Ablation Of Premature Ventricular Contractions Research Articles

Successful ablation of premature ventricular contractions originating from the posterior-superior process of the left ventricle approaching from the right atrium in a 13-year-old male.

This is a case of a 13-year-old male with frequent premature ventricular contractions with QRS configurations of the left superior axis and left bundle branch block, which originated from the posterior-superior process of the left ventricle. Premature ventricular contractions were successfully eliminated by delivering radiofrequency energy to the inferior wall of the right atrium without causing either junctional rhythm or atrioventricular block. Ventricular arrhythmias originating from this site have been sporadically reported in adults; however, this is the first report in a child.

Anatomically Based Ablation of Left Ventricular Summit Premature Ventricular Complexes Guided by Intracardiac Echocardiography.

Catheter ablation of premature ventricular contractions (PVCs) arising from the left ventricular summit (LVS) presents technical challenges due to the regional anatomy and frequent intramural site of origin (SOO). Intracardiac echocardiography (ICE) and the CARTOSOUND® (Biosense Webster, Diamond Bar, CA, USA) module allow the operator to directly reconstruct and visualize the dimensions and orientation of the LVS live and present it in relation to neighboring structures. We retrospectively reviewed consecutive cases between January 2021 and December 2022 of patients undergoing PVC ablation for a presumed LVS origin. The LVS was reconstructed by creating a three-dimensional representation of the left ventricular septum, using two-dimensional ICE sections. The earliest site in each chamber was tagged on the reconstructed LVS, and the presumed SOO was localized using a geometrical center point from all sites. Ablation was first delivered to the earliest site, except when the presence of coronary branches precluded radiofrequency delivery within the great cardiac vein. Of 20 patients (8 women, 62.4 ± 7.1 years old) with a presumed LVS origin, 12 had PVC recurrence within the monitoring period after the initial ablation for 192.5 ± 37.2 s at the earliest site. Among them, earliest activation was seen at the sinus of Valsalva (SoV), coronary venous system (CVS), and left ventricular endocardium (LVE) in four, six, and two patients, respectively. Using the reconstructed LVS, the anatomically closest site to the SOO was identified in the SoV, CVS, and LVE in four, two, and six cases, respectively. Throughout the study period (14.5 months; range, 9.3-19.7 months), 17 patients (85%) had complete elimination of PVCs as evaluated by 24-h event monitors at the 12-month visit. In 50% of cases, among patients in whom ablation at the earliest signal was unsuccessful, the site of successful ablation did not correlate with the second earliest signal or had no identifiable signal during initial activation mapping. The reconstructed LVS not only guided activation mapping but also identified sites proximal to the center point that had either a late activation signal, a low-amplitude signal, or no signal at all.

Zero fluoroscopy catheter ablation of premature ventricular contractions: a multicenter experience

Zero fluoroscopy catheter ablation of premature ventricular contractions: a multicenter experience

Electrophysiological Characteristics and Ablation Outcomes in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia.

Catheter ablation of premature ventricular contractions (PVCs) that trigger polymorphic ventricular tachycardia (PVT) or ventricular fibrillation has been reported as a novel therapy to reduce the syncope events in patients with catecholaminergic PVT, whereas the long-term ablation outcome and its value in improving exercise-induced ventricular arrhythmias remain unclear. Fourteen consecutive selected patients with catecholaminergic PVT (mean±SD age, 16±6 years; 43% male patients) treated with maximum β-blockers with no possibility of adding flecainide were prospectively enrolled for catheter ablation. The primary end point was syncope recurrence, and the secondary end point was the reduction of the ventricular arrhythmia score during exercise testing. Twenty-six PVT/ventricular fibrillation-triggering PVCs were identified for ablation. The trigger beats arose from the left ventricle in 50% of the cases and from both ventricles in 36% of the cases. Purkinje potentials were observed at 27% of the targets. After a mean follow-up of 49 months after ablation, 8 (57%) patients were free from syncope recurrence. Ablation of trigger beat significantly reduced the syncope frequency (mean±SD, 4.3±1.6 to 0.5±0.8 events per year; P<0.001) and improved the ventricular arrhythmia scores at the 3-month (5 [range, 3-6] to 1.5 [range, 0-5]; P=0.002) and 12-month (5 [range, 3-6] to 2 [range, 0-5]; P=0.014) follow-ups. The induction of nontriggering PVCs postablation was closely associated with syncope recurrence (hazard ratio, 6.8 [95% CI, 1.3-35.5]; P=0.026). Catheter ablation of PVT/ventricular fibrillation-triggering PVCs in patients with catecholaminergic PVT who cannot receive flecainide treatment seems to be a safe and feasible adjunctive treatment that may reduce the syncope burden and improve exercise-related ventricular arrhythmias. Induction of nontriggering PVCs after ablation is associated with a higher risk of syncope recurrence.

