Origin Of Premature Ventricular Complexes Research Articles

High-resolution repolarization changes preceding short-coupled ectopy in idiopathic ventricular fibrillation, and effects of quinidine

Abstract Background Idiopathic ventricular fibrillation (VF) is linked to early repolarization, increased repolarization heterogeneity, and (short-coupled) premature ventricular complexes (PVCs). Quinidine, an antiarrhythmic drug with class-IA and -III effects, reduces the occurrence of PVCs and VF, but its effects on repolarization have not yet been studied at the whole-heart level in idiopathic-VF patients. Purpose To study dynamic changes in repolarization preceding short-coupled PVCs using noninvasive electrocardiographic imaging (ECGI) in a patient with idiopathic VF, and the antiarrhythmic effects of quinidine. Methods ECGI was performed during sinus rhythm in a 61-year-old male with an ICD (secondary prevention; 2.5 mg nebivolol daily) two days after recurrent idiopathic VF (Fig. A). This was done 1) at baseline, 2 minutes before short-coupled ectopy ("baseline"); 2) at baseline, 10 seconds before the short-coupled PVC ("pre PVC"); and 3) at 2 hours after start of quinidine 200 mg ("on-quinidine"). The ECGI procedure consisted of a 224-electrode body surface potential map and a contrast-enhanced CT scan to obtain torso and heart geometries. After reconstruction of epicardial unipolar electrograms (UEGs), local activation and repolarization times (ATs and RTs) were derived from UEGs by assessing the steepest downslope of the QRS complex and steepest upslope of the T waves, respectively, of 10-second signal-averaged beats. AT and RT duration (first to last AT or RT) were assessed. Results At baseline, QRS duration and QT interval measured 107 ms and 343 ms, respectively, on the standard 12-lead ECG. ECGI-derived epicardial AT duration was 72 ms, and RT histogram span 92 ms. The coupling interval of the PVC that triggered VF in the ICD readout was 340 ms (Fig. A). During 44 minutes of ECGI, 157 short-coupled PVCs from the moderator-band region were recorded (Fig. B; no tachycardia or VF). Just prior to a PVC, epicardial early repolarization at the PVC origin decreased by 26 ms (star in Figs. C-E), and the RT histogram broadened to 109 ms (Fig. E). While on-quinidine, (25 minutes; QRS duration 107 ms, QT interval 419 ms), epicardial repolarization was prolonged (Fig. C/D), also at the site of abnormal impulse formation. Quinidine had increased the epicardial AT duration to 79 ms, and RT histogram span to 133 ms. PVCs were completely suppressed. The patient remained free of sustained arrhythmias while on-quinidine. Conclusion(s) In this case of short-coupled idiopathic VF, epicardial early repolarization shortened momentarily prior to abnormal impulse formation. We found dynamic substrate-trigger characteristics that likely facilitate reentrant excitation. Quinidine prolonged the duration of epicardial activation and repolarization, suppressing the ectopy and VF recurrence.

Zero and near zero fluoroscopy catheter ablation of premature ventricular contractions: a multicentre experience

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation has become an established treatment option for premature ventricular complexes (PVCs). It is well known that the use of fluoroscopy exposes patients and medical staff to potentially harmful stochastic and deterministic effects of ionising radiations. Purpose We sought to analyse procedural outcomes in terms of safety and efficacy using a "zero" or "near zero" X rays approach for treatment of PVCs. Methods The present retrospective, multicentre, observational study included 131 patients having undergone catheter ablation of PVCs using zero or "near zero" (less than 2 minutes) fluoroscopy between 2016 and 2020. Baseline characteristics of the population, acute success and complications derived from the procedure were evaluated, as well as recurrence rate during follow-up. Results Median age was 51.0 years old [38-63], males were 77 (58.8%). Most often cause of ablation were palpitations (90.0%), followed by reduced left ventricular ejection fraction (4.6%) and pre-syncope (14.5%). Among the study population, 26 (19.8%) had a cardiopathy. The median PVC burden before ablation was 15.1% [6%-22.4%]. The most frequent PVC origin was right ventricular outflow tract (n=72; 55.0%) followed by the left ventricle (n=21; 16.0%), LVOT and cusps (n=18; 13.7%) ,aortomitral continuity (n=7; 5.3%). A 3D electro-anatomical mapping system was used in all cases as well as a contact force catheter for mapping and ablation. The mean maximum radiofrequency power applied was 32.9 ± 4.1 W (370 s median time). Median number of applications was 4.5 and mean total procedural time was 117.3 ± 47.5 minutes. Median best prematurity was 31.5 ms. We used isoprenaline in order to induce PVCs in 42% of cases and suppression of PVC was achieved in 127 patients (96.9%). There was only 2 complication (femoral hematoma and arteriovenous fistula conservatively treated). At 12 months, a complete success was documented in 109 patients (83.2%), a reduction in PVC burden was achieved in other 18 patients (13.7%) and a failure was recorded in 4 patients (3.1%). Conclusion The PVC ablation with "zero" or "near-zero" fluoroscopy is a safe procedure with no major complications and good rates of success and recurrence in our multicentre experience.

