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Differentiating the origin of outflow tract ventricular arrhythmia using a simple novel approach
Abstract
Numerous ECG criteria have been proposed for identifying the localization of outflow tract ventricular arrhythmias (OT-VA). However, in some cases it is difficult to accurately localize the origin of OT-VA using the surface ECG.
To assess a simple criterion for localization of OT-VA during electrophysiology study.
We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal, (the QRS-RVA interval), in 66 patients (31 male, age 53.3 ±14.0, RVOT origin 37) referred for ablation of symptomatic outflow tract PVCs. We validated prospectively this criterion in 39 patients (22 male, age 52 ±15; RVOT origin 19).
Compared to patients with RVOT-PVCs, the QRS-RVA interval was significantly longer in patients with LVOT-PVCs (70±14 vs. 33.4±10, p<0.001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms has a sensitivity, specificity, positive and negative predictive values of 100%, 94.6%, 93.5%, 100% respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, positive and negative predictive values of 94.7%, 95%, 95%, 94.7% respectively. Combined together a QRS-RVA interval ≥49 ms has a sensitivity, specificity, positive and negative predictive values of 98%, 94.6%, 94.1%, 98.1% respectively, for prediction of an LVOT origin.
A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study, however the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.
Copyright © 2015. Published by Elsevier Inc.
... An accurate prediction of RVOT and LVOT origins of OTVT can optimize the CA strategy, reduce ablation duration, and avoid operative complications. Previous studies (Kamakura et al., 1998;Hachiya et al., 2000;Ito et al., 2003;Joshi and Wilber, 2005;Tanner et al., 2005;Haqqani et al., 2009;Zhang et al., 2009;Betensky et al., 2011;Yoshida et al., 2011Yoshida et al., , 2014Cheng et al., 2013Cheng et al., , 2018Nakano et al., 2014;Efimova et al., 2015;He et al., 2018;Xie et al., 2018;Di et al., 2019;Enriquez et al., 2019;Yamada, 2019) propose several criteria or models to estimate RVOT and LVOT origins. However, these results have been limited by sample size, scope of studies, ECG measurement efficiency, and generalizability of the models. ...
... For all cases, QRS measurements were performed on an isolated PVC representative of the clinical VT before the induction of sustained VT and compared with the SR QRS complex. All measurements above were used to compare our approach against methods from 12 prior studies (Kamakura et al., 1998;Zhang et al., 2009;Betensky et al., 2011;Yoshida et al., 2011Yoshida et al., , 2014Cheng et al., 2013Cheng et al., , 2018Nakano et al., 2014;Efimova et al., 2015;He et al., 2018;Xie et al., 2018;Di et al., 2019). ...
... The classification confusion matrix for these three methods shows correct and incorrect frequency counts in Supplementary Section A and Table 3. Furthermore, we compared our approach against related methods from 12 prior studies (Kamakura et al., 1998;Zhang et al., 2009;Betensky et al., 2011;Yoshida et al., 2011Yoshida et al., , 2014Cheng et al., 2013Cheng et al., , 2018Nakano et al., 2014;Efimova et al., 2015;He et al., 2018;Xie et al., 2018;Di et al., 2019). ACC, F 1 -score, SE, SP, positive predictive value, negative predictive value, and AUC were used to compare performances and are shown in Table 3. ...
Introduction
Multiple algorithms based on 12-lead ECG measurements have been proposed to identify the right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT) locations from which ventricular tachycardia (VT) and frequent premature ventricular complex (PVC) originate. However, a clinical-grade machine learning algorithm that automatically analyzes characteristics of 12-lead ECGs and predicts RVOT or LVOT origins of VT and PVC is not currently available. The effective ablation sites of RVOT and LVOT, confirmed by a successful ablation procedure, provide evidence to create RVOT and LVOT labels for the machine learning model.
Methods
We randomly sampled training, validation, and testing data sets from 420 patients who underwent successful catheter ablation (CA) to treat VT or PVC, containing 340 (81%), 38 (9%), and 42 (10%) patients, respectively. We iteratively trained a machine learning algorithm supplied with 1,600,800 features extracted via our proprietary algorithm from 12-lead ECGs of the patients in the training cohort. The area under the curve (AUC) of the receiver operating characteristic curve was calculated from the internal validation data set to choose an optimal discretization cutoff threshold.
Results
The proposed approach attained the following performance: accuracy (ACC) of 97.62 (87.44–99.99), weighted F1-score of 98.46 (90–100), AUC of 98.99 (96.89–100), sensitivity (SE) of 96.97 (82.54–99.89), and specificity (SP) of 100 (62.97–100).
Conclusions
The proposed multistage diagnostic scheme attained clinical-grade precision of prediction for LVOT and RVOT locations of VT origin with fewer applicability restrictions than prior studies.
... Rapid ECG interpretation requires expertise and could be facilitated with a computerassisted method to automatically localize the origin of early ventricular activation during an invasive EP study and ablation. Various algorithms based on the 12-lead ECG have been proposed for localizing the origin of early ventricular activation in human studies [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . However, a simple intraprocedural automatic localization system is lacking. ...
... To estimate the performance of patient-specific site localization using the patient's own EA coordinates, localization of pacing sites was performed. Pacing at multiple endocardial sites had been performed in each patient, and 'target' sites were identified as those that had between 5 and 15 pacing site neighbors within radius of 10,15,20,25,30,35,40,45, 50 mm. The neighboring pacing sites were used to calculate patient-specific regression coefficients by combining their known sites and ECG integrals from leads III, V2 and V6. ...
... † Indicates that site of origin/ablation site was only approximately localized. 10,15,20,25,30,35,40,45, and 50 millimeters were identified. For each selected "target" site, EA coordinates of its each training set together with 3 ECG variables (lead III, V2, and V6) were used to calculate patient-specific regression coefficients and these were then used, in turn, to predict the location (in terms of EA coordinates) of the "target" site; the mean localization error of this prediction was calculated for each set of "target" sites (in millimeters). ...
Background:
To facilitate ablation of ventricular tachycardia (VT), an automated localization system to identify the site of origin of left ventricular activation in real time using the 12-lead ECG was developed. The objective of this study was to prospectively assess its accuracy.
Methods:
The automated site of origin localization system consists of 3 steps: (1) localization of ventricular segment based on population templates, (2) population-based localization within a segment, and (3) patient-specific site localization. Localization error was assessed by the distance between the known reference site and the estimated site.
Results:
In 19 patients undergoing 21 catheter ablation procedures of scar-related VT, site of origin localization accuracy was estimated using 552 left ventricular endocardial pacing sites pooled together and 25 VT-exit sites identified by contact mapping. For the 25 VT-exit sites, localization error of the population-based localization steps was within 10 mm. Patient-specific site localization achieved accuracy of within 3.5 mm after including up to 11 pacing (training) sites. Using 3 remotes (67.8±17.0 mm from the reference VT-exit site), and then 5 close pacing sites, resulted in localization error of 7.2±4.1 mm for the 25 identified VT-exit sites. In 2 emulated clinical procedure with 2 induced VTs, the site of origin localization system achieved accuracy within 4 mm.
Conclusions:
In this prospective validation study, the automated localization system achieved estimated accuracy within 10 mm and could thus provide clinical utility.
... Recently, new non-invasive methods for the detection of IVA origins have been proposed based on the analysis of ECG signals. Several studies have already proven a strong relationship between the features of electrocardiogram (ECG) and the locations where IVAs stem from [16][17][18][19], and several approaches have been developed to find the IVAs' origins based on this relationship [20][21][22][23][24]. For example, in [20], a threshold based on the amplitude of ECG R wave in lead I was used to identify the IVA origin. ...
Idiopathic ventricular arrhythmia (IVAs) is extra abnormal heartbeats disturbing the regular heart rhythm that can become fatal if left untreated. Cardiac catheter ablation is the standard approach to treat IVAs, however, a crucial prerequisite for the ablation is the localization of IVAs' origin. The current IVA localization techniques are invasive, rely on expert interpretation, or are inaccurate. In this study, we developed a new deep-learning algorithm that can automatically identify the origin of IVAs from ECG signals without the need for expert manual analysis. Our developed deep learning algorithm was comprised of a spatial fusion to extract the most informative features from multichannel ECG data, temporal modeling to capture the evolving pattern of the ECG time series, and an attention mechanism to weigh the most important temporal features and improve the model interpretability. The algorithm was validated on a 12-lead ECG dataset collected from 334 patients (230 females) who experienced IVA and successfully underwent a catheter ablation procedure that determined IVA's exact origins. The proposed method achieved an area under the curve of 93%, an accuracy of 94%, a sensitivity of 97%, a precision of 95%, and an F1 score of 96% in locating the origin of IVAs and outperformed existing automatic and semi-automatic algorithms. The proposed method shows promise toward automatic and noninvasive evaluation of IVA patients before cardiac catheter ablation.
