Objectives: To develop a simple algorithm for localizing accessory pathways (APs) in the typical Wolff-Parkinson-White (WPW) syndrome using 12-lead electrocardiogram (ECG) and to test the accuracy of the newly built algorithm prospectively.
Journal of military pharmaco-medicine No7-2017 DEVELOPMENT AND VALIDATION OF A NEW ALGORITHM IN LOCALIZING ACCESSORY PATHWAY IN TYPICAL WOLFFPARKINSON-WHITE SYNDROME Chu Dung Si*; Pham Quoc Khanh**; Tran Van Dong** SUMMARY Objectives: To develop a simple algorithm for localizing accessory pathways (APs) in the typical Wolff-Parkinson-White (WPW) syndrome using 12-lead electrocardiogram (ECG) and to test the accuracy of the newly built algorithm prospectively Subjects and methods: 298 patients with typical WPW syndrome were enrolled The ECG parameters of 189 patients with a single anterograde AP that were confirmed by successful radio frequency (RF) catheter ablation were analysed to build a new ECG algorithm for localizing APs Then this algorithm was tested prospectively in other 109 patients comparing with the localization of APs by RF ablation Results: In 189 patients analyzed: the sensitivity and specificity of Delta wave polarity in V1 in predicting left or right APs were 98.3% and 92.2%, respectively; the sensitivity and specificity of QRS transition in predicting septal or lateral APs were 87.8% and 97.1%, respectively; the sensitivity and specificity of Delta wave polarity in inferior leads in predicting anterior or posterior APs were 100% and 88.7%, respectively The validation of the new algorithm based on the above ECG parameters in other 109 patients showed the sensitivity of 87.8% and the specificity of 100% Conclusion: Delta wave polarity in V1 and inferior leads combined with QRS complex transition were used to develop a new ECG algorithm for localizing AP This new algorithm can be used to localize accessory pathways with high accuracy * Keywords: Wolff-Parkinson-White syndrome; Algorithm; 12-lead electrocardiogram INTRODUCTION Wolff-Parkinson-White (WPW) syndrome associated with an accessory AV connection (called Kent Bundle); the 12-lead ECG is characterized by a shortened PR, prolonged QRS, with Delta wave [1, 2] Nowadays, radiofrequency catheter ablation (RCFA) of accessory pathway (AP) requires precise localization of the AP along the mitral and tricuspid annulus (gold standard) [2] 12-lead ECG is the first step for localization of AP in patients with WPW syndrome, still now The data obtained from the ECG parameters can be helpful in planning and shortening the RCFA and x-ray procedure [2] Some algorithms based on ECG criteria have been published to predict locations of accessory pathways However, many studies were known to be difficult to ablate as compared to those in other locations, some ECG algorithms had difficult parameters in using or only for some locations Therefore, the purpose of this study was to: Analyze the 12-lead ECG of accessory pathway localization’s successful RCFA to develop new ECG algorithm using simple parameters and test this algorithm to predict accessory pathway location * School of Medicine and Pharmacy, Vietnam National University, Hanoi ** Vietnam Heart Institute, Bachmai Hospital Corresponding author: Chu Dung Si (chudungsi@gmail.com) Date received: 25/06/2017 Date accepted: 11/08/2017 58 Journal of military pharmaco-medicine no7-2017 SUBJECTS AND METHODS Subjects 298 patients from Jannuary, 2001 to May, 2017 at Vietnam Heart Institute, Bachmai Hospital Methods Observational, cross-sectional, retrospective and prospective study 189 patients with typical WPW syndrome who had a single anterograde AP identified by successful radio frequency catheter ablation were enrolled to build a new ECG algorithm for localizing APs using simple parameters from January, 2001 to June, 2016 Then this algorithm was tested prospectively in 109 patients and compared with the location of accessory pathway’s successful ablation by RF from June, 2016 to May, 2017 WPW syndrome which was defined as the 12-lead ECG was characterized by a shortened PR interval < 120 milliseconds, prolonged QRS duration ≥ 110 milliseconds with a Delta wave Secondary ST and T wave changes which are directed opposite to the major Delta wave and QRS vector [1] Localization of accessory pathways was identified by successfully ablated by RCFA (gold standard) [2] * Statistical analysis: Using IBM SPSS 21.0 software for analyzing data RESULTS The study population consists of 298 patients, 155 males (52%) and 143 females (48%), with mean age of 43.0 ± 14.7 years (from 18 to 80 years of age) Characteristics of 12-lead ECG for localization of accessory pathways The study population consists of 189 patients (group I), 99 males (52.4%) and 90 females (47.6%) with mean age of 42.7 ± 14.6 years (2.6%) 17 (9.0%) (4.8%) (3.2%) RL 10 (5.3%) 21(11.1%) 25 29 (15.3%) 55 (29.1%) (13.2%) 12 (6.3%) Figure 1: Results of normal annulus position of location (group I) (LA: Left anterolateral; LL: Left lateral; LP: Left posterolateral; LPS: Left posterolateral; RPS: Right posterlateral; RP: Right posterolatearal; RL: Right lateral; RA: Right anterolateral; RAS: Right Anteroseptal; RMS: Right midseptal) 59 Journal of military pharmaco-medicine No7-2017 Among 189 accessory pathways, left