PO-05-156 DIFFERENTIATING RIGHT VENTRICULAR FROM LEFT VENTRICULAR OUTFLOW TRACT PREMATURE VENTRICULAR COMPLEXES WITH A NOVEL QS PATTERN IN LEAD V1.

Many ECG algorithms for localization of premature ventricular complex (PVC) origin are complex requiring the use of multiple features to achieve high sensitivity and specificity. Simpler diagnostic ECG features may be easier to use and more widely adopted. We hypothesized that a single ECG feature of QS pattern in lead V1 will be specific for PVC localization to the right ventricular outflow tract. All patients at St. Vincent Hospital, Indianapolis from January 01, 2018 to December 31, 2019 that underwent a catheter ablation for outflow tract PVCs were retrospectively evaluated. PVC location was confirmed based on the successful ablation site. For the purpose of this study a QS pattern in V1 was defined if there was no initial R wave and no notching on the downstroke of the Q wave. A total of 63 patients underwent ablation of 70 different PVCs. The median age was 55.6 (interquartile range 47.9, 63.5) years old and included 38 (60.3%) females. Of the 70 PVCs, 47 (67.1%) were right ventricular and 23 (32.9%) were left ventricular outflow tract. A QS pattern was present in 23 (32.8%) of PVCs. Of these 23 PVCs with QS pattern, 22 were right ventricular outflow tract and only 1 localized to the left ventricular outflow tract. The QS pattern in lead V1 had a specificity of 95.6% and sensitivity of 46.8% in identifying a right ventricular outflow tract PVC origin. The novel QS pattern in lead V1 is simple to use and has high specificity for localizing PVC origin to the right ventricular outflow tract.

Usefulness of the synthesized 18-lead ECG in premature ventricular contractions from near the HIS bundle.

Isolated premature ventricular complexes (PVCs) are the most common arrhythmias observed in patients even if without structural heart disease.1 Although most PVCs originate from the right ventricular outflow tract (RVOT), there are some PVCs that originate near the HIS bundle.2 The synthesized 18-lead ECG consists of right-sided thoracic (V3R, V4R, V5R) and dorsal (V7, V8, V9) ECG leads derived from a mathematical calculation of the 12-lead ECG, and the detailed mathematical formula is shown in Figure 1. The synthesized 18-lead ECG has been reported to be effective for PVCs of an RVOT origin, but the rest remains to be elucidated.3 The aim of this study was to investigate the characteristics of the synthesized 18-lead ECG in patients with PVCs originating from near the HIS bundle. The synthesized 18-lead ECGs of 13 consecutive patients who underwent radiofrequency catheter ablation (RFCA) of idiopathic PVCs from near the HIS bundle at the Japan Community Healthcare Organization Osaka Hospital, Osaka General Medical Center, and Nara Prefectural Seiwa Medical Center from January 2018 to December 2020 were included in this retrospective analysis. The origin of the PVCs was identified by a cardiologist using a 3D mapping system (CARTO 3: Biosense Webster Inc or EnSite: Abbott Medical Inc). We analyzed the QRS morphology pattern of the synthesized 18-lead ECG analyzed in those patients. This study was approved by the Ethics Committee of each hospital in accordance with the Declaration of Helsinki. The synthesized 18-lead ECG and ECG characteristics in 13 patients with PVCs from near the HIS bundle are shown in Figure 2 and Table 1. The mean QRS duration of the ECG was 142.5 ± 26.9 ms. In 12 of 13 patients, a left bundle branch block pattern (92.3%) was present, and 11 of 13 patients had inferior axis deviation (84.6%). Regarding the right-sided chest leads of the synthesized 18-lead ECG, in all patients, a QS pattern in lead V5R (100%) was observed, and in 12 of 13 patients, a QS pattern in leads V3R, V4R, and V5R (92.3%) was present. A comparison showed that the synthesized ECGs recorded during sinus rhythm and during PVCs were not consistent, as shown in Table 2. Several studies have shown that identifying PVCs originating from the vicinity of the ventricular septum remains complicated,4 and it is difficult to identify the origin of PVCs originating from near the HIS bundle based on the characteristics of the 12-lead ECG. Noteworthy among our results was that there was a QS pattern in lead V5R in 100.0%. Igarashi et al reported that in the synthesized 18-lead ECG recorded by pace mapping in the outflow tract, a QS pattern in lead V5R was observed in about 80% at the right coronary cusp (RCC), about 20% in the posterior RVOT, and nothing at the other sites.3 Combining the above study3 with our results, a QS pattern in lead V5R might have been specific to PVCs originating from near the HIS bundle and RCC. QRS morphology changes after RFCA are often observed in patients with idiopathic PVCs.5 In such cases, the use of the synthesized 18-lead ECG's right-sided chest leads may assist in the re-mapping process. Regarding the mechanism of the QS pattern in lead V5R, in general the HIS bundle is anatomically closer to the RCC, and electrical conduction may propagate with a vector away from the right-sided chest leads such as lead V5R. Based on the characteristics of the ECG, only case 7 was considered to have a PVC from the HIS bundle. An identification of PVCs originating from near the HIS bundle or from the HIS bundle was attempted based on the characteristics of the synthesized ECG, but was not possible due to an insufficient number of cases. Although a 3D mapping system was used in this study, the distance between the HIS bundle and the ablation site was not measured, and it was considered necessary to include the distance in future studies. A QS pattern recorded in lead V5R of the synthesized 18-lead ECG was characteristic of PVCs originating from near the HIS bundle. This observation might assist in identifying the origin of PVCs during RFCA. H Kida, R Nakanishi, and N Ogasawara participated in the design of the study and coordination and helped draft the manuscript. All authors read and approved the final manuscript. We would like to express our gratitude to Mr. John Martin for his linguistic revision of the manuscript. All authors declare no conflicts of interest associated with this manuscript. This study was approved by the Ethics Committee of Japan Community Healthcare Organization Osaka Hospital, Osaka General Medical Center, and Nara Prefectural Seiwa Medical Center in accordance with the Declaration of Helsinki. Since this study was a retrospective study, we used the opt-out system according to the ethics guidelines on human medical research by the Japanese government.

