New Method To Identify Origin Of Ventricular Outflow Tract Arrhythmias Through Right-Sided Pericardial Leads

Objective The aimed of this work was using right chest electrocardiogram(ECG)characteristics to localize the origin of premature ventricular outflow tract arrhythmias.Methodology We selected symptomatic ventricular outflow tract premature ventricular arrhythmia(PVC)patients with confirmed diagnosis on ECG leads ?,?,and a VF presenting high peak R wave,those who have visited the First Affilicated Hospital of Dalian Medical University for catheter ablation between October 2016 to October 2017.The 12 lead ECG and right chest lead(V3R,V4 R,and V5R)ECG were obtained in each patient prior catheter ablation.Further,we divided all patients into left ventricular outflow tract(LOVT)and right ventricular outflow tract(RVOT)based on successful ablation sites.The right chest leads ECG characteristics were analyzed to predict the origin of LVOT and RVOT.Results A total of 63 PVC cases were enrolled,39(61.9%)cases included into RVOT group and 24(38.1%)cases included into LOVT group after successful ablation sites.The minimum age was 16 years old and maximum was 82 years old,whereas the mean age was 52.30 ± 15.28.The male to female ratio was 1:4,including 50 females and 13 males.The duration of PVC was 48(16-80)months and mean preoperative 24 hours Holter burden was 21.56 ± 9.16%.In this study RVOT group found;8 cases(12.7%)originated from the free wall,18 cases(28.6%)originated from the septum,and 13 cases(20.6%)from pulmonary valve flaps.Whereas LOVT group found;11 cases originated LCC(17.5%),3 cases from RCC(4.8%),2 cases from NCC(3.2%),4 cases from AMC(6.3%)and 4 cases from aortic valve area(6.3%).There were no significant differences in sex,duration of PVC,number of PVC in 24 hours Holter,PVC burden,PVC QRS wave duration in both groups.During Conventional 12-lead ECG analysis,the PVC was significantly delayed [3.5(2.5-3.5)vs.0(0-2.5),P <0.001] and the chest lead transition index was greater [0(0-1)vs.2.5(-2.875-1.0),P <0.001] in the RVOT group than LVOT group.The V1 lead was significantly smaller(37.87 ± 28.62 ms vs.106.17 ± 52.92 ms,P <0.001)and the time-ratio of R wave in V1 was lower(0.25 ± 0.18 vs.0.74 ± 0.33,P <0.001)than LOVT group respectively.However,SV2 / RV3 ratio was greater(4.07 ± 2.73 VS.0.43 ± 0.52,P <0.001)in RVOT group compared to LOVT group.The prediction of the LVOT origin before V3 lead showed 95.8% sensitivity and 96.6% specificity,whereas the positive predictive value was 67.6% and the negative predictive value was 96.6%.In the V2 lead R wave amplitude index > 30% showed the prediction of LOVT origin with sensitivity 87.5%,specificity 92.3%,positive predictive value 91.3%,and negative predictive value 90%.Furthermore,V2 lead R wave index duration > 50% showed the prediction of LVOT origin with sensitivity 70.8%,specificity 92.3%,positive predictive value 85.0%,negative predictive value 83.7%.In the SV2 / RV3 ?1.5 predicts the origin of LVOT with sensitivity 95.8%,specificity 84.6%,positive predictive value 79.3%,negative predictive value 97.1%.During right chest ECG leads recording,the V3 R lead in 39 patients of RVOT group showed 36 cases with r S or rs and 3 cases with Rs or RS waveform patterns,whereas,24 patients of LOVT group showed 13 cases with R or r,3 cases with r S or rs,6 cases with qr or q R or qrs and 1 cases with RS.In the V4 R lead,the RVOT showed 35 cases with r S or rs and 4 cases with RS or Rs waveform pattern,whereas the LOVT group showed 17 cases with R or r,6 cases with qr or q R or qrs,and 1 cases with RS pattern.In the V5 R lead,the RVOT showed 28 cases with r S or rs,1 case with RS,9 cases with r and 1 case with qr pattern.Whereas the LOVT showed 3 cases with r S or rs,1 case with RS,15 cases with Ror r and 5 cases with qr or qrs pattern on the recording.The present study found that different originations of PVC have distinctive characteristics on right chest ECG leads.RVOT group showed commonly r S or rs and less commonly RS and Rs wave form patterns.Whereas LOVT group showed frequently R or r or qr or qrs waveform,and less frequently with r S or rs.There was a significant difference in right chest ECG leads pattern while comparing between RVOT and LOVT group P < 0.001.Furthermore,the right chest V4 R R or r or qr or q Ror qrs,the sensitivity and specificity of LVOT is 95.8%,100%,the positive predictive value is 100% and the negative is 97.5%,respectively.the right chest V4 R r S or Rs or rs or RS,the sensitivity and specificity of RVOT is 100%,95.8%,the positive predictive value is 97.5% and the negative is 100%.Conclusions In this study,ventricular outflow tract PVC from different origins has distinctive characteristics that are detectable on right chest V3R-V5 R ECG leads.RVOT group showed commonly r S or rs and less commonly RS and Rs wave form patterns.Whereas LOVT group showed frequently R or r or qr or q Ror qrs waveform.According to distinctive characteristics of V4 R waveform,it is more convenient and viable to predict the origin of LVOT and RVOT.