... Catheter ablation is a common curative therapy for OTVA patients with and without structural heart disease when drugs are ineffective or have unacceptable side effects (3,4). Accurate prediction of a right ventricular outflow tract (RVOT) vs. left ventricular outflow tract (LVOT) origin of OTVA can direct the catheter ablation strategy, thereby reducing ablation duration and avoiding operative complications (5)(6)(7). Current algorithms that only rely on the standard 12-lead electrocardiogram (ECG) to identify OTVAs are limited to the cardiac rotation caused by the physical shape and cannot achieve the desired accuracy (8)(9)(10). ...
Background and aims
Standard 12-lead electrocardiogram (ECG) patterns combined with the anatomical cardiac long-axis angle revealed by chest X-ray can prevent the influence of cardiac rotation, physical shape, and lead position, so it may be an ideal means to predict the origin of the outflow tract (OT) ventricular arrhythmias (OTVAs) for ablation procedures. The study explores the value of this strategy in identifying the origin of OTVA.
Methods
This study was conducted using a retrospective cohort and a prospective cohort of consecutive patients at two centers. The anatomical cardiac long-axis angle was calculated by measuring the angle between the cardiac long-axis (a line joining the apex to the midpoint of the mitral annulus) and the horizontal plane on a chest X-ray. The V2S angle was calculated as the V2S amplitude times the angle. We ultimately enrolled 147 patients with symptomatic OTVAs who underwent successful radiofrequency catheter ablation (RFCA) (98 women (66.7%); mean age 46.9 ± 14.7 years; 126 right ventricular OT (RVOT) origins, 21 left ventricular OT (LVOT) origins) as a development cohort. The new algorithm was validated in 48 prospective patients (12 men (25.0%); mean age 48.0 ± 15.8 years; 36 RVOT, 12 LVOT origins).
Results
Patients with RVOT VAs had greater V2S, long-axis angle, and V2S angle than patients with LVOT VA (all P < 0.001). The cut-off V2S angle obtained by receiver operating characteristic (ROC) curve analysis was 58.28 mV° for the prediction of RVOT origin (sensitivity: 85.7%; specificity: 95.2%; positive predictive value: 99.1%; negative predictive value: 52.6%). The AUC achieved using the V2S angle was 0.888 ( P < 0.001), which was the highest among all indexes (V2S/V3R: 0.887 ( P < 0.016); TZ index: 0.858 ( P < 0.001); V1-2 SRd: 0.876 ( P < 0.001); V3 transition: 0.651 ( P < 0.001)). In the prospective cohort, the V2S angle had a high overall accuracy of 93.8% and decreased the procedure time ( P = 0.002).
Conclusion
V2S angle can be a novel measure that can be used to accurately differentiate RVOT from LVOT origins. It could help decrease ablation duration and radiation exposure.
... In another study by Kimie et al.,26 V2 transition ratio was significantly higher in PVCs originated from LVOT group than from RVOT and V2 transition ratio could predict LVOT origin with sensitivity of 83% and specificity of 88%. Efimova et al. 8 ...
Background:
Electrocardiography (ECG) is now proposed as a simple and cost-effective tool to determine the location of arrhythmias before ablation. We aimed to examine the value of the QRS onset of outflow tract PVC in V1 and V2 leads recorded in fourth, third, and second intercostal spaces to differentiate two main origins for premature ventricular contraction (PVC) including right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT).
Methods:
In this prospective cohort study, a total of 58 patients were studied, from whom a surface ECG was obtained using V1 and V2 leads in the fourth, third, and second intercostal spaces. ECG and Electrophysiology studie (EPS) data were then recorded and compared to determine the sensitivity and specificity of QRS onset in locating arrhythmias. The reciever operating characterictic (ROC) curve analysis was applied to test diagnostic performance.
Results:
Based on the time of PVC initiation in each of the V1 and V2 leads in the fourth intercostal space, if PVC is recorded earlier in the V1 lead, its source in 95.8% of the patients is RVOT and if PVC preceded the V2 lead, 70.59% of the patients had PVC from LVOT. Comparing of QRS onset in V1 and V2 leadsrecorded from third% and and second intercostal spaces had considerable sensitivity and specificity to determine the origin of the outflow tract PVC (81.82 and 94.12%, respectively).
Conclusion:
Simultaneous recording of outflow tract PVCs from second third and fourth intercostal spaces and comparing their onset can determine the left and right outflow tract PVCs with high sensitivity and specificity.
... Threedimensional (3D) electroanatomic mapping (EAM) to accurately identify critical sites of origin is very helpful for the success of IVA ablation (5). A number of 12-lead electrocardiogram (ECG) algorithms (6)(7)(8)(9) and noninvasive ECG imaging (ECGI) approaches (10,11) have been used to pre-procedurally predict IVA source sites. However, using 12-lead ECG algorithms to interpret the IVA origin sites or chamber of interest may provide insufficient spatial resolution and accuracy, resulting in the need for frequent ectopy to combine activation mapping (12). ...
Objectives
The objective of this study was to present a new system, the Automatic Arrhythmia Origin Localization (AAOL) system, which used incomplete electroanatomic mapping (EAM) for localization of idiopathic ventricular arrhythmia (IVA) origin on the patient-specific geometry of left ventricular, right ventricular, and neighboring vessels. The study assessed the accuracy of the system in localizing IVA source sites on cardiac structures where pace mapping is challenging.
Background
An intraprocedural automated site of origin localization system was previously developed to identify the origin of early left ventricular activation by using 12-lead electrocardiograms (ECGs). However, it has limitations, as it could not identify the site of origin in the right ventricle and relied on acquiring a complete EAM.
Methods
Twenty patients undergoing IVA catheter ablation had a 12-lead ECG recorded during clinical arrhythmia and during pacing at various locations identified on EAM geometries. The new system combined 3-lead (III, V2, and V6) 120-ms QRS integrals and patient-specific EAM geometry with pace mapping to predict the site of earliest ventricular activation. The predicted site was projected onto EAM geometry.
Results
Twenty-three IVA origin sites were clinically identified by activation mapping and/or pace mapping (8, right ventricle; 15, left ventricle, including 8 from the posteromedial papillary muscle, 2 from the aortic root, and 1 from the distal coronary sinus). The new system achieved a mean localization accuracy of 3.6 mm for the 23 mapped IVAs.
Conclusions
The new intraprocedural AAOL system achieved accurate localization of IVA origin in ventricles and neighboring vessels, which could facilitate ablation procedures for patients with IVAs.
... The comparison among two feature extraction methods and cardiologists (shown in Table 2 ) shows that the performance of the AI model with the automated feature extraction method is superior. The comparison of our approach against methods from 12 prior studies 6,[11][12][13][14][15][16][17][18][19][20][21] shows that our algorithm achieved the highest performance scores. Additionally, we evaluated the general classification capability of each criterion proposed by previous studies using the database in this study. ...
... This is in line with prior studies indicating that VAs originating from the septum of the outflow tracts are likewise commonly misclassified by other algorithms since they might have exits at both sides. 20 Whether photographic documentation and integration of the actual precordial lead positions or a comparison between the QRS morphology of intrinsically conducted beats and PVCs for the given electrode positions could further increase the accuracy of the automated algorithm will have to be assessed in further studies. ...
Background:
Radiofrequency catheter ablation of idiopathic ventricular arrhythmias (VA) is performed to eliminate symptoms and to prevent or reverse arrhythmia-induced cardiomyopathy. Pre-procedural prediction of the chamber of VA origin is critical for patient counseling, procedure planning and guidance of invasive mapping.
Objective:
We aimed to assess the performance of manual expert versus automated 12-lead ECG analysis in the prediction of VA origin.
Methods:
Patients with ablation of idiopathic VA and sustained success were included. The VA origin was defined as the site where ablation caused arrhythmia suppression. Standard baseline 12-lead ECGs with documentation of the VA were analyzed manually in a blinded fashion by 3 electrophysiologists and 3 electrophysiology fellows. In addition, the same standard 12-lead ECG was analyzed by an automated computer algorithm using a vectorcardiographic approach.
Results:
Thirty-eight patients (median age 47 [IQR 37-58]; 68% female) were enrolled. The VA originated from the right ventricle in 24 (63%) and the left ventricle in 14 (37%) patients. The electrophysiologists and EP fellows identified the VA chamber of origin with a similar accuracy of 73% and 72% (p=0.72). The automated algorithm showed a higher accuracy of 89% (p=0.03 compared to electrophysiologists and EP fellows). This resulted in a sensitivity of 95% and specificity of 86%.
Conclusion:
While the manual ECG analysis of the standard 12-lead ECG by both electrophysiologists and EP fellows correctly identified the chamber of VA origin in around 75% of cases, an automated vectorcardiographic computer algorithm achieved an accuracy of 89% with clinically acceptable diagnostic parameters. This article is protected by copyright. All rights reserved.