756 ZERO OR NEAR ZERO FLUOROSCOPY CATHETER ABLATION OF PREMATURE VENTRICULAR CONTRACTIONS: A MULTICENTRE EXPERIENCE

Abstract Background Catheter ablation has become an established treatment option for premature ventricular complexes (PVCs). It is well known that the use of fluoroscopy exposes patients and medical staff to potentially harmful stochastic and deterministic effects of ionising radiations. We sought to analyse procedural outcomes in terms of safety and efficacy using a “zero” or “near zero” X rays approach for treatment of PVCs. Methods The present retrospective, multicentre, observational study included 131 patients having undergone catheter ablation of PVCs using zero or “near zero” (less than 2 minutes) fluoroscopy between 2016 and 2020 in 4 high-volume centres. Baseline characteristics of the population, acute success and complications derived from the procedure were evaluated, as well as recurrence rate during follow-up. Results Median age was 51.0 years old [38-63], males were 77 (58.8%). Most often cause of ablation were palpitations (90.0%), followed by reduced left ventricular ejection fraction (4.6%) and pre-syncope (14.5%). Among the study population, 26 (19.8%) had a cardiopathy. The median PVC burden before ablation was 15.1% [6%-22.4%]. The most frequent PVC origin was right ventricular outflow tract (n=72; 55.0%) followed by the left ventricle (n=21; 16.0%), LVOT and cusps (n=18; 13.7%),aortomitral continuity (n=7; 5.3%). A 3D electro-anatomical mapping system was used in all cases as well as a contact force catheter for mapping and ablation. The mean maximum radiofrequency power applied was 32.9 ± 4.1 W (median time: 370 sec). Median number of applications was 4.5 and mean total procedural time was 117.3 ± 47.5 minutes. Median best prematurity was 31.5 msec. We used isoprenaline in order to induce PVCs in 42% of cases and suppression of PVC was achieved in 127 patients (96.9%). There was only 2 complication (femoral hematoma and arteriovenous fistula conservatively treated). At 12 months, a complete success was documented in 109 patients (83.2%), a reduction in PVC burden was achieved in other 18 patients (13.7%) and a failure was recorded in 4 patients (3.1%). Conclusion The PVC ablation with “zero” or “near-zero” fluoroscopy is a safe procedure with no major complications and good rates of success and recurrence in our multicentre experience.

Cardiac Magnetic Resonance in the Evaluation of Patients With Frequent Premature Ventricular Complexes.

The role of cardiac magnetic resonance (CMR) in the evaluation and management of patients with frequent premature ventricular complexes (PVCs) of unknown etiology remains unclear. This study evaluated the prevalence and prognostic significance of myocardial abnormalities detected with CMR among patients with frequent PVCs and no known structural heart disease. This prospective cohort study included consecutive patients with frequent PVCs and a negative initial diagnostic work-up who underwent CMR with late gadolinium enhancement imaging. The clinical outcome was a composite of mortality, ventricular fibrillation, sustained ventricular tachycardia, or reduction in left ventricular ejection fraction of≥10%. A total of 255 patients were included, of whom 35 (13.7%) had evidence of myocardial abnormality on CMR. Age≥60 years (odds ratio [OR]: 6.96; 95%CI: 1.30-37.18), multifocal PVCs (OR: 10.90; 95%CI: 3.21-36.97), and non-outflow tract left ventricular PVC origin (OR: 3.00; 95%CI: 1.00-8.95) were independently associated with the presence of a myocardial abnormality on CMR. After a median follow-up of 36months, the composite outcome occurred in 15 (5.9%) patients. The presence of a myocardial abnormality on CMR was independently associated with the composite outcome (HR: 4.35; 95%CI: 1.34-14.15; P=0.014). One in 7 patients with frequent PVCs with no known structural heart disease had myocardial abnormality detected on CMR, and these abnormalities were associated with adverse clinical outcomes. These findings highlight the important role of CMR in the evaluation of patients with frequent PVCs.

