early.4、The I lead can be used to judge the premature beat,and the free wall lead is usually accompanied by cadence,and the QRS wave time limit of the free wall origin is longer than the QRS wave time limit of the spacer origin,while the Q wave amplitude of the lead is gt;AVL lead,while the early lower wall lead of the spacer chamber is sharp,and the QRS wave time is shorter than that of the free wall.5、The amplitude of the ventricular early AVL lead Q wave of the origin of the left coronary sinus is higher than that of the AVR wave amplitude,while the lower wall lead 3 lead R wave amplitude>2 lead R wave amplitude.whereas the ventricular early origin of the right coronary sinus was opposite.As far as migration is concerned,the ventricular premature migration of the origin of the left coronary sinus is mostly before the V2 lead,while the ventricular premature migration of the origin of the right coronary sinus is relatively late.