... Twelve-lead electrocardiograms (ECG) of the VA originating in the ventricular outflow tract show a waveform indicating a left bundle branch block (LBBB) and inferior axis deviation. Since the left ventricular outflow tract is close to the right ventricular outflow tract anatomically, various electrocardiographic methods for differentiating ventricular outflow VA have been developed [11][12][13]. As the TA is close to the MA at the ventricular posterior septum, VA originating from the TA in the posterior septal region (TAPS-VA) and that originating from the MA in the posterior septal region (MAPS-VA) show similar ECG waveforms. ...
Purpose
Ventricular arrhythmia (VA) arising from the tricuspid annulus in the posterior septum (PS) (TAPS-VA) has similar electrocardiographic characteristics as VA arising from the mitral annulus in the PS (MAPS-VA) because the two locations are adjacent. We examined the electrocardiographic characteristics that differentiate MAPS-VA from TAPS-VA and the efficacy of catheter ablation.
Methods
We studied 13 patients whose VAs were successfully ablated in the TAPS (n = 7) and MAPS (n = 6).
Results
QRS morphologies of both groups were characterized by left and right bundle block morphologies in lead V1, superior axis deviation, and precordial transition at ≤ lead V3 in nine patients. Compared with TAPS-VA, MAPS-VA had (1) R < S wave in lead II, (2) precordial transition in lead V2, (3) s-wave in lead V6, and (4) slurred initial part of the QRS complex in the precordial leads, e.g., [4a] pseudo delta wave ≥ 34 ms, [4b] intrinsicoid deflection time ≥ 85 ms, and [4c] maximum deflection index ≥ 0.55. Patients who met ≥ 2 of (1)–(3) and any of [4a]–[4c] could be classified as having MAPS-VA, with a sensitivity and specificity of 100%. VA recurred in one patient in the TAPS group during the median follow-up of 7 (interquartile range 6 to 15.5) months.
Conclusions
VA arising from the PS has superior axis deviation, and left and right bundle block morphologies with relatively early precordial transition. MAPS-VA can be differentiated from TAPS-VA based on electrocardiographic characteristics. This study provides useful information for treatment involving catheter ablation for VA arising from the PS.
Background: We previously developed a non-invasive approach to localize the site of early left ventricular activation origin in real time using 12-lead ECG, and to project the predicted site onto a generic LV endocardial surface using the smallest angle between two vectors algorithm (SA).
Objectives: To improve the localization accuracy of the non-invasive approach by utilizing the K-nearest neighbors algorithm (KNN) to reduce projection errors.
Methods: Two datasets were used. Dataset #1 had 1012 LV endocardial pacing sites with known coordinates on the generic LV surface and corresponding ECGs, while dataset #2 included 25 clinically-identified VT exit sites and corresponding ECGs. The non-invasive approach used “population” regression coefficients to predict the target coordinates of a pacing site or VT exit site from the initial 120-m QRS integrals of the pacing site/VT ECG. The predicted site coordinates were then projected onto the generic LV surface using either the KNN or SA projection algorithm.
Results: The non-invasive approach using the KNN had a significantly lower mean localization error than the SA in both dataset #1 (9.4 vs. 12.5 mm, p < 0.05) and dataset #2 (7.2 vs. 9.5 mm, p < 0.05). The bootstrap method with 1,000 trials confirmed that using KNN had significantly higher predictive accuracy than using the SA in the bootstrap assessment with the left-out sample ( p < 0.05).
Conclusion: The KNN significantly reduces the projection error and improves the localization accuracy of the non-invasive approach, which shows promise as a tool to identify the site of origin of ventricular arrhythmia in non-invasive clinical modalities.
Background:
Consistent data from several studies have shown that catheter ablation of frequent premature ventricular complexes (PVCs) results in substantial improvement in left ventricular ejection fraction (LVEF), left ventricular diastolic function, and left atrial volume and mechanics. However, the effects of catheter ablation of PVCs on atrial electromechanical properties have not been documented yet.
Aims:
In the present study, we investigated the short-term effects of radiofrequency catheter ablation (RFCA) of outflow tract PVCs on atrial electromechanical delay (EMD).
Methods:
A total of 71 subjects with idiopathic outflow tract PVCs who underwent RFCA were included. Interatrial and intra-atrial EMDs were measured by tissue Doppler imaging before and 3 months after catheter ablation.
Results:
The study population was divided into normal ejection fraction (EF) and low-EF subgroups according to their LVEF. In all study groups, substantial improvement was found in lateral electromechanical coupling time (PA), septal PA, right ventricular PA, interatrial EMD, left-sided intra-atrial EMD, and right-sided intra-atrial EMD. No treatment heterogeneity was observed when comparing low-EF and normal-EF subgroups with respect to atrial EMDs (interatrial EMD, interaction p = .29; left-sided intra-atrial EMD, interaction p = .13; right-sided intra-atrial EMD, interaction p = .88).
Conclusion:
RFCA of outflow tract PVC has a favorable early effect on intra- and inter-atrial EMDs irrespective of preprocedural LVEF.
Background
Radiofrequency catheter ablation (CA) is an efficient antiarrhythmic treatment with a class I indication for idiopathic ventricular arrhythmia (IVA), only when drugs are ineffective or have unacceptable side effects. The accurate prediction of the origins of IVA can significantly increase the operation success rate, reduce operation duration and decrease the risk of complications. The present work proposes an artificial intelligence-enabled ECG analysis algorithm to estimate possible origins of idiopathic ventricular arrhythmia at a clinical-grade level accuracy.
Method
A total of 18,612 ECG recordings extracted from 545 patients who underwent successful CA to treat IVA were proportionally sampled into training, validation and testing cohorts. We designed four classification schemes responding to different hierarchical levels of the possible IVA origins. For every classification scheme, we compared 98 distinct machine learning models with optimized hyperparameter values obtained through extensive grid search and reported an optimal algorithm with the highest accuracy scores attained on the testing cohorts.
Results
For classification scheme 4, our pioneering study designs and implements a machine learning-based ECG algorithm to predict 21 possible sites of IVA origin with an accuracy of 98.24% on a testing cohort. The accuracy and F1-score for the left three schemes surpassed 99%.
Conclusion
In this work, we developed an algorithm that precisely predicts the correct origins of IVA (out of 21 possible sites) and outperforms the accuracy of all prior studies and human experts.
Aim
The current study aimed to establish a novel electrocardiographic (ECG) criterion for discrimination of idiopathic premature ventricular contractions (PVCs) originating from posteroseptal right ventricular outflow tract (sRVOT-p) versus right coronary cusp (RCC).
Methods
A total of 76 patients with idiopathic PVCs who underwent mapping and successful ablation were retrospectively included. Among them, 37 patients had PVCs from sRVOT-p origin and 39 patients from RCC origin. The surface ECGs during PVCs were recorded. S-R different index in V1/V3 was calculated with the following formula of 0.134*V3R-0.133*V1S.
Results
ECG characteristics showed wider total QRS duration, smaller R-wave amplitude on lead V2-V5, and larger S-wave amplitude on lead V1-V3 in sRVOT-p origin than RCC origin. Lead V3 was the most common transitional lead in two groups. Receiver operating characteristic (ROC) curve analysis showed that S-wave amplitude on lead V1 exhibited the largest AUC of 0.772, followed by the AUC of R-wave amplitude on lead V3 of 0.771. Subsequently, 0.134*V3R-0.133*V1S index was obtained by multiplication, subtraction, sum, and division of these ECG measurements, which exhibited the largest AUC of 0.808. The optimal cut-off value was −0.26 for differentiating RCC from sRVOT-p origin, with the sensitivity of 78.4% and specificity of 77.8%. Moreover, 0.134*V3R-0.133*V1S index was superior to previous criteria in analysis of PVCs originating from sRVOT-p and RCC.
Conclusions
0.134*V3R-0.133*V1S is a novel ECG criterion to discriminate sRVOT-p from RCC origin in patients with idiopathic PVCs, which may provide guidance for approach of radiofrequency catheter ablation.