sided accessory pathway was found in 109 patients (57.7%) and right sided accessory pathways in 80 patients (42.3%) We found that 65 patients (34.4%) had septal accessory pathways, 84 patients (44.4%) had left free wall sites and 40 patients (21.2%) had right free wall sites Anterior group had Delta wave (+) that was most common at least 2/3 inferior lead, was found in 31/31 patients (100%) and posterior group had Delta wave (-) that was most common at least 2/3 inferior lead found in 81/87 patients (93.1%) * Characteristics of Delta wave polarity in V1 lead with left or right side accessory pathways: The study population consists of 109 patients (group II), 56 males (51.4%) and 53 females (48.6%) with mean age of 43.6 ± 14.9 years Left side group had positive Delta wave that was most common at V1 lead was found in 106/109 patients (97.2%) and right side group had negative Delta wave that was most common at V1 lead was found in 67/80 patients (83.8%) * Transition characteristics of the QRS complex on 12-lead ECG with location: Classified transition of septal location was most common at V1, V2 lead (between V2 and V3) found in 58/65 patients contributing 89.2% among total number of septal AP While classified transition of lateral free wall location was most common at after V1, V2 (V3 V6)/before V1 found in 108/124 patients contributing 87.1% among total number of lateral location * Characteristics of Delta wave polarity in at least 2/3 inferior lead with anterior or posterior group: Accuracy of new ECG algorithm for localizing accessory pathways Among 109 patients, accessory pathways was most common location as left sided accessory pathways was found in 57 patients (52.3%) and right sided accessory pathways had 52 patients (47.7%) Right side free wall was 23 patients (21.1%): patients (8.3%) had anterolateral, patients (4.6%) had right lateral and patients (8.3%) had right posterolateral Left side free wall was 45 patients (41.3%): 12 patients had anterolateral, 25 patients (24.0%) had left lateral and patients (7.3%) had left posterolateral Septal accessory pathways was found in 41 patients (37.6%): 23 patients (21.1%) had right posteroseptal, 13 patients (11.9%) had left posteroseptal, patients (3.7%) had midseptal, patients (0.9%) had anteroseptal * Localization of left or right side accessory pathways by Delta wave polarity in V1 lead: Table 1: Delta wave positive/negative in V1 with left/right accessory pathways Location Delta wave polarity at V1 Left side pathway Right side pathway Total Positive Delta wave at V1 57 61 Negative Delta wave at V1 47 48 Total (n) 58 51 109 60 Journal of military pharmaco-medicine no7-2017 Accuracy of the algorithm for localizing APs in left side or right side pathway by Delta wave positive or negative at V1 was very significantly high, giving a sensitivity of 98.3%, specificity of 92.2%, PPV of 93.4% and NPV of 97.9% * Localization of septal of free wall accessory pathways group by transition characteristics of the QRS complex on 12-lead ECG: Table 2: Transition characteristics of the QRS complex with septal or lateral locations Location of AP Septal pathway Free wall pathway Total V1, V2/V2 - V3 36 38 After V1, V2 ( V3 - V6)/before V1 66 71 41 68 109 Position of transition zone Total (n) Accuracy of the algorithm for localizing APs in septal or lateral sites pathway by transition characteristics of the QRS complex at V1, V2 or after V1, V2 was very significantly high, giving a sensitivity of 87.8%, specificity of 97.1%, PPV of 94.7% and NPV of 93% * Localization of anterior or posterior accessory pathways group by the Delta wave polarity in at least 2/3 inferior lead on 12-lead ECG: Table 3: Delta wave polarity in at least 2/3 inferior lead (DII, DIII, aVF) Location Anterior pathway Posterior pathway Total Positive Delta wave in at least 2/3 inferior 22 28 Negative Delta wave in at least 2/3 inferior 47 47 22 53 75 Delta wave polarity in inferior lead Total (n) Accuracy of the algorithm for localizing APs in anterior or posterior sites by positive or negative Delta wave at V1 was very significantly higher, giving a sensitivity of 100%, specificity of 88.7%, PPV of 78.6% and NPV of 100% Overall, accuracy of new ECG algorithm for localizing accessory pathways sites were high accuracy Table 4: Sensitivity, specificity, PPV and NPV value of the proposed algorithm for accessory pathway site in 109 patients Accessory pathway site (n = 109) Se (%) Sp (%) PPV (%) NPV (%) Right side or left side pathways 98.3% 92.2% 93.4% 97.9% Anterior or posterior accessory pathways 100% 88.7% 78.6% 100% Septal or lateral accessory pathways 87.8% 97.1% 94.7% 93% 61 Journal of military pharmaco-medicine No7-2017 DISCUSSION Characteristics of Delta wave polarity in V1 lead with left or right septal Characteristics of electrocardiogram in a patient with left side pathway had strongly positive Delta waves at V1 lead are noted (97.2%) while right side pathway had strongly negative Delta waves at V1 leasd are noted (83.8%) This is very useful in selecting the approach of the catheter which is the vein or artery All right-sided AP were ablated with the use of transvenous atrial approach through the femoral vein while left-side AP were ablated with retrograde arterial approach If this