Benefit of the Combined use of Three-Dimension Anatomical Mapping and Intracardiac Echocardiography in Catheter Ablation of Premature Ventricular Contraction Coming from the Moderator Band of the Right Ventricle: A Case Report

Introduction: The moderator band connects the anterior papillary muscle of the tricuspid valve with the free wall of the right ventricle. It is associated with sudden cardiac death risk. Radiofrequency ablation is the treatment of choice for this type of arrhythmias. Description: An 18-year-old patient with no structural heart disease, 17% of premature ventricular contraction in holter. An ablation using three-dimension electroanatomical system was performed with recurrence after 48 hours. Due to the absence of response to antiarrhythmic drugs a new catheter ablation was performed combining three-dimension electroanatomical system and intracardiac echocardiography. The arrhythmia was interrupted 6 seconds after the start of the application. During follow-up, 48 hours Holter monitoring demonstrated no ventricular arrhythmias at 3, 6, 12, and 18 months. Conclusion: It is very important to combine the use of three-dimension anatomical mapping system and intracardiac echocardiogram while performing premature ventricular contraction ablation originated in the moderator band in order to obtain better outcomes in this type of arrhythmias, associated with risk of sudden cardiac death.

Duration of left and right atrial activation wavefront assessed non-invasively is significantly higher in patients with atrial fibrillation than in controls

Abstract Introduction Ablation strategies in atrial fibrillation (AF) are currently a "one-size- fits- all" type of approach. Pulmonary vein isolation as the standard of care is not perfect, especially in the persistent forms, but none of the alternatives has shown better results. The dichotomic paroxysmal versus persistent AF classification in no longer acceptable. Characterization of the atrial substrate before ablation is needed. Electrocardiographic imaging (ECGI) is capable of non-invasively assess atrial activation in a single beat and in a panoramic fashion. The aim of this study was to evaluate the feasibility and accuracy of ECGI to assess the activation speed and identify possible targets for ablation. Methods We studied 18 consecutive patients, 9 referred for ablation of paroxysmal AF and 9 without AF, referred for ablation of premature ventricular contractions (PVCs), that had an ECGI performed before ablation. No patient had structural heart disease and all patients had normal electrocardiographic evaluation in sinus rhythm (SR). The ECGI was performed in SR with the AMYCARD 01 system, based on body surface electrocardiograms of a maximum of 224 electrodes and computed tomography imaging data. Total duration of atrial activation, left atrial (LA), and right atrial (RA) activation duration, and presence of lines of conduction block (LOB) defined as the presence of a jump in the local activation time of 50 ms or more between contiguous points, were assessed. The results were compared in patients with and without AF. Results The results are depicted in the Table. Patients with AF were older. Total atrial activation duration, LA, and RA activation duration were longer in patients with AF and there was a trend towards a higher prevalence of LOB in the LA in patients with AF (Figure). Discussion &amp; Conclusion Total atrial activation duration as well as LA and RA activation duration assessed with the ECGI were significantly prolonged in patients with AF. Presence of LOB in the LA showed a trend towards a higher prevalence in AF patients. These pilot study has proved that this technology is accurate in identifying a pathological substrate in AF patients. We intend to use ECGI in a subsequent study that will include patients with AF both in paroxysmal and persistent forms, in order to identify markers of disease as well as possible targets to perform a customized AF ablation.Comparison between AF and control groupsECGI showing local activation times

Bilateral Cardiac Sympathetic Denervation for Refractory Multifocal Premature Ventricular Contractions in Patients With Nonischemic Cardiomyopathy