Background
Many electrocardiography (ECG) criteria have been proposed for the localization of outflow tract premature ventricular contractions (PVCs); however, in some cases, it is difficult to accurately localize the origin of PVCs using the surface ECG. The authors aimed to study the QRS–right ventricular apex (RVA) interval measured during electrophysiological study and its role in the differentiation between different sites of origin of outflow tract PVCs.Methods
The study included 90 patients (81 females, mean age 37.20 ± 7.87) referred for outflow tract PVC ablation. The authors measured the interval from the onset of the earliest QRS complex of the PVCs to the distal RVA intracardiac signal (the QRS–RVA interval) during the electrophysiological study and correlated this interval with the origin of outflow tract PVCs as identified by successful ablation during the procedure.ResultsThe QRS–RVA interval was significantly longer in PVCs originating from the left ventricular outflow tract (LVOT) compared to the right ventricular outflow tract (RVOT) (67.33 ± 7.56 for LVOT PVCs vs. 37.11 ± 4.34 for RVOT PVCs, p < 0.001). Receiver operating characteristic (ROC) analysis showed that a QRS–RVA interval ≥ 48 ms predicted an LVOT origin of PVCs. A shorter interval was noted in PVCs originating from the RVOT free wall rather than the septal RVOT wall, and a shorter interval was also noted in LVOT PVCs originating from the right coronary cusp as compared to other LVOT PVCs, although these differences did not reach statistical significance.Conclusion
Measuring the QRS–RVA interval is a simple and accurate method for differentiating the origin of outflow tract PVCs during an electrophysiological study. A QRS–RVA interval ≥ 48 ms predicts an LVOT origin of PVCs rather than an RVOT origin.
Background
Idiopathic ventricular arrhythmias (IVAs) with right bundle branch block (RBBB) and superior axis commonly originate from posterior mitral annulus (PMA), the left ventricular (LV) posterior fascicle (LPF), and the LV posterior papillary muscles (PPM).
Hypothesis
Remote magnetic navigation (RMN)‐guided ablation might be safe and effective for these three origins of IVAs.
Methods
Thirty consecutive IVA patients with RBBB and superior axis (11 MPA‐IVAs, 11 LPF‐IVAs, and 8 PPM‐IVAs) were included in this study. Electrical mapping and ablation with RMN were performed in the LV through a trans‐septal approach. Navigation index, defined as the ratio of total radiofrequency (RF) time and the time from first burn to last burn, was used to determine the efficiency of RMN‐guided ablation.
Results
The overall acute success rate was achieved in 93% (PMA, 100%; LPF, 91%; PPM, 88%; p > 0.05). No complication occurred in this study. The procedure time of PPM‐IVAs group was 34 and 14 min longer when compared with MPA‐IVAs and LPF‐IVAs group, respectively, without an increase of X‐ray time. The mean navigation index was 0.45 ± 0.20. The PPM‐IVAs group had an underperforming navigation index value (0.29 ± 0.11) (p < 0.01), as longer RF time was required in the PPM‐IVAs group.
Conclusions
RMN‐guided ablation can achieve a high acute success rate for IVAs with RBBB and superior axis. The lower navigation index for PPM‐IVAs indicated that increasing the RF time and improving the catheter contact should be considered when using RMN.
Several algorithms based on 12-lead ECG measurements have been proposed to identify right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT) locations from which ventricular tachycardia (VT) and frequent premature ventricular complex (PVC) originated. However, a clinical-grade artificial intelligence algorithm is not available yet, which can automatically analyze characteristics of 12-lead ECGs and predict RVOT to LVOT origins of VT and PVC. We randomly sampled training, validation, and testing datasets from 420 patients who underwent successful catheter ablation (CA) to treat VT or PVCs, containing (340, 80%), (38, 9%), and (42, 10%) patients, respectively. We iteratively trained an AI algorithm that was supplied with 1,600,800 features extracted from 12-lead ECGs of the patients in the training cohort. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated from the internal validation dataset to choose an optimal discretization cutoff threshold. After running on the testing dataset, the proposed approach attained the following performance metrics and 95% CIs (confidence intervals), accuracy (ACC) of 97.62 (87.44 -99.99), weighted F1-score of 98.46 (90-100), AUC of 98.99 (96.89-100), sensitivity (SE) of 96.97 (82.54-99.89), and specificity (SP) of 100 (62.97-100). The proposed multi-stage diagnostic scheme attained clinical-grade precision of prediction for LVOT and RVOT locations of VT origin with fewer applicability restrictions than prior studies.
Objectives
The aim of this study was to investigate the accuracy of electrocardiographic imaging (ECGI) in localizing the origin of outflow tract ventricular arrhythmias (OTVAs) and compare its performance with that of seven published 12-lead electrocardiography (ECG) algorithms.
Methods
Patients with OTVAs who were undergoing catheter ablation were prospectively investigated. The OVTA origins were localized using both ECGI and seven 12-lead ECG algorithms, with the successful ablation site set as the gold standard. The performance of the ECGI and 12-lead ECG algorithms were compared.
Results
Twenty-seven patients were enrolled into the study. The ECGI system correctly identified the chamber of OTVA origin in 27/27 (100%) patients and the sublocalization within the right ventricular outflow tract (RVOT) in 21/22 (95.5%) patients. However, the ECG algorithms correctly diagnosed the chamber and sublocalization in only 21/27 (77.8%) patients and 13/22 (59.1%) patients, respectively, which was significantly lower compared with the ECGI system.
Conclusions
Non-invasive ECGI can accurately predict the origin of OTVAs in a manner that is superior to that of conventional 12-lead ECGs in differentiating the RVOT from the left ventricular outflow tract (LVOT) and septum from free wall in the RVOT. This provides a useful tool to guide catheter ablation.
This trial has been registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR1900025527).
Cardiac catheter ablation has shown the effectiveness of treating the idiopathic premature ventricular complex and ventricular tachycardia. As the most important prerequisite for successful therapy, criteria based on analysis of 12-lead ECGs are employed to reliably speculate the locations of idiopathic ventricular arrhythmia before a subsequent catheter ablation procedure. Among these possible locations, right ventricular outflow tract and left outflow tract are the major ones. We created a new 12-lead ECG database under the auspices of Chapman University and Ningbo First Hospital of Zhejiang University that aims to provide high quality data enabling detection of the distinctions between idiopathic ventricular arrhythmia from right ventricular outflow tract to left ventricular outflow tract. The dataset contains 334 subjects who successfully underwent a catheter ablation procedure that validated the accurate origins of idiopathic ventricular arrhythmia.
Background:
Idiopathic arrhythmias commonly arise from the septal right ventricular outflow tract (RVOT), sinuses of Valsalva (SoV), and great cardiac vein (GCV). Predicting the exact site of origin is important for preparation for catheter ablation.
Objective:
The purpose of this study was to examine the diagnostic value of noninvasive electroanatomic mapping (NIEAM) to differentiate between septal RVOT, SoV, and GCV origin and compare it to that of 12-lead electrocardiography (ECG).
Methods:
NIEAM maps (CardioInsight, Medtronic) were generated during spontaneous ventricular premature depolarizations (VPDs) and threshold pacing from septal RVOT, SoV, and GCV. Origin prediction using NIEAM was compared to algorithmic ECG criteria (maximal deflection index; V2 transition ratio) and subjective ECG evaluation.
Results:
Sixty NIEAMs (18 spontaneous VPDs and 42 pace-maps) from 31 patients (age 56 ± 16 years) were analyzed. NIEAM showed distinct conduction patterns, best visualized at the base of the heart: septal RVOT VPDs propagate toward the tricuspid annulus, depolarizing the septum from inferior to superior; SoV VPDs engage the superior septum early; and GCV VPDs move laterally along the mitral annulus, depolarizing the heart from left to right. Activation of the lateral mitral annulus >60.50 ms and the superior basal septum <22.5 ms from onset predicts RVOT and SoV origin, respectively, in 100% of cases. NIEAM was superior to maximum deflection index in predicting GCV origin (100% vs 42.2% accuracy) and superior to V2 transition ratio in predicting SoV origin (100% vs 75.9% accuracy).
Conclusion:
Arrhythmias arising from the outflow tracts follow distinct propagation patterns depending on the origin. A 2-step algorithm using activation timing by NIEAM yields 100% diagnostic accuracy in predicting origin.
Background:
View into Ventricular Onset (VIVO) is a novel ECGI system that uses 3D body surface imaging, myocardial CT/MRI, and 12‑lead ECG to localize earliest ventricular activation through analysis of simulated and clinical vector cardiograms.
Objective:
To evaluate the accuracy of VIVO for the localization of ventricular arrhythmias (VA).
Methods:
In twenty patients presenting for catheter ablation of VT [8] or PVC [12], VIVO was used to predict the site earliest activation using 12‑lead ECG of the VA. Results were compared to invasive electroanatomic mapping (EAM).
Results:
A total of 22 PVC/VT morphologies were analyzed using VIVO. VIVO accurately predicted the location of the VA in 11/13 PVC cases and 8/9 VT cases. VIVO correctly predicted right vs left ventricular foci in 20/22 cases.
Conclusion:
View into Ventricular Onset (VIVO) can accurately predict earliest activation of VA, which could aid in catheter ablation, and should be studied further.
Objectives:
This study sought to prospectively evaluate the value of a dedicated electrocardiographic posterior lead to create an anteroposterior ratio to localize premature ventricular complexes (PVCs) between the right ventricular outflow tract and left ventricular outflow tract for catheter ablation.