approach failed, the pathway was ablated by using antegrade transeptal approach [2] Some ECG algorithms have been published to predict locations of left-sided or right-sided accessory pathway by positive of negative Delta wave [1, 2] Besides, some other studies showed that diagnosis of left or right-side accessory pathway by other ECG parameters such as Noriko was used with R/S ratio < 0.5 or R/S > 0.5 in V1 lead that can be predicted right or left-side AP [3] and D’ Avila was used to positive or negative QRS complex in V1 that can be diagnosed left or rightside AP [4] Transition characteristics of the QRS complex on 12-lead ECG with septal or lateral location Characteristics of electrocardiogram in a patient with septal location pathway was most common at V1, V2 lead are noted 62 (89.2%) While lateral free wall location pathway was most common at after that are noted (87.1%) Some algorithms based on ECG notyet finding different between anteroseptal with right anterolateral APs, difficult in posteroseptal with posterolateral (left or right) However, many studies showed that transition of QRS complex can be used to predict locations of septal or free wall accessory pathway [1, 5, 6] Characteristics of Delta wave polarity in at least 2/3 inferior lead (DII, DIII, aVF) with anterior or posterior AP group Characteristics of electrocardiogram in a patient with anterior group pathway had strongly positive Delta waves in at least 2/3 inferior that are noted (100%) While posterior group pathway had strongly negative Delta waves in at least 2/3 inferior leads (II, III, aVF) are noted (93.1%) Some ECG algorithms have been published to predict locations of anterior or posterior accessory pathway by positive or negative Delta wave in inferior as below [1, 6, 7] However, some studies only focused on some positions in anterior and posterior accessory [7] Accuracy of new ECG algorithm for localizing accessory pathways We developed a new algorithm using some simple ECG parameters as left side or right side pathways by positive/ negative Delta wave at V1 lead, anterior or posterior sites accessory pathways by Journal of military pharmaco-medicine no7-2017 positive/negative Delta waves in at least 2/3 inferior, septal or lateral sites accessory pathways by transition QRS complex at V1, V2 or after V1, V2 lead Then this algorithm was tested prospectively in 109 patients comparing with the location of accessory pathway’s successful ablation by RF Calculation for sensitivity, specificity, PPV and NPV of the diagnosed algorithm for accessory pathway sites were high accuracy (table 3, 4) For the left side or right side pathways by positive/negative Delta wave at V1 lead; Chern-En Chang (1995) showed that Se of 94.4% and Sp of 87.5% [8]; Thosmas Rostock proposed to left side of right side pathways by R/S ratio on V1, aVR, aVL with Se of 95%, Sp of 100% and PPV of 98% [9] Septal or lateral accessory pathways by transition QRS complex at V1, V2 or after V1, V2 lead The result of Muhammad’s study (2008) was: Se of 97% and Sp of 95% [10] For the anterior or posterior accessory pathways by positive/negative Delta waves in inferior, Muhammad showed that Se and Sp from 85 - 100% [10] CONCLUSION We have developed a new algorithm in localizing accessory pathway and validated it We found that the left side had Delta wave positive was most common at V1 lead (97.2%) and right side had Delta wave negative that was most common at V1 lead (83.8%) Classified transition of septal location was most common at V1, V2 lead (89.2%) while classified transition of lateral free wall location was most common at after V1 V2(V3 - V6)/before V1 (87.1%) Anterior group with positive Delta wave was most common at least 2/3 inferior lead (100%) and posterior group with negative Delta wave was most common at least 2/3 inferior lead (93.1%) The new algorithm was proved to be high accuracy as sensitivity (from 87.8% to 100%), specificity (88.7 to 97.1%), positive predictive value (78.6% to 94.7%) and negative predictive value (93% to 100%) and could facilitate radiofrequency ablation in patients with left side or right sided AP REFERENCES Borys Surawicz et al Chou’s electrocardiography in clinical practice: adult and pediatric Elservier Saunders 2008 Basiouny Tarex et al Prospective validation of A sezer ECG algorithm for localization of accrssory pathways in patients with Wolff-Parkinson-White syndrome AAMJ 2012, 10, Suppl-2 Noriko Taguchi, Yasuya Inden et al A simple algorithm for localizing accessory pathways in patients with Wolff-ParkinsonWhite syndrome using only the R/S ratio Journal of Arrhythmia 2013 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Delta wave polarity in at least 2/3 inferior lead with anterior or posterior group: Accuracy of new ECG algorithm for localizing accessory pathways Among 109 patients, accessory pathways was most... developed a new algorithm in localizing accessory pathway and validated it We found that the left side had Delta wave positive was most common at V1 lead (97.2%) and right side had Delta wave negative... localization of accessory pathways in patients with Wolff-Parkinsonwhite syndrome from a comprehensive 64 analysis of Delta waves and R/S ratio during sinus rhythm The American Journal of Cardiology