BackgroundBilateral cardiac sympathetic denervation (BCSD) for refractory life-threatening ventricular arrhythmias is a neuromodulatory intervention targeting sympathetically driven focal or re-entrant ventricular arrhythmias. ObjectivesThis study sought to provide a more complete and successful option for intervention in patients in whom premature ventricular contraction (PVC) ablation is not feasible or has been unsuccessful. MethodsA total of 43 patients with >5% PVC burden and concomitant nonischemic cardiomyopathy (NICM) who previously failed medical and ablation therapies were referred for BCSD. All patients underwent bilateral video-assisted thoracoscopic surgical approach with T1-T4 sympathectomy. Primary effectiveness endpoints were postprocedural PVC burden resolution, improvement in left ventricular ejection fraction (LVEF), and cessation of antiarrhythmic drugs (AADs). Safety endpoints included peri- and postprocedural complications. Outcomes were assessed over a 1-year follow-up period. ResultsAmong the 43 patients who underwent BCSD, the mean age was 52.3 ± 14.7 years, 69.8% of whom were male patients. Presenting mean LVEF was 38.7% ± 7.8%, and PVC burden was 23.7% ± 9.9%. There were significant reductions in PVC burden postprocedurally (1.3% ± 1.1% post-BCSD, compared with 23.7% ± 9.9% pre-BCSD, P < 0.001) and improvements in LVEF (46.3% ± 9.5% post-BCSD, compared with 38.7% ± 7.8% pre-BCSD, P < 0.001). The rate of ICD therapies decreased from 81.4% (n = 35) to 11.6% (n = 5) (P < 0.001), leading to a significant reduction in use of AADs (100.0% to 11.6%, P < 0.001) and improvement in mean NYHA functional class (2.5 ± 0.5 to 1.4 ± 0.2, P < 0.001). Major intraoperative complications were seen in 4.7% of patients (hemothorax and chylothorax). Of the patients, 81.4% (n = 35) experienced no mortality or major complications over a 1-year follow-up period, with the remaining still within their first year postprocedure. ConclusionsBCSD is effective for the management of refractory PVCs and ventricular tachycardia who have failed previous ablation therapy.

Abstract 17188: Electrocardiographic Algorithms for Localization Ventricular Ectopy From the Ventricular Outflow Tracts Demonstrate Poor Accuracy and Agreement

Background: Premature ventricular contractions (PVCs) and ventricular tachycardia (VT) commonly arise from the outflow tracts of the left and right ventricles and can be treated with catheter ablation when symptomatic or associated with cardiomyopathy. Accurate localization of these ectopic sources aids procedural planning. Several different electrocardiographic (ECG) algorithms have been published, but their relative performance has not been assessed. Objective: Compare the accuracy and agreement of three ECG algorithms for PVC localization. Methods: ECGs from patients who underwent catheter ablation for PVCs or VT originating the outflow tract region were analyzed using three published PVC localization algorithms. The predictions from these algorithms were then compared to the site of successful catheter ablation (right ventricular outflow tract [RVOT], left ventricular outflow tract [LVOT], or epicardium). The accuracy and agreement of the three algorithms were compared. Results: A total of 43 patients were evaluated and ectopy was suppressed via ablation from a single chamber in 37 (86%) of patients. VT/PVCs originated from the RVOT (N=10), LVOT (N=26), and epicardium (N=1). The three studied algorithms demonstrated accuracy rates of 46-70%. The algorithms disagreed on the predicted ectopy location for 19 (51%) patients. When all algorithms agreed (N=18), the prediction was accurate for only 11 patients (61%). Conclusion: Rules-based ECG algorithms demonstrate poor performance and use of different published algorithms frequently result in disparate results. More accurate and consistent methods incorporating individualized electroanatomic variation may improve accuracy and periprocedural management for PVC and VT ablation.