Background:
The anteroposterior relationship between the right and left outflow tract has not been explored for electrocardiographic localization of ventricular arrhythmia.
Methods:
Standard V5 and V6 leads were placed posteriorly and ablation was performed with activation mapping. The site of successful ablation was correlated with the ratio of the R-wave in V4 to the R-wave in V8. Normalization of the V4/V8 ratio to a V4/V8 index was achieved by dividing the V4/V8 ratio by sinus V4/V8. After determination of optimal cutoffs, comparison with V2 transition ratio and V2S/V3R was subsequently performed using receiver operating characteristic curves in a prospective validation cohort.
Results:
A total of 134 patients underwent ablation of PVCs with 2 modified posterior leads. PVCs successfully ablated from the left side had a statistically significantly higher V4/V8 ratio compared with right-sided PVCs (11.7 ± 10.6 vs. 2.3 ± 2.4, p < 0.001). At a cutoff of >3, the V4/V8 ratio had a sensitivity of 88% with a specificity of 77% for left-sided locations. At a cutoff of >2.28, the V4/V8 index had a sensitivity of 67% with a specificity of 98%. In the prospective validation cohort (n = 40), the V4/V8 ratio exhibited the highest sensitivity of 75% with a negative predictive value of 89% compared with the V4/V8 index, V2 transition ratio, and V2S/V3R. The V4/V8 index had the highest specificity of 96% with positive predictive value of 89% compared to the other predictive ratios. When analyzing cases with a V3 transition, the V4/V8 index demonstrated 100% specificity and positive predictive value.
Conclusions:
A simple modification of V5 to V8 posteriorly may provide incremental diagnostic value for localizing PVCs arising from the outflow tracts. Normalizing PVC localization criteria to the sinus rhythm results in the highest specificity when compared with other validated criteria.
Background:
Multiple intercostal recording was supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate ECG criterion for differentiating between left and right OT-VA origins.
Methods:
We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular outflow tract (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10).superior, and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, Transition zone (TZ) index, R/S amplitude ratio and R wave duration ratio were measured in the regular, superior, and inferior precordial leads.
Results:
the combined TZ index, TZ index inf was significantly smaller, while the V2 inf transition ratio was significantly larger for ACC origins than RVOT origins (P < 0.05). The area under the curve (AUC) for the combined TZ index by a receiver operating characteristic (ROC) analysis was 0.974, which was significantly larger than other parameters. A cutoff value of ≤0.25 predicting an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0.
Conclusions:
the combined TZ index outperformed other ECG criteria to differentiate left from right OT-VA origins. This article is protected by copyright. All rights reserved.
Background
Radiofrequency catheter ablation (RFCA) has been used for the ablation of premature ventricular contractions (PVCs) or ventricular tachycardia (VT). To date, the mapping and catheter ablation of the arrhythmias originating from the left ventricular outflow tract (LVOT) has not been specified. This study investigates the electrocardiogram (ECG) feature of PVCs or VT originating from the LVOT. Moreover, the treatment outcome of RFCA is analyzed.
Methods
Mapping and ablation were performed on the supravalvular or subvalvular aorta in 52 cases with PVCs/VT originating from the LVOT. The data were compared with those from 104 patients with PVCs/VT originating from the right ventricular outflow tract (RVOT). A differential procedure was prepared based on the comparison of the ECG features of PVCs/VT originating from the RVOT, LVOT, and their different parts.
Results
Among 52 cases with PVCs originating from the LVOT, 47 were successfully treated by RFCA, with a success rate of 90.38%. Several differences among the 12-lead ECG features were observed from the RVOT and LVOT in the left and right coronary sinus groups, as well as under the left coronary sinus group (left fibrous trigone): (1) If the precordial leads transition 0 are considered as the diagnostic parameters of PVCs/VT originating from the LVOT, then the sensitivity, specificity, as well as positive and negative predictive values are 94.12%, 93.00%, 87.27%, and 96.88%, respectively; (2) The analysis of different subgroups of the LVOT are as follows: (a) A mainly positive wave of r or m pattern was recorded in the lead I in 72.73% of patients in the right coronary sinus group, versus 12.90% of patients in the left coronary sinus group, and 0% in the under left coronary sinus group. (b) All patients in the right coronary sinus group presented waves of RII>RIII and QSaVR>QSaVL, whereas most patients in the other two groups showed waves of RIII>RII and QSaVL>QSaVR. (c) Most patients in the under left coronary sinus group in lead V1 had a mainly positive wave (R) (77.78%), whereas those in the right (81.82%) and left (62.50%) coronary sinus groups had mainly negative waves (rS).
Conclusions
RFCA is a safe and effective curative therapy for PVCs/VT originating from the LVOT. The 12-lead ECG features of the LVOT from different origins exhibit certain distinctions.
Several electrocardiographic (ECG) algorithms have been developed to identify the site of origin of ventricular premature contractions (VPCs) from right ventricular outflow tract (RVOT) based on pacemapping; however, their accuracy remains unclear.
We evaluated the accuracy of these algorithms in 52 consecutive patients (31 female, mean age 42.6+/-14.6 years) with successful radiofrequency ablation of RVOT-VPC as guided by 3D electroanatomical non-contact mapping (Ensite, St Jude Medical, USA) and compared with a newly proposed ECG algorithm. As guided by 3D electroanatomical mapping, the successful ablation sites of RVOT-VPC were RVOT septum (n=31), RVOT free wall (n=19), and His region (n=2). Retrospective evaluation in the initial 39 patients shows that the overall positive prediction value to identify a successful ablation site of this newly proposed ECG algorithm is 77.3% and is higher than the 73.3% by Ito et al., 73.3% by Joshi et al., and 53.8% by Dixit et al. (P>0.05). Prospective evaluation in the subsequent 13 patients also demonstrate similar high overall sensitivity (79.0%), specificity (92.7%), and positive prediction value (88.2%) to identify a successful ablation site with this newly proposed ECG algorithm.
On the basis of detail 3D electroanatomical mapping of successful ablation sites, a newly proposed ECG algorithm was developed to improve the sensitivity, specificity, and positive prediction value in identification of targeted ablation sites for RVOT-VPC.
Although several ECG criteria have been proposed for differentiating between left and right origins of idiopathic ventricular arrhythmias originating from the outflow tract (OT-VA), their accuracy and usefulness remain limited. This study was undertaken to develop a more accurate and useful ECG criterion for differentiating between left and right OT-VA origins.
We studied OT-VAs with a left bundle branch block pattern and inferior axis QRS morphology in 207 patients who underwent successful catheter ablation in the right (RVOT) (n = 154) or left ventricular outflow tract (LVOT) (n = 53). The surface ECGs during the OT-VAs and during sinus beats were analyzed with an electronic caliper. The V2S/V3R index was defined as the S-wave amplitude in lead V2 divided by the R-wave amplitude in lead V3 during the OT-VA. The V2S/V3R index was significantly smaller for LVOT origins than RVOT origins (p< 0.001). The area under the curve (AUC) for the V2S/V3R index by a receiver operating characteristic analysis was 0.964, with a cut-off value of ≤1.5 predicting an LVOT origin with an 89% sensitivity and 94% specificity. In the AUC and accuracy, the V2S/V3R index was superior to any previously proposed ECG criteria in an analysis of all OT-VAs. This advantage of the V2S/V3R over the V2 transition ratio and other indices also held true for a sub-analysis of 77 OT-VAs with a lead V3 precordial transition.
The V2S/V3R index outperformed other ECG criteria to differentiate left from right OT-VA origins independent of the site of the precordial transition. This article is protected by copyright. All rights reserved.
Aims
For successful ablation of ventricular outflow tract arrhythmia, estimation of its origin prior to the procedure can be useful. Morphology and lead placement in the right thoracic area may be useful for this purpose. Electrocardiography using synthesized right-sided chest leads (Syn-V3R, Syn-V4R, and Syn-V5R) is performed using standard leads without any additional leads. This study evaluated the usefulness of synthesized right-sided chest leads in estimating the origin of ventricular outflow tract arrhythmia.
Methods and results
This retrospective study included 63 patients in whom successful ablation of ventricular outflow tract arrhythmia was performed. Numbers of arrhythmias originating from the left ventricle, the septum of the right ventricle, and the free wall of the right ventricle were 11, 40, and 13, respectively. In one patient, two different left ventricular outflow tract origins were found. Electrocardiographic recordings from right-sided chest leads were divided into three types as follows: those in which an R > S concordance, a transitional zone, or an R < S concordance were detected. In all left arrhythmia cases, R > S concordance was observed. A transitional zone was evident in 34 of 40 cases of right ventricular outflow tract arrhythmia originating in the ventricular septum, and an R < S concordance was observed in 6 of the 40 cases. However, an R < S concordance was found in all cases of right ventricular outflow tract arrhythmia originating in the free wall.
