Clinical And Electrophysiological Characteristics Of Outflow Tract Ventricular Arrhythmias In Patients Undertaken Catheter Ablation

Objective Analysis the clinical and electrophysiological characteristics of outflow tract ventricular arrhythmias(OTVA)in patients who have undertaken catheter ablation.And to discuss the superiority and inferiority in the origin of OTVA with known electrocardiogram(ECG)indexes such as the transitional zone(TZ)index,S-wave amplitude in lead V2 divided by R-wave amplitude in lead V3(V2S/V3R),and R-wave duration index and R/S-wave amplitude index.Provide a reference basis for clinical diagnosis and treatment.Methods Retrospective analysis was performed on the data of 54 inpatients admitted to the general hospital of Ningxia Medical University who had undertaken catheter ablation on January 1,2011,solstice,and December 31,2017 and who were confirmed to be OTVA by electrophysiology in the operation center.The clinical and electrophysiological characteristics of these patients were analyzed,as well as the preoperative 12-lead surface ECG of these patients.R-wave duration index,R/S-wave amplitude index,V2S/V3 R index,and TZ index were observed,measured and calculated.The sensitivity,specificity,positive predictive value and negative predictive value of ECG for preoperative prediction of OTVA origin site were determined by the above indicators.Results 1.There were 54 hospitalized OTVA patients who had undertaken catheter ablation,including 24 males(44.44%)and 30 females(55.56%).Patients with right ventricular outflow tract(RVOT)origin were aged(45.33±14.25)years,and patients with left ventricular outflow tract(LVOT)origin were aged(44.33±15.53)years.49 patients(90.74%)had initial symptoms(such as palpitations and shortness of breath)before surgery,and 10 patients(18.52%)had syncope.There was no significant difference in baseline data between the two groups.2.According to the gold standard of electrophysiological results in catheter ablation,all the eligible cases were divided into: 36 cases with the origin of right ventricular outflow tract,accounting for 66.67% of all OTVA patients;LVOT originated in 18 cases,accounting for33.33%.Among them,23 cases of RVOT originated from the septum,7 cases from the free wall,5 cases from the junction of the septum and free wall,and 1 case from the pulmonary valve,respectively accounting for 64%,19%,14% and 3% of the patients(36 cases)with RVOT ventricular arrhythmia.LVOT originated in 5 cases of left coronary cusp,6 cases of right coronary cusp,1 case of none coronary cusp,5 cases between left and right coronary cusp,and 1 case under aortic valve.3.For the patients in the RVOT origin group and the LVOT origin group,the indicators of the body surface ECG included the TZ index(0.64±0.95 VS 1.64±1.11,t=-7.875,P<0.01),the R-wave duration index(0.40±0.11 VS 0.57±0.13,t=4.971,P<0.01),and the R/S-wave amplitude index(0.26±0.24 VS 2.06±2.49,t=4.352,P<0.01),and V2S/V3 R index(4.10±2.27 VS 1.31±2.14,t=-4.342,P<0.01)showed statistically significant differences between the two groups.4.When identifying the OTVA originated from the left and right ventricular outflow tract,the sensitivity of the three indicators was the TZ index(94%)>V2S/V3 R index(89%)and >R-wave duration index and R/S-wave amplitude index(83%).The specificity was V2S/V3 R index(94%)>R-wave duration index and R/S-wave amplitude index(89%)>TZ index(81%).The accuracy of V2S/V3 R index is the highest,reaching 93%.The TZ index has the highest negative predictive value,at 97%。Conclusion1.Female patients with OTVA may be slightly more than male patients.2.The RVOT is the most common type of OTVA,and the origin of the septum is themost common.3.V2S/V3 R index specificity and accuracy were the highest when ECG indicators were used to identify ventricular arrhythmias originated from the left and right outflow tracts.TZ index of < 0 can more accurately exclude that the OTVA originated from the RVOT,but the specificity and accuracy of its determination originated from the LVOT are lower than the R-wave duration index and R/S-wave amplitude index and V2S/V3 R index.4.V2S/V3 R index has a high predictive value for the origin site of ventricular arrhythmia.