Abstract 16045: Fluoroless Arterial Access and Closure for VT Ablation: Feasibility and Safety of an Ultrasound Guided Landmark Approach

Introduction: Ultrasound (US) guided access has become the gold standard of care for central access cannulation. The FAUST1 trial demonstrated that routine real-time US guidance was equivalent to fluoroscopic guidance but improved common femoral artery (CFA) access success and reduced complications in patients with high CFA bifurcations. The utilization of non radiation imaging modalities over the past decade has resulted in significantly reduced radiation exposure and orthopedic problems associated with prolonged electrophysiology procedures2. Hypothesis: Why do many operators still use fluoroscopy and arteriograms in addition to ultrasound guided access? Methods: A prospective single center multi-operator study was performed on patients undergoing premature ventricular contractions (PVC) or Ventricular Tachycardia (VT) ablation with arterial access. CFA access was obtained using a US guided landmark identification protocol. US probe is utilized in short and long access to identify upper and lower borders of the femoral head in relation to the CFA bifurcation. CFA access is then obtained with a modified Seldinger approach within femoral head landmarks. After arterial sheath insertion, the artery is again evaluated for closure appropriateness, assessed by absence of arterial calcifications within 5mm of arrteriotomy or stenosis &lt;5mm in diameter. Results: 20 consecutive patients undergoing PVC or PVT ablation were included. All patients underwent US only guided access to the right common femoral artery. All patients underwent successful closure with a hemostasis device. There were no vascular complications. Conclusions: Real-time US only guided CFA access is feasible and safe. Appropriate utilization of US is sufficient to avoid intravenous contrast and radiation exposure without increased complication rate.

Successful Supravalvular Radiofrequency Catheter Ablation of Premature Ventricular Contractions Originating From the Left Ventricular Summit

Successful Supravalvular Radiofrequency Catheter Ablation of Premature Ventricular Contractions Originating From the Left Ventricular Summit

Outcomes of catheter ablation in high-risk patients with Brugada syndrome refusing an implantable cardioverter defibrillator implantation.

The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population.

The comparison between the novel technique and conventional method in the catheter ablation of premature ventricular contractions originating from the free wall of tricuspid annulus.

This study aimed to assess the safety and effectiveness of a novel technique for catheter ablation in patients with premature ventricular contraction (PVC) from the free wall of tricuspid annulus (TV). We hypothesized that the novel technique is more efficacious than the traditional approach. We retrospectively investigated 59 consecutive patients with PVC originating from the free wall of TV between January 2013 and November 2021. The patients were divided into two groups: the reversed S-curve technique group (RST, n = 26) and the reversed C-curve technique group (RCT, n = 33). The RST under the support of a steerable sheath was used in RST group, while the RCT under the support of a nonsteerable sheath was used in the RCT group. Systematic mapping and radiofrequency ablation were preferentially performed under the valve in all patients. Compared to the RCT group, total procedural time and fluoroscopic exposure time were significantly shorter in RST group. Two patients experienced cardiac tamponade in the RCT group, while no complications were observed in RST group (p = .498). The success rate was significantly higher in RST group compared to RCT group (81.9% vs. 100%, p = .029). Three patients in RCT group failed to ablate during the operation but were successfully ablated using the novel method. During regular follow-up, no patients in the RST group had a recurrence, while three patients in the RCT group did (p = .274). It suggests that the reserved S-curve technique, supported by a steerable sheath, is a feasible and effective method for ablating PVC originating from the free wall of TV.

Unipolar and bipolar electrograms to predict successful ablation site of premature ventricular contractions originating from the free wall of the tricuspid annulus.

This study aimed to identify the characteristics of unipolar and bipolar electrogram (UniEGM and BiEGM) in guiding successful ablation of premature ventricular contractions (PVCs) originating from the free wall of the ventricular aspect of the tricuspid annulus (TA). We hypothesized that the negative concordance pattern (NCP) on the onset of UniEGM and BiEGM, together with the least value of the difference between the earliest BiEGM and UniEGM dV/dTmax, might improve the accuracy of conventional mapping. Thirty consecutive patients who underwent successful catheter ablation from February 2018 to July 2021 were retrospectively analyzed. The BiEGM and UniEGM for successful ablation sites were compared with those for non-successful ablation sites. Among the 30 patients, 30 successful and 26 nonsuccessful ablation sites were compared. The earliest activation time of the BiEGM (BiEGMoneset-QRS) was 25 ± 6 ms for the successful ablation sites and 21 ± 6 ms for the nonsuccessful ablation sites (p = .47). The value of the difference in the earliest BiEGM and UniEGM dV/dTmax differed between successful and nonsuccessful ablation sites (6.4 ± 3.6 ms vs. 10.4 ± 6.8 ms). NCP was observed at 90.0% and 42.3% of the successful and nonsuccessful ablation sites, respectively. Alignment of NCP and BiEGMonset-UniEGM ≤6 ms was applied as the mapping criterion for successful PVC suppression (73.1% sensitivity and 87.7% specificity). The area under the receiver-operating characteristic curve for this cutoff was 0.85. Mapping based on an NCP at the onset of the BiEGM and UniEGM and the least difference value of the earliest BiEGM and UniEGM dV/dTmax had an excellent predictive value for successful ablation. These strategies may reduce the number of radiofrequency catheter ablation (RFCA) applications for free-wall tricuspid annular PVCs.