Ablation of multifocal premature ventricular contractions using automated pace-mapping software

Introduction and ObjectivesAblation of multifocal premature ventricular complexes (PVCs) is challenging. Activation mapping can be performed for the predominant morphology, but may be useless for other less prevalent ones. We aimed to describe the efficacy of an automated pace-mapping software-based ablation strategy for ablating the site of origin of multiple PVC locations. MethodsConsecutive patients referred for ablation of multifocal PVCs were prospectively enrolled. Spontaneous PVC templates were recorded and a detailed pace-mapping map was generated to spot the site of origin of PVCs. ResultsA total of 47 PVCs were targeted in 21 patients (five and 16 patients with three or two PVCs morphologies each, respectively). Detailed pace-mapping comprising 73.5±41.6 different pacing locations was performed (best matching 97.2% [IQR 95.9-98.3%] similar to the clinical PVC). Activation points were acquired if possible, although ablation was only based on pace-mapping in 13 (27.6%) foci. Complete acute procedural success was obtained in 14 (66.7%) patients, while one PVC morphology was deliberately not ablated in five patients (23.8%). After 12.3±9.4 months of follow-up, PVC burden decreased from 24.4±10.4% to 5.6±5.0% (p<0.001). Interestingly, patients with acute procedural failures or with some PVCs deliberately not targeted during the procedure also experienced a significant decrease in PVC burden (30.0±8.9% to 11.9±3.5%, p=0.002). ConclusionQuantitative morphology-matching software can be used to obtain a detailed map identifying the site of origin of each single PVC, and successful ablation can be performed at these sites, even if activation points cannot be obtained due to the paucity of ectopic beats.

Performance and Robustness Testing of a Non-Invasive Mapping System for Ventricular Arrhythmias.

Background: The clinical value of non-invasive mapping system depends on its accuracy under common variations of the inputs. The View Into Ventricular Onset (VIVO) system matches simulated QRS complexes of a patient-specific anatomical model with a 12-lead ECG to estimate the origin of ventricular arrhythmias. We aim to test the performance of the VIVO system and its sensitivity to changes in the anatomical model, time marker placement to demarcate the QRS complex and body position. Methods: Non-invasive activation maps of idiopathic premature ventricular complexes (PVCs) using a patient-specific or generic anatomical model were matched with the location during electrophysiological studies. Activation maps were analyzed before and after systematically changing the time marker placement. Morphologically identical PVCs recorded in supine and sitting position were compared in a subgroup. Results: Non-invasive activation maps of 48 patients (age 51 ± 14 years, 28 female) were analyzed. The origin of the PVCs as determined by VIVO system matched with the clinical localization in 36/48 (75%) patients. Mismatches were more common for PVCs of left than right ventricular origin [11/27 (41%) vs. 1/21 (5%) of cases, p < 0.01]. The first 32 cases were analyzed for robustness testing of the VIVO system. Changing the patient-specific vs. the generic anatomical model reduced the accuracy from 23/32 (72%) to 15/32 (47%), p < 0.05. Time marker placement in the QRS complex (delayed onset or advanced end marker) or in the ST-segment (delaying the QRS complex end marker) resulted in progressive shifts in origins of PVCs. Altered body positions did not change the predicted origin of PVCs in most patients [clinically unchanged 11/15 (73%)]. Conclusion: VIVO activation mapping is sensitive to changes in the anatomical model and time marker placement but less to altered body position.

Diagnostic and prognostic significance of premature ventricular complexes in community and hospital-based participants: A scoping review.

While there are published studies that have examined premature ventricular complexes (PVCs) among patients with and without cardiac disease, there has not been a comprehensive review of the literature examining the diagnostic and prognostic significance of PVCs. This could help guide both community and hospital-based research and clinical practice. Scoping review frameworks by Arksey and O'Malley and the Joanna Briggs Institute (JBI) were used. A systematic search of the literature using four databases (CINAHL, Embase, PubMed, and Web of Science) was conducted. The review was prepared adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Review (PRISMA-ScR). A total of 71 relevant articles were identified, 66 (93%) were observational, and five (7%) were secondary analyses from randomized clinical trials. Three studies (4%) examined the diagnostic importance of PVC origin (left/right ventricle) and QRS morphology in the diagnosis of acute myocardial ischemia (MI). The majority of the studies examined prognostic outcomes including left ventricular dysfunction, heart failure, arrhythmias, ischemic heart diseases, and mortality by PVCs frequency, burden, and QRS morphology. Very few studies have evaluated the diagnostic significance of PVCs and all are decades old. No hospital setting only studies were identified. Community-based longitudinal studies, which make up most of the literature, show that PVCs are associated with structural and coronary heart disease, lethal arrhythmias, atrial fibrillation, stroke, all-cause and cardiac mortality. However, a causal association between PVCs and these outcomes cannot be established due to the purely observational study designs employed.

Catheter ablation of premature ventricular complexes associated with left ventricular false tendons.