Conclusion
Synthesized right-sided chest lead electrocardiography may be useful for estimating the origin of ventricular outflow tract arrhythmia.
It is unknown whether radiofrequency ablation (RFA) or antiarrhythmic therapy is superior when treating patients with symptomatic premature ventricular contractions.
This single center retrospective study is designed to determine the relative efficacy of RFA and antiarrhythmic drugs (AADs) on decreasing PVC burden and improving left ventricular (LV) systolic function.
Patients with frequent PVCs (>1,000/24 hours) were treated by either RFA or AADs from January, 2005 to December, 2010. Data from 24-hour Holter monitoring and echocardiography before and 6 to 12 months after treatment were compared between the 2 groups.
Of 510 patients identified, 215 (40%) underwent RFA and 295 (60%) received AADs. The reduction of PVC frequency was greater by RFA than by AADs (-21,799/24 hours vs -8,376/24 hours; P<.001). LV ejection fraction (LVEF) was significantly improved after RFA (53% to 56%; P<.001) but not after AADs (52% to 52%; P=.6). Among 121 patients with reduced LVEF, 39 (32%) had LVEF normalization to 50% or greater. LVEF was restored in 47% (25/53) of the RFA group compared with 21% (14/68) of the AAD group (P=.003). A PVC coupling interval less than 450ms, less impaired LV function, and RFA were independent predictors of LVEF normalization by multivariate analysis.
RFA appears to be more effective than AADs in PVC reduction and LVEF normalization.
Background:
To distinguish left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in idiopathic premature ventricular contractions or ventricular tachycardia (PVCs/VT) patients with transitional lead at V3 is still a challenge. We sought to develop a new electrocardiography (ECG) algorithm for distinguishing LVOT from RVOT origin in patients with idiopathic outflow tract PVCs/VT with precordial transitional lead at V3.
Methods:
We analyzed the surface ECG characteristics in a retrospective cohort of idiopathic PVCs/VT patients with transitional lead at V3 who underwent successful radiofrequency catheter ablation and developed a new surface ECG algorithm, then validated it in a prospective cohort.
Results:
A total of 82 consecutive patients (47 ± 17 years, 39% male) underwent radiofrequency catheter ablation of idiopathic outflow tract PVCs/VT between January 2006 and August 2010. Among them, 31 patients (38%) with transitional lead at V3 constituted the retrospective cohort. Based on the areas under the receiver operating characteristic curves, R-wave deflection interval in lead V3>80 ms and R-wave amplitude index in lead V1>0.30 were selected to develop the new surface ECG algorithm. It correctly identified the origin sites of eleven from 12 patients in the prospective cohort, yielding the accuracy of 91.7%.
Conclusions:
We presented a new simple surface ECG algorithm, R-wave deflection interval in lead V3>80 ms combining with R-wave amplitude index in lead V1>0.30 which can reliably distinguish LVOT from RVOT origin in idiopathic outflow tract PVCs/VT in patients with transitional lead at V3.
Purpose:
Contemporary outcome data of catheter ablation for outflow tract tachycardia (OTT) and ventricular premature beats (VPBs) are rare. The aim of this study was to describe the clinical characteristics, the acute procedure success rate, and the long-term survival of patients who underwent an ablation procedure for OTT or VPBs.
Methods:
The study was a single-center retrospective cohort study. All 82 consecutive OTT and VPB first ablation procedures between 1999 and 2009 were included. Patients with structural heart disease were excluded.
Results:
Mean age was 46 ± 13 years. Forty-three percent of the patients were male. All patients were alive after a median follow-up duration of 31 months (interquartile range, 14-65 months). Eighty-nine percent suffered from palpitations and 12 % had a history of syncope. Ventricular tachycardia was documented in 73 % and monomorphic VPBs in 99 %. Seventy-three percent of the patients were ablated in the right ventricular outflow tract, 15 % in the left ventricular outflow tract, and 12 % in the coronary cusps. Radiofrequency energy was used in 95 % of the patients, cryo energy in 9 %. Acute success was achieved in 78 %. Six patients (7 %) experienced a complication (five pericardial effusions, one pseudo-aneurysm of the femoral artery). Three patients needed pericardiocentesis (4 %).
Conclusion:
Ablation for OTT and VPB is successful in the vast majority of cases, with a low but still existing complication rate. Long-term survival was excellent, underscoring the benign nature of this arrhythmia.
Introduction: Idiopathic ventricular outflow tract tachycardia or premature ventricular contractions (OT-VTs) can originate from several different sites in the outflow tract, including the left ventricular (LV) endocardium and epicardium. The aims of this study were (1) to develop an ECG algorithm to predict the origin of OT-VT and (2) to test prospectively the accuracy of the algorithm.
Methods and Results: An algorithm was developed by correlating the 12-lead ECG findings with the catheter ablation site in 80 patients with OT-VT. The ECG characteristics of the QRS complex during the arrhythmia were analyzed. The catheter sites were verified by multiplane fluoroscopy. The outflow tract was classified into six subdivisions: right ventricular (RV) septum, RV free wall, RV near the His-bundle region, LV endocardium, left sinus of Valsalva (LSV), and LV epicardium remote from the LSV. An OT-VT originating from the LV epicardium remote from the LSV was defined as an OT-VT in which the earliest ventricular activation was recorded at the LSV and radiofrequency ablation from the LSV failed. This algorithm subsequently was tested prospectively in 88 patients. Overall sensitivity was 88% and specificity was 95%. The positive and negative predictive values were 88% and 96%, respectively.
Conclusion: We describe a new ECG algorithm having a high sensitivity and specificity to identify the optimal ablation site for idiopathic ventricular outflow tachycardia or premature ventricular contractions. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1280-1286, December 2003)
The origin of outflow tract ventricular tachycardia (OTVT) can be predicted from a surface electrocardiogram: indexes of R-wave amplitudes in leads V(1) and V(2) are used to differentiate a right origin from a left origin, while the axis of lead I differentiates an anterior origin from a posterior origin. Incorrect electrode placement is clinically common and may alter predictability of OTVTs.
To explore the influence of vertical deviation in leads V(1) and V(2) and arm lead position on the QRS morphology of OTVTs.
Vertical deviation of leads V(1) and V(2) was studied in 18 patients with OTVTs. Ventricular premature depolarization beats were recorded in the standard position, superior position, and inferior position. The effect of arm lead position was studied in a separate cohort of 16 patients: ventricular premature depolarizations were recorded with limb leads positioned over the shoulders and over the chest. The origin of tachycardia was determined by using activation mapping and confirmed by successful ablation.
Superior displacement of leads V(1) and V(2) reduced the R-wave amplitude and led to a decreased R/S ratio (0.11 ± 0.09 vs 0.17 ± 0.1; P <.01), while inferior displacement of leads V(1) and V(2) resulted in an increased R-wave amplitude and led to an increased R/S ratio (0.46 ± 0.35 vs 0.17 ± 0.1; P <.01). Anterior displacement of the arm leads from shoulders to chest resulted in the reduction in the R-wave amplitude in lead I (0.25 ± 0.30 mV vs 0.04 ± 0.43 mV; P <.05).
Small changes in electrocardiographic electrode placement markedly alter the QRS morphology of OTVTs and thus alter the predictability of OTVT origin. These deviations are well within the range of clinical application and have the potential to misdirect ablation procedures.
We sought to develop electrocardiography (ECG) criteria for distinguishing left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in patients with idiopathic outflow tract ventricular tachycardia (OTVT) and lead V(3) R/S transition.
Several ECG criteria have been proposed for differentiating left from right OTVT origin; ventricular tachycardias (VTs) with left bundle branch block and V(3) transition remain a challenge.
We analyzed the surface ECG pattern of patients with OTVT with a precordial transition in lead V(3) who underwent successful catheter ablation. Sinus and VT QRS morphologies were measured in limb and precordial leads with electronic calipers. The V(2) and V(3) transition ratios were calculated by computing the percentage R-wave during VT (R/R+S)(VT) divided by the percentage R-wave in sinus rhythm (R/R+S)(SR).
We retrospectively analyzed ECGs from 40 patients (mean age 44 ± 14 years, 21 female) with outflow tract premature ventricular contractions (PVCs)/VT. Patients with structural heart disease, paced rhythms, and bundle branch block during sinus rhythm were excluded. The V(2) transition ratio was significantly greater for LVOT PVCs compared with RVOT PVCs (1.27 ± 0.60 vs. 0.23 ± 0.16; p < 0.001) and was the only independent predictor of LVOT origin. In 21 prospective cases, a V(2) transition ratio ≥0.60 predicted an LVOT origin with 91% accuracy. A PVC precordial transition occurring later than the sinus rhythm transition excluded an LVOT origin with 100% accuracy.
The V(2) transition ratio is a novel electrocardiographic measure that reliably distinguishes LVOT from RVOT origin in patients with lead V(3) precordial transition. This measure might be useful for counseling patients and planning an ablation strategy.