Complicated catheter ablation of premature ventricular contractions from the left sinus of Valsalva in a young female. Case presentation.

Idiopathic premature ventricular complexes (PVCs) are usually benign and are often treated conservatively. Data regarding radiofrequency catheter ablation (RFA) of PVCs from the aortic sinus of Valsalva are spare. Furthermore, there are limited data regarding complications and their solutions during RFA of PVCs from the aortic sinus of Valsalva. Here we describe a clinical case of symptomatic PVCs in a 27yrold young woman with reduced exercise tolerance and dyspnea. The patient had taken anti-arrhythmic group Ic, II, and III drugs with no significant effect. Successful catheter ablation of PVCs from the left sinus of Valsalva was complicated by acute occlusion of the left main coronary artery (LCA) followed by polymorphic ventricular tachycardia and ventricular fibrillation. Cardioversion and intravenous antiarrhythmic administration restored the sinus rhythm. The LCA was stented with a bioresorbable Magmaris stent with the support of extracorporeal membrane oxygenation that was required due to severe hypotension and ineffectiveness of vasopressors. After the procedure, a favorable angiographic effect was noted. The result of stenting was monitored with IVUS intravascular navigation. The patient was discharged in a satisfactory condition on the 10th day after the procedure. Special attention should be applied to prevent complications and to careful patient selection for RFA in the left sinus of Valsalva, and care must be taken to avoid injury to the LCA. Timely and correct procedures can result in patient survival even after acute LCA injury and occlusion.

Use of Ripple mapping to enhance localization and ablation of outflow tract premature ventricular contractions.

Accurate localization of septal outflow tract premature ventricular contractions (PVCs) is often difficult due to frequent mid-myocardial or protected origin. Compared with traditional activation mapping, CARTO Ripple mapping provides visualization of all captured electrogram data without assignment of a specific local activation time and thus may enhance PVC localization. Electroanatomic maps for consecutive catheter ablation procedures for septal outflow tract PVCs (July 2018-December 2020) were analyzed. For each PVC, we identified the earliest local activation point (EA), defined by the point of maximal -dV/dt in a simultaneously recorded unipolar electrogram, and the earliest Ripple signal (ERS), defined as the earliest point at which three grouped simultaneous Ripple bars appeared in late diastole. Immediate success was defined as full suppression of the clinical PVC. Fifty-seven unique PVCs in 55 procedures were included. When ERS and EA were in the same chamber (RV, LV, or CS), the odds ratio for the successful procedure was 13.1 (95% confidence interval [CI] 2.2-79.9, p = .005). Discordance between sites was associated with a higher likelihood of needing multi-site ablation (odds ratio [OR] 7.9 [1.4-4.6; p = .020]). Median EA-ERS distance in successful versus unsuccessful cases was 4.6 mm (interquartile range 2.9-8.5) versus 12.5 mm (7.8-18.5); (p = .020). Greater EA-ERS concordance was associated with higher odds of single-site PVC suppression and successful septal outflow tract PVC ablation. Visualization of complex signals via automated Ripple mapping may offer rapid localization information complementary to local activation mapping for PVCs of mid-myocardial origin.