Clinical studies have suggested that there is a significant correlation between left ventricular (LV) false tendon and premature ventricular complexes (PVCs). This study aimed to investigate the electrophysiological characteristics and the outcome of radiofrequency catheter ablation (RFCA) for this category of PVCs. From a total of 2284 patients with idiopathic PVCs who underwent catheter ablation at 6 institutions in China, intracardiac echocardiography (ICE) was used during the procedure in 346 cases; 10 patients (2.9%) with PVCs associated with false tendon were retrospectively reviewed and enrolled in the present study. Activation mapping and pace mapping were performed to localize the origin of PVCs. ICE was used in all patients. If the false tendon was directly visualized and identified, we attempted to identify the distinct relationship with the PVC origin. The PVCs were successfully eliminated by ablation in all patients. The target sites were confirmed to be related to false tendon. The origin of PVCs was located at the attachment of the false tendon to the papillary muscle, LV septum, or LV apex. At the target site, high-frequency Purkinje potentials were observed preceding local ventricular activation in 7 patients. LV false tendon can be associated with PVCs, which can be cured by RFCA. An ICE-guided electroanatomical approach should be considered to improve the safety and feasibility of this procedure.

Magnetic resonance imaging in the evaluation of idiopathic frequent premature ventricular complexes with normal ventricular function

Abstract Background The role of cardiac magnetic resonance (CMR) imaging in the diagnostic evaluation of patients with frequent premature ventricular complexes (PVCs) and normal left ventricular ejection fraction (LVEF) remains unclear. Existing data has been predominantly derived from highly selected populations, that may overestimate the true prevalence of abnormal findings on CMR in this patient population. Purpose The aim of this study was 2-fold: 1) to establish the prevalence of CMR imaging abnormalities in a cohort with normal LVEF and high PVC burden; 2) to identify predictors of CMR imaging abnormalities in patients with frequent PVCs and normal LVEF. Methods In this cohort study, 211 patients (age 53.2±19 years; 41% male) with frequent PVCs (≥5%/24 h), of normal LVEF (≥50% by echocardiography) and no known underlying structural heart disease were prospectively enrolled from 2016–2020. Of these, 166 (79%) patients were symptomatic from their PVCs in the form of palpitations, fatigue, chest pain, dizziness, and/or dyspnea. Patients underwent CMR imaging (1.5 Tesla) with a late gadolinium enhancement (LGE) protocol at the time of enrollment for the detection of scarring and/or fibrosis. Results Patients had a median baseline echocardiographic LVEF of 60% (± 5%) with 195 (92%) of patients having a normal native QRS morphology. Median PVC burden of the study cohort was 16% (± 14%). CMR LGE abnormalities were found in 19 (9%) patients including 17 scans with non-ischemic LGE and 2 with ischemic LGE. Age &amp;gt;60 (odds ratio [OR]: 3.20, 95% confidence interval [CI]: 1.20–8.51, p=0.020), male sex (OR: 4.67, 95% CI: 1.61–13.50, p=0.004), history of hypertension (OR: 3.43, 95% CI: 1.31–8.97, p=0.012), native QRS duration (OR: 1.03, 95% CI: 1.00–1.05, p=0.031), and history of non-sustained ventricular tachycardia (OR: 2.81, 95% CI: 1.03–7.68, p=0.044) were significantly associated with the presence of imaging abnormalities on CMR. Dominant PVC origin from the left ventricle had a positive trend (OR: 2.60, 95% CI: 0.99–7.66, p=0.083) to association with CMR imaging abnormalities. On multivariate analysis, male sex (OR: 4.10, 95% CI: 1.40–12.04, p=0.010) and history of hypertension (OR: 2.89, 95% CI: 1.08–7.75, p=0.035) remained significantly associated with the presence of CMR abnormalities. There was no association between CMR imaging abnormalities and the burden of PVCs or the number of PVC morphologies. Conclusion In this cohort, only 9% of patients with apparently idiopathic frequent PVCs and normal LVEF had concealed myocardial abnormalities on CMR imaging. Male sex and history of hypertension were associated with a higher rate of CMR abnormalities. Funding Acknowledgement Type of funding sources: None.

Differentiating the origin of outflow tract premature ventricular complexes using the QRS-right ventricular apex interval

Abstract Background For localization of outflow tract Premature ventricular complexes (PVCs) many ECG criteria have been proposed, however in some cases it is difficult to accurately localize the origin of PVCs using the surface ECG. Objective This study aims to study the relation between QRS-right ventricular apex interval and the origin of the outflow tract PVCs. Patients and Methods The study included 30 patients (27 female, age 37.20 ± 7.87, RVOT origin 18) referred for PVCs ablation and 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) and correlated this interval with origin of outflow tract PVCs as identified by the successful ablation during the procedure. Results Compared to PVCs originating from RVOT, the QRS-RVA interval was significantly longer in PVCs originating from LVOT (67.33±7.56 for LVOT PVCs vs. 37.11±4.34 for RVOT PVCs, p &amp;lt; 0.001). Receiver operating characteristic (ROC) analysis showed that a QRSRVA interval ≥47 ms has a sensitivity, specificity, positive and negative predictive values of 100%, 100%, 100%, 100% respectively, for prediction of an LVOT origin of PVCs Conclusion The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study, A QRS-RVA interval ≥47 ms suggests an LVOT origin of PVCs.