Different kinds of the surface ECG limb electrode positions may affect the limb lead vector and therefore the accuracy of the 12-lead ECG in localization of outflow tract ventricular tachycardia (OTVT). This study was intended to evaluate and compare the accuracy of the standard and the modified 12-lead ECG for localization of OTVT using the current published criteria.
Twenty consecutive patients (10 men, mean age, 51.6 ± 13.4 years) with OT-VT were included. A standard ECG with the distal placement of the limb lead electrodes and a modified ECG with the limb electrodes placed on the torso were recorded during the OT-VT and were used for localization by 2 electrophysiologists who were blinded to the successful ablation site to compare the accuracy of the 2 ECGs. The R wave amplitude during OT-VT in lead I of the standard 12-lead ECG was significantly higher compared to the modified surface ECG (0.225 ± 0.145 mV vs 0.139 ± 0.111 mV, P = 0.032). The S wave in aVR during OT-VT was significantly more negative compared to the modified surface ECG (-0.682 ± 0.182 mV vs -0.527 ± 0.228 mV, P = 0.017). The rate of accurate localization of the successful ablation sites in the anterior versus posterior outflow tract by the 2 observers using standard ECG (70% and 80%) were higher compared to modified ECG (50% and 60%, P = 0.042).
The R wave amplitude in lead I and the depth of the S wave amplitude in lead aVR of the standard surface ECG during OT-VT is significantly larger compared to the modified surface ECG. As the QRS morphology of the OT-VT is usually the first clue to the possible site of successful ablation, the standard 12-lead ECG should be used for more accurate localization of the origin of the OT-VT.
Idiopathic premature ventricular complexes originating from the ventricular outflow tract: evaluation, prognosis and management The prognosis of ventricular premature complexes (VPC) in the absence of heart disease is considered benign. VPC usually originate from the right or, less commonly, left ventricular outflow tract. QRS complexes therefore usually assume a left bundle branch block and inferior axis morphology. These VPC, particularly if very frequent (> 20,000 per day), may adversely affect left ventricular function and their suppression can restore normal function. Moreover, there is a clinical overlap with arrhythmogenic right ventricular dysplasia and this diagnosis should be considered when facing a left bundle branch block shaped VPC. However, the prognosis of outflow tract VPC is good for appropriately selected patients with normal left ventricular function, absence of syncope or ventricular tachycardia, and no evidence of cardiac disease.
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Ventricular arrhythmias are known to originate from the aortic sinus of Valsalva.
The purpose of this study was to identify the characteristics associated with ventricular arrhythmias originating from the right coronary cusp-left coronary cusp (RCC-LCC) commissure.
Thirty-seven consecutive patients with ventricular arrhythmias originating from the aortic cusp region were studied. Intracardiac echocardiography and electroanatomic mapping were used to define coronary cusp anatomy and catheter position. Ventricular arrhythmias from the RCC-LCC commissure were compared with ventricular arrhythmias originating from other sites in the aortic cusp region.
Nineteen (51%) ventricular arrhythmias had an anatomic origin at the RCC-LCC commissure. Eighteen ventricular arrhythmias originated from other aortic cusp sites (4 right cusp, 7 left cusp, 3 left ventricular endocardium, 4 left ventricular epicardium anterior to aortic valve). A QS morphology in lead V(1) with notching on the downward deflection was present in 15 of 19 ventricular arrhythmias originating from the RCC-LCC commissure compared to 2 of 18 ventricular arrhythmias from other aortic cusp sites (P <.01). At the site of earliest activation, 13 of 19 patients with RCC-LCC ventricular arrhythmias had late potentials in sinus rhythm compared to 1 of 18 ventricular arrhythmias from other aortic cusp sites (P <.01). The site of successful ablation was confirmed to be above the aortic valve plane in 15 (79%) of 19 patients with RCC-LCC ventricular arrhythmias.
RCC-LCC aortic cusp ventricular arrhythmias are common and have a QS morphology in lead V(1) with notching on the downward deflection with precordial transition at lead V(3). In the majority of cases, the site of successful ablation has late potentials in sinus rhythm.
Recently, it has been reported that frequent premature ventricular contractions (PVCs) may be associated with causing heart failure in patients with left ventricular (LV) dysfunction. However, the prognostic significance of frequent PVCs in asymptomatic patients with a normal LV function is unclear.
Two hundred and thirty-nine consecutive patients presenting with frequent PVCs (>1000 beats/day) originating from the right or left ventricular outflow tract without any detectable heart disease were enrolled in the study. Structural heart disease was ruled out by echocardiography and cardiac magnetic resonance imaging, and Holter-ECG monitoring was repeated two or three times to evaluate the PVC prevalence at the initial evaluation. All patients were followed up for at least 4 years, and further observation was continued if possible.
During an observation period of 5.6 (1.7) years, no patients exhibited any serious cardiac events. Although there was no significant change in the mean LV ejection fraction (LVEF) and mean LV diastolic dimension (LVDd), there was a significant negative correlation between the PVC prevalence and DeltaLVEF (p<0.001) and positive correlation between the PVC prevalence and DeltaLVDd (p<0.001). When the development of LV dysfunction was defined as DeltaLVEF>-6%, 13 patients exhibited LV dysfunction. For the prediction of the development of LV dysfunction, PVC prevalence and LVEF at the initial evaluation were independent predicting factors (p<0.01).
Although the prognosis in patients with frequent PVCs was considered relatively benign, attention should be paid to the progression of the LV dysfunction during a long-term observation, especially in patients with a high PVC prevalence.
This report describes the clinical and electrophysiologic characteristics of 30 patients without myocardial disease who had ventricular tachycardia with the morphologic characteristics of left bundle branch block and inferior axis. The tachycardias were nonsustained in 24 patients, sustained (greater than 30 sec) in six patients, and provocable by exercise in 14 of 23 patients undergoing a standard Bruce protocol. Ventricular tachycardia was induced during electrophysiologic study in 22 of 30 patients. Programmed stimulation induced tachycardia in 10 of 30 patients, most frequently by rapid atrial or ventricular pacing. Isoproterenol infusion facilitated tachycardia induction in 13 of 23 patients. Endocardial activation mapping, performed in 10 patients, confirmed that earliest ventricular activation during tachycardia occurred at the right ventricular outflow tract on the interventricular septum. These tachycardias were unique in their responsiveness to a wide variety of antiarrhythmic drugs, including type I drugs and propranolol. During a mean follow-up of 30 months, no patient has died or experienced cardiac arrest. Two patients appear to be in spontaneous remission, and no patient has developed additional signs of cardiac disease.
To evaluate the timing of the right ventricular (RV) apical electrogram in relation to the QRS complex during ventricular tachycardia (VT), 94 episodes of sustained uniform VT were analyzed in 56 patients. The timing of the RV apical electrogram varied and could be recorded from 33 ms before to 180 ms (mean 77 +/- 44 ms) after the onset of the QRS complex. The timing of the RV apical electrogram, expressed both as an absolute value and as a percentage of a QRS width, was significantly different when right bundle branch block (BBB) morphology VT (95 +/- 37 ms) and left BBB morphology VT (40 +/- 341) were compared (p less than 0.001). The timing of the RV apical electrogram, expressed as a percentage of the QRS width, was significantly different when VT with different axes were compared in the right BBB VT group (p less than 0.01). A left BBB VT, as compared to a right BBB VT, predicted an RV apical electrogram occurring in the first 35% of the QRS with a sensitivity of 74%, a specificity of 91%, and a positive predictive value of 84%. Right BBB VT with a right and inferior axis were usually associated with the latest occurring RV apical electrogram. A right BBB VT with a right and inferior axis predicted an RV apical electrogram inscribed in the latter half of the QRS with a sensitivity of 65%, a specificity of 84% and a positive predictive value of 80%.(ABSTRACT TRUNCATED AT 250 WORDS)
We sought to investigate the electrocardiographic (ECG) characteristics for guiding catheter ablation in patients with repetitive monomorphic ventricular tachycardia (RMVT) originating from the aortic sinus cusp (ASC).
Repetitive monomorphic ventricular tachycardia can originate from the right ventricular outflow tract (RVOT) and ASC in patients with a left bundle branch block (LBBB) morphology and an inferior axis.
Activation mapping and ECG analysis was performed in 15 patients with RMVT or ventricular premature contractions. The left main coronary artery (LMCA) was cannulated as a marker and for protection during radiofrequency delivery if RMVT originated from the left coronary ASC.
