Development and validation of a new algorithm in localizing accessory pathway in typical wolff-parkinson-white syndrome

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.

DEVELOPMENT AND VALIDATION OF A NEW ALGORITHM IN LOCALIZING ACCESSORY PATHWAY IN TYPICAL

WOLFF-PARKINSON-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

SUBJECTS AND METHODS

1 Subjects

298 patients from Jannuary, 2001 to

May, 2017 at Vietnam Heart Institute,

Bachmai Hospital

2 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)

1 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

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)

17 (9.0%)

55 (29.1%)

12 (6.3%)

25

(13.2%)

29

21(11.1%)

9 (4.8%)

10 (5.3%)

6 (3.2%)

5 (2.6%)

RL

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

* Characteristics of Delta wave polarity

in V1 lead with left or right side accessory

pathways:

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:

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%)

2 Accuracy of new ECG algorithm for localizing 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

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%): 9 patients (8.3%) had anterolateral, 5 patients (4.6%) had right lateral and 9 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 8 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, 4 patients (3.7%) had midseptal, 1 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

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 Position of transition zone

Septal pathway

Free wall pathway

Total

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 Delta wave polarity in inferior lead

Anterior pathway

Posterior pathway

Total

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

DISCUSSION

1 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

right-side AP [4]

2 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

(89.2%) While lateral free wall location pathway was most common at after that are noted (87.1%)

Some algorithms based on ECG not-yet 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]

3 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]

4 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

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

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