The RV1-V3 transition ratio: A novel electrocardiographic criterion for the differentiation of right versus left outflow tract premature ventricular complexes.

BackgroundSeveral electrocardiographic (ECG) indices have been proposed to predict the origin of premature ventricular complexes (PVCs) with precordial transition in lead V3. However, the accuracy of these algorithms is limited.ObjectivesWe sought to evaluate a new ECG criterion differentiating the origin of outflow tract with precordial transition in lead V3.MethodsWe included in our study patients exhibiting outflow tract PVCs with precordial transition in lead V3 referred for ablation. We analyzed a novel new ECG criterion, RV1-V3 transition ratio, for distinguishing right from left idiopathic outflow tract PVCs with precordial transition in lead V3. The RV1-V3 transition ratio was defined as (RV1+RV2+RV3) PVC / (RV1+RV2+RV3) SR (sinus rhythm).ResultsWe included 58 patients in our study. The ratio was lower for right ventricular outflow tract origins than left ventricular outflow tract (LVOT) origins (median [interquartile range], 0.6953 [0.4818–1.0724] vs 1.5219 [1.1582–2.4313], P < .001). Receiver operating characteristic analysis revealed an area under the curve of 0.856 for the ratio, and a cut-off value of ≥0.9 predicting LVOT origin with 94% sensitivity and 73% specificity. This ratio was superior to any previously proposed ECG criterion for differentiating right from left outflow tract PVCs.ConclusionThe RV1-V3 transition ratio is a simple and accurate novel ECG criterion for distinguishing right from left idiopathic outflow tract PVCs with precordial transition in lead V3.

B-PO01-090 PROSPECTIVE ASSESSMENT OF AN AUTOMATED INTRAPROCEDURAL ECG-BASED SYSTEM FOR LOCALIZING VT EXIT SITES IN PATIENTS WITH STRUCTURAL HEART DISEASE (SHD)

We have previously developed an intraprocedural automatic arrhythmia origin localization (AAOL) system to localize idiopathic ventricular arrhythmia origins onto patient-specific electroanatomic (EAM) surface in real time using a 3-lead ECG. To assess the localization accuracy of ventricular tachycardia (VT) exit and premature ventricular complex (PVC) origin sites in patients with SHD using the AAOL system. In retrospective and prospective cohorts, a total of 42 patients who underwent VT/PVC ablation in the setting of SHD were recruited at two different centers. The AAOL system combines 120-ms QRS integrals of 3 leads (III, V2, V6) with pace mapping to predict VT exit/PVC origin site and projects that site onto the patient-specific electroanatomic surface. VT exit/PVC origin sites were clinically identified by contact mapping. The localization error of the VT exit/PVC origin site was assessed by the distance between the clinically identified site and the estimated site. In the retrospective cohort of 19 patients with SHD, the AAOL system achieved a mean localization accuracy of 6.5±2.6mm for 25 induced VTs. In the prospective cohort with 23 patients, mean localization accuracy was 5.9±2.6mm for 26 VT exit and PVC origin sites (Figure 1). There was no difference in mean localization error in epicardial sites compared to endocardial sites using the AAOL system (6.0 vs. 5.8 mm, P =0.895). Figure 1 shows an example of VT exit site localization. The AAOL system achieved accurate localization of VT exit/PVC origin sites in patients with SHD that is superior to current system, which supports the potential clinical utility.

B-PO01-088 LOCALIZATION OF OUTFLOW TRACT PREMATURE VENTRICULAR BEATS OR VENTRICULAR TACHYCARDIA IN SURFACE ELECTROCARDIOGRAMS USING A CONVOLUTIONAL NEURAL NETWORK

ECG based algorithms for localization of outflow tract (OT) premature ventricular complexes (PVCs) have variable sensitivity and specificity. Machine learning may identify visually imperceptible ECG changes and augment predictive accuracy, especially in early disease stages. To compare a Convolutional Neural Network (CNN) with manual PVC localization of left vs. right ventricular (RV vs. LV) OT PVC. All patients with successful ablation of RV-LV OT from 1/2013-1/2020 were included if they had at least one standard 12-lead ECG recorded with a clinical PVC before ablation. PVC origin was defined by the site of successful ablation excluding LV summit, aorto-mitral continuity and para-hisian PVCs. Success was defined as absence of the targeted PVC for the 24 hr post procedure monitoring. We compared CNN performance to 3 OT PVC localization algorithms (Table 1). Patient-level ECG data were split into Training, Validation and Test Datasets in a ratio of approximately 7:1:2. Results are reported as averaged across 10 random splits of the data and model initializations for robustness. 308 ECGs (86 RVOT, 43 LVOT, 179 sinus) from 75 patients were used for CNN development. CNN classified RVOT PVC with similar sensitivity to algorithms but with higher specificity (Table 2). For LVOT PVC, CNN specificity was higher, and sensitivity was higher than all but one, of the manual algorithms. The CNN area under the receiver operating characteristic curve for LVOT and RVOT were 0.929 and 0.914, respectively. A CNN can achieve higher specificity at similar or higher sensitivity compared to most published algorithms to differentiate right from left OT PVCs.