During arrhythmia, the earliest ventricular activation was recorded from the superior septal RVOT in eight patients (group 1) and from the ASC in the remaining seven patients (group 2). The indexes of R-wave duration and R/S-wave amplitude were significantly lower in group 1 than in group 2 (31.8+/-13.5% vs. 58.3+/-12.1% and 14.9+/-9.9% vs. 56.7+/-29.5%, respectively; p < 0.01), despite similar QRS morphology. In five patients from group 2, RMVT originated from the left ASC, with a mean distance of 12.2+/-3.2 mm (range 7.3 to 16.1) below the ostium of the LMCA. In the remaining two patients, the RMVT origin was in the right ASC. All arrhythmias were successfully abolished. None of the patients had recurrence or complications during 9+/-3 months of follow-up.
On the surface ECG, RMVT from the ASC has a QRS morphology similar to that of RVOT arrhythmias. The indexes of R-wave duration and R/S-wave amplitude can be used to differentiate between the two origins. Radiofrequency ablation can be safely performed within the left ASC with a catheter cannulating the LMCA.
Introduction:
The superior right ventricular outflow tract (RVOT) septum and free wall are common locations of origin for outflow tract ventricular tachycardias (VT). We hypothesized that (1) unique ECG morphologies of pace maps from septal and free-wall sites in the superior RVOT could be identified using magnetic electroanatomic mapping for accurate anatomical localization; and (2) this ECG information could help facilitate pace mapping and accurate VT localization.
Methods and results:
In 14 patients with structurally normal hearts who were undergoing ablation for outflow tract VT, a detailed magnetic electroanatomic map of RVOT was constructed in sinus rhythm, then pace mapping was performed from anterior, mid, and posterior sites along the septum and free wall of the superior RVOT. Pace maps were analyzed for ECG morphologies in limb leads and transition patterns in precordial leads. Monophasic R waves in inferior leads for septal sites were taller (1.7 +/- 0.4 mV vs 1.1 +/- 0.3 mV; P < 0.01) and narrower (158 +/- 21 msec vs 168 +/- 15 msec; P < 0.01) compared with free-wall sites; lacked "notching" (28.6% vs 95.2%; P < 0.05); and showed early precordial transition (by lead V4; 78.6% vs 4.8%; P < 0.05). A positive R wave in lead I also distinguished posterior from anterior septal and free-wall sites. Based on QRS morphology in limb leads and precordial transition pattern (early vs late), in a retrospective analysis, a blinded reviewer was able to accurately localize the site of origin of clinical arrhythmia (the successful ablation site on the magnetic electroanatomic map) in 25 of 28 patients (90%) with superior RVOT VT.
Conclusion:
Pace maps in the superior RVOT region manifest site-dependent ECG morphologies that can help in differentiating free-wall from septal locations and posterior from anterior locations. Despite overlap in QRS amplitude and duration, in the majority of patients a combination of ECG features can serve as a useful template in predicting accurately the site of origin of clinical arrhythmias arising from this region.
Identifying the septal versus lateral site of origin of ventricular tachycardia (VT) with a right bundle-branch block (RBBB)-type pattern and an R-S ratio >1 in lead V1 is difficult with the 12-lead ECG, especially in patients with prior apical infarction.
We prospectively evaluated 58 patients with VT. Sixteen patients had apical infarcts (group 1), 29 had nonapical infarcts (group 2), and 13 had no heart disease (group 3). QRS complex onset to activation at the right ventricular apex (stim-RVA) was measured during left ventricular (LV) apical septal and lateral pacing, and 47 RBBB-type VTs (QRS-RVA) were localized to the septal or lateral apex by using entrainment techniques. Pacing and VT site of origin were confirmed by electroanatomic mapping. The stim-RVA time was 59+/-16 ms for septal versus 187+/-24 ms for lateral sites in group 1, P<0.001; 70+/-14 ms for septal versus 169+/-19 ms for lateral sites in group 2, P<0.001; and 42+/-15 ms for septal versus 86+/-16 ms for lateral sites in group 3, P<0.005. The QRS-RVA time was 50+/-13 ms for apical septal VTs versus 178+/-21 ms for lateral VTs in group 1, P<0.001; 71+/-17 ms for apical septal versus 157+/-20 ms for lateral VTs in group 2, P<0.001; and 32+/-12 ms for septal versus 71+/-16 ms for lateral VTs in group 3, P<0.01.
The QRS-RVA differs for the VT site of origin from the LV septal versus lateral apex. These data prove useful in rapidly regionalizing the VT site of origin with a V1 R-S ratio >1, particularly in instances of an apical infarct, where surface ECG distinctions are less identifiable.
The aim of this study was to analyze different anatomic mapping approaches for successful ablation of outflow tract tachycardia with R/S transition in lead V(3).
Idiopathic ventricular tachycardia can originate from different areas in the outflow tract, including the right and left ventricular endocardium, the epicardium, the pulmonary artery, and the aortic sinus of Valsalva. Although electrocardiographic criteria may be helpful in predicting the area of origin, sometimes the focus is complex to determine, especially when QRS transition in precordial leads is in V(3).
We analyzed surface electrocardiograms of 33 successfully ablated patients with outflow tract tachycardia: 20 from the right ventricular outflow tract (RVOT) and 13 from different sites. The R/S transition was determined, and the different anatomic approaches needed for successful catheter ablation were studied.
Overall, R/S transition in lead V(3) was present in 19 (58%) of all patients. In these patients, mapping was started and successfully completed in the RVOT in 11 of 19 (58%) patients. The remaining eight patients with R/S transition in lead V(3) needed five additional anatomic accesses for successful ablation: from the left ventricular outflow tract (n = 3), aortic sinus of Valsalva (n = 2), coronary sinus (n = 1), the epicardium via pericardial puncture (n = 1), and the trunk of the pulmonary artery (n = 1), respectively.
A R/S transition in lead V(3) is common. In patients with outflow tract tachycardia with R/S transition in lead V(3), a stepwise endocardial and epicardial mapping through up to six anatomic approaches can lead to successful radiofrequency catheter ablation.
Ventricular tachycardia (VT) arising from the right ventricular outflow tract (RVOT) in the absence of overt structural heart disease is a common entity. Exclusion of occult structural disease such as arrhythmogenic right ventricular cardiomyopathy is critical as this diagnosis impacts both ablation outcomes and long-term prognosis. VT is most commonly due to triggered activity. Induction of the target arrhythmia in the laboratory is often problematic, and is frequently facilitated by catecholamine infusion. Recent data indicate that high-density three-dimensional activation mapping facilitates identification of target sites for ablation, and that the spatial resolution of pacemapping may be more limited than previously recognized. A standard 12-lead electrocardiogram is useful in providing an initial approximation of the site of origin within the outflow tract, and may contain subtle clues to potentially confounding foci on the left ventricular endocardial or epicardial surface. When sufficient arrhythmia is present to permit mapping, successful ablation can be expected in 90-95% of patients, with a recurrence risk of approximately 5%. In experienced centers, major complications are <or=1% and outcomes should approach those obtained for the common forms of supraventricular tachycardia.
Ventricular arrhythmias (VAs) may arise from the aortic sinuses and have electrocardiographic and electrophysiological characteristics that suggest a left (LCC) or right coronary cusp (RCC) origin. However, VAs that arise near the junction of those two cusps (L-RCC) may have unusual features.
The purpose of this study was to examine the electrocardiographic and electrophysiological characteristics of VAs arising from the L-RCC.
We studied 155 patients with idiopathic VAs with either left or right bundle branch block and an inferior QRS axis morphology and five control subjects undergoing a pacing study.
For 146 of the 155 patients, the origin determined by the successful ablation site was at the L-RCC in five, LCC in 13, RCC in six, non-coronary cusp in two, right ventricular outflow tract in 108, left ventricular outflow tract in five, left ventricular epicardium in four, and pulmonary artery in three. A qrS pattern in leads V1-V3 was observed only in the VAs with an L-RCC origin. The propagation map revealed that the direction of the propagating wave front from the L-RCC origin produced a vector compatible with a q wave and that the anterior activation to the right ventricular outflow tract via the LCC or RCC formed the r wave. Pacing performed at multiple sites in the aortic root in the control subjects demonstrated that only pacing from the L-RCC could reproduce a qrS pattern in leads V1-V3.
This study revealed that a qrS pattern in leads V1-V3 suggests a site of origin at the L-RCC.
The V2 transition ratio: a new electrocardiographic criterion for distinguishing left from right ventricular outflow tract tachycardia origin.
- Betensky B.P.
- Park R.E.
- Marchlinski F.E.
- Hutchinson M.D.
- Garcia F.C.
- Dixit S.
- Callans D.J.
- Cooper J.M.
- Bala R.
- Lin D.
- Riley M.P.
- Gerstenfeld E.P.
A Novel electrocardiographic criterion for differentiating a left from right ventricular outflow tract tachycardia origin: the V2S/V3R index.
- Yoshida N.
- Yamada T.
- Mcelderly T.
- Inden Y.
- Shimano M.
- Murohara T.
- Kumar V.
- Doppalapudi H.
- Plumb V.J.
- Kay G.N.