Zero fluoroscopy PVC ablation

Abstract Funding Acknowledgements Type of funding sources: None. Premature ventricular complex(PVC) catheter ablation is required in a wide spectrum of the population.Ionizing radiation exposure in this procedure carries health risks,especially in young patients. In this prospective observational study we included 18 patients,submitted to PVC ablation without fluoroscopy between October 2018 and December 2020.Baseline characteristics of the population,acute success and complications derived from the procedure were evaluated,as well as recurrence rate during follow-up. Median age was 49.5 years. Most often cause of ablation were palpitations(77.8%),followed by reduced LVEF(16.7%) and dyspnoea(5.6%).33.3% had a cardiopathy,the most common was tachycardiomyopathy(66.7%).PVC burden pre-ablation was 25 ± 12.6%.The most frequent PVC origin was RVOT(66.7%)followed by LVOT(22.2%),mitral annulus(5.6%) and papillary muscles(5.6%). We used a 3D electroanatomical navigation system in all cases,intracardiac echocardiography in 88.9% and a contact force catheter for mapping(61%) and ablation(88.9%).The mean maximum radiofrequency power applied was 35 ± 5.7W(236.5s median time).Median number of applications was 5.5 and mean total procedural time was 198.6 ± 67.5 minutes.Median best prematurity was 28ms.We used isoprenaline in order to induce PVC in 77.8% of cases and suppression of PVC was achieved in 88.9%.There was only one complication(pericardial effusion without the need for pericardiocentesis).Median follow-up of 5 months,17.6% of recurrences(&amp;lt;80% reduction of PVC burden at 3 months),all them(3) from RVOT. In conclusion, the PVC ablation without fluoroscopy is a safe procedure with no major complications and good rates of success and recurrence in our experience. Baseline characteristics of the patientsMale6(33.3%)Female12(66.7%)Median age-yr.(range)49.5 (23-71)HTA6(33.3%)DM2(11.1%)Dyslipidemia3(16.7%)Smoking6(33.3%)LVEF median-(%)56.5%Treatment pre-ablationBeta blockers11(61.1%)No treatment6(33.3%)BB + flecainide/propafenone1(5.6%)1st column: Characteristics /2nd column: Patients included (N = 18) Abstract Figure 1

New composite index has superior sensitivity in prediction of PVC-induced tachycardiomyopathy in patients with intermediate arrhythmic burden

Aims – Frequent premature ventricular complexes (PVCs) may induce/aggravate LV systolic dysfunction (LVD) by tachy(dyssynchrono)cardiomyopathy (tCMP) in patients with/without previous structural heart disease. High arrhythmic burden (i.e. &gt;26%) is the main predictor of tCMP development in patients with previously normal LV function. However, its predictive power is reduced once the arrhythmic burden is below 26%, with considerable overlap between patients at risk for tCMP and those who will maintain normal LV function. We sought to evaluate the predictive power of a composite index that includes PVC burden, PVC duration and PVC coupling interval. Methods – 61 patients referred for radiofrequency ablation (RFA), with frequent PVCs refractory to at least one antiarrhythmic drug (AAD), symptomatic and/or with LV systolic dysfunction (LVEF &lt; 50%) were retrospectively studied. Patients with structural lesions on transthoracic echocardiography (TTE) and/or cardiac magnetic resonance imaging (c-MRI), with sustained ventricular tachycardia/supraventricular tachycardia or severe valvular disease were excluded. A composite parameter dependent on PVC burden, PVC duration and PVC coupling interval was defi ned. Results – Mean PVC burden was 25.80% ± 11.64 (35% ± 8.16 in tCMP subgroup). Chronic PVC suppression was achieved in 89.6% of patients with a mean of 1.44 ± 0.7 procedures with 86.4% of patients requiring one procedure. Septal right ventricular outfl ow tract (RVOT) was the most frequent PVC origin (36.1%). Mean left ventricular ejection fraction (LVEF) in the tCMP group (7 patients) was 38% ± 5.26 which increased 1 month after RF ablation to 54.6% ± 3.64 (87.35% of recovered LVEF), at 3 months to 56% ± 2.23 and at 6 months 57% ± 2.73. LVEF recovery was also present in non-tCMP subgroup, yet statistically insignifi cant. There was no procedure-related mortality. Retrograde ventriculo-atrial (VA) conduction, male gender, non-sustained VT (NSVT), a higher BMI and a higher PVC burden were associated with tCMP development. ROC curve analysis appears to demonstrate higher sensitivity of tCMP prediction by the composite index in comparison to PVC burden in patients with 16.93-25.93% PVCs (i.e. below the formerly described tCMP PVC% cut-off). Conclusions – In patients with a PVC burden lower than the previously described cut offs (i.e. with ~17-25% PVCs) PVC mediated systolic dysfunction seems to be predicted with higher sensitivity by a composite index accounting for PVC burden, PVC duration and PVC coupling interval.

Prediction of premature ventricular complex origins using artificial intelligence–enabled algorithms

BackgroundCatheter ablation is a standard therapy for frequent premature ventricular complex (PVCs). Predicting their origin from a 12-lead electrocardiogram (ECG) is crucial but it requires specialized knowledge and experience.ObjectiveThe objective of the present study was to develop and evaluate machine learning algorithms that predicted PVC origins from an ECG.MethodsWe developed the algorithms utilizing a support vector machine (SVM) and a convolutional neural network (CNN). The training, validating, and testing data consisted of 116 PVCs from 111 patients who underwent catheter ablation. The ECG signals were labeled with the PVC origin, which was confirmed using a 3-dimensional electroanatomical mapping system. We classified the origins into 4 groups: right or left, outflow tract, or other sites. We trained and evaluated the model performance. The testing datasets were also evaluated by board-certified electrophysiologists and an existing classification algorithm. We also developed binary classification models that predicted whether the origin was on the right or left side of the heart.ResultsThe weighted accuracies of the 4-class classification were as follows: SVM 0.85, CNN 0.80, electrophysiologists 0.73, and existing algorithm 0.86. The precision, recall, and F1 in the machine learning models marked better than physicians and comparable to the existing algorithm. The SVM model scored among the best accuracy in the binary classification (the accuracies were 0.94, 0.87, 0.79, and 0.90, respectively).ConclusionArtificial intelligence–enabled algorithms that predict the origin of PVCs achieved superior accuracy compared to the electrophysiologists and comparable accuracy to the existing algorithm.

Abstract 12935: Predictors of Long-term Success After Catheter Ablation of Premature Ventricular Complexes

Introduction: Some patients(pts) have late recurrence after acutely successful radiofrequency catheter ablation(RFCA) of premature ventricular complexes (PVC). Hypothesis: The aim of this study was to evaluate predictors of long term success following acutely successful PVC ablation. Methods: From 2016-19, we identified consecutive pts at our institution with frequent PVCs undergoing RFCA and reviewed procedural data and medical records. Earliest local activation on the intracardiac bipolar and unipolar electrogram was measured using digital calipers. Acute success was defined as elimination of targeted PVC for at least 30 mins after RFCA. Long term success was defined as absence of PVC on 12 lead ECG during all follow up (f/u) visits and PVC burden reduction &gt;80% or PVC burden &lt;5% on f/u monitoring at 1 year. Results: Among 241 pts, 161 (66.8%) pts had long term success with mean f/u of 17.6±5.8 months.In univariate analysis, diabetes mellitus and alcohol use were associated with PVC recurrence while age, female sex, acute success, ablation time, right ventricular PVC origin, single PVC morphology (sPVC), and earliest bipolar activation&gt;24msec pre-QRS were associated with long-term success. In multivariate analysis, female sex, sPVC and earliest activation &gt;24 msec preQRS were independent predictors of long term success at 1 year. The positive predictive value of earliest bipolar onset preQRS of PVC&gt;24msec for long term success was 0.77(P&lt;0.001). Negative predictive value of earliest onset preQRS &lt;15msec for long term success was 0.86(P=0.003), suggesting that ablation when the local bipolar electrogram preceded the QRS by &lt;15ms was unlikely to result in long term success. Conclusions: Female gender, sPVC, and earliest onset of bipolar electrogram preQRS&gt;24msec were predictors of long term success in patients with PVC undergoing RFCA. If local onset is &lt;15ms, RF ablation is not worthwhile. The reason for improved outcome in females requires further study.

Utility of Circadian Variability Patterns in Differentiating Origins of Premature Ventricular Complexes.

Background Premature ventricular complexes (PVCs) exhibit circadian fluctuation. We determine if PVCs of different origin exhibit specific circadian patterns. Methods We analyzed Holter recordings from patients with monomorphic PVCs who underwent catheter ablation. PVC circadian patterns were classified as fast-heart rate- (HR-) dependent (F-PVC), slow-HR-dependent (S-PVC), or HR-independent (I-PVC). PVC origins were determined intraprocedurally. Results In a retrospective cohort of 407 patients, F-PVC and S-PVC typically exhibited diurnal and nocturnal predominance, respectively. Despite decreased circadian fluctuation, I-PVC generally had heavier nocturnal than diurnal burden. PVCs of left anterior fascicle origin were predominantly S-PVC, while those of posterior hemibranch origin were mostly F-PVC. PVCs originating from the aortic sinus of Valsalva (ASV) were predominantly I-PVC, while most PVCs arising from the left ventricular outflow tract (LVOT) were F-PVC. Using a diurnal/nocturnal PVC burden ratio of 0.92 as the cutoff value to distinguish LVOT from ASV origin achieved 97% sensitivity and, as further verification, an accuracy of 89% (16/18) in a prospective cohort of patients with PVCs originating from either ASV or LVOT. In contrast, PVCs originating from right ventricles, such as right ventricular outflow tract, did not show distinct circadian patterns. Conclusions The circadian patterns exhibit origin specificity for PVCs arising from left ventricles. An analysis of Holter monitoring provides useful information on PVC localization in ablation procedure planning.