Impact of pacing output and cycle length on QRS morphology in ablation of premature ventricular contractions (PACE-MAP-trial)

Abstract Funding Acknowledgements Type of funding sources: None. Background Pace mapping is an established technique to localize the origin of premature ventricular contractions (PVC). The QRS morphology induced by endocardial pacing is compared with a previously recorded template of the target arrhythmia. Based upon historic in-vitro models pacing at the arrhythmia’s coupling interval (CI) and stimulation threshold has become the gold standard in pace mapping. Purpose There is a paucity of data supporting pacing at the CI and stimulation threshold as the gold standard for pace mapping. In this prospective study, we sought to assess systematically the impact of variations of pacing output and cycle length on the resulting QRS morphology during pace mapping in the context of PVC ablation. Methods All patients undergoing ablation of idiopathic PVC were prospectively enrolled in this study. Pace mapping was performed using four different parameter settings: (1) A predefined fixed burst at maximum output (10V/2ms), (2) fixed burst at stimulation threshold, (3) coupling interval at maximum output and (4) coupling interval at stimulation threshold. Pacing cycle length (PCL) of the fixed burst was defined as follows: For a CI≤450ms = PCL of CI+100ms and for a CI≥450 = PCL of CI-100ms. Using an automated waveform comparison algorithm (Bard® LabSystem™ PRO software; Boston Scientific, MA, USA), the resulting QRS complexes were matched with the clinical PVC, and with the gold standard. For every parameter setting the mean of the matching percentage of three QRS complexes entered the analysis. Results We report data of the first 47 consecutive patients (57±18 years, 64% male) enrolled in this ongoing study between May 2021 and September 2022. The pacing protocols were performed at 75 different sites: 6/75 epicardially via great cardiac vein, 38/75 in the RVOT, 23/75 in LVOT and 8/75 in the left ventricular cavity. When comparing the QRS morphologies resulting from the four different pace mapping settings with the clinical PVC, the univariate analysis revealed no difference between groups (p=0.9). Furthermore, there was no difference comparing the paced QRS morphologies at different output and cycle length to the gold standard of threshold pacing at coupling interval (p=0.9). Conclusion Variations of pacing output and stimulation cycle length during pace mapping does not affect QRS morphology during PVC ablation. Applying a modern automated waveform comparison tool, no advantage was observed when comparing with the gold standard. It is therefore reasonable to assume, that pace mapping can be performed using an easily applicable setting of a fixed burst at maximum pacing output.

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.

A focus on pregnancy course and outcomes of women with zero-fluoroscopy catheter ablation during gestation: a 2-year follow-up study

Abstract Funding Acknowledgements Type of funding sources: None. Background Arrhythmias in pregnant are common clinical problem. Catheter ablation may be required in cases of drug refractory and hemodynamically unstable arrhythmias. Data on further course of pregnancy, perinatal outcomes and results of zero-fluoroscopy catheter ablation in pregnant patients is limited. Purpose we aimed to determine efficacy and safety of zero-fluoroscopy catheter ablation during gestation. Methods 54 pregnant indicated for catheter ablation (Mean age of women was 26.2±3.2 years, mean gestation age 23.3 ±2.4 weeks) due to drug refractory. Further course of pregnancy, perinatal outcomes, complications and arrhythmia recurrence checked during 2-year follow-up. Results Atrioventricular nodal reentrant tachycardia was the most common arrhythmia (n=21; 38.9%). This was followed by Wolff–Parkinson–White syndrome (n=18; 33.3%). In five pregnant was combination of accessory pathways with slow conduction ways (9.3%). Cases of zero-fluoroscopy catheter ablation of ventricular tachycardia (n=2; 3.7%) and premature ventricular contraction (n=8; 14.8%) during gestation were rare. Zero-fluoroscopy catheter ablation successfully performed in all cases (median procedural time was 73±13 minutes). Procedural complication was in one cases (ileofemoral thrombosis). There was no termination of pregnancy after ablation. In five women were increased uterine contractility and uterine blood flow violation (n=5; 9.3%). Preterm delivery was in two cases (3.7%) at 35 and 36 weeks of gestation. Type of delivery was vaginal in the majority (n=42; 77.7%). There were three cases of placental abruption and preeclampsia (5.6%). There were 55 live births (in one case were twins). Fetal birth weight was 3238.7±559.2 grams, 5 minute Apgar was 8.5±1.1. There were no maternal and fetal mortality. At 2-year follow-up there were no arrhythmia recurrence. Conclusions Zero-fluoroscopy catheter ablation during gestation may be safe and effective. It is associated with benign pregnancy course, perinatal and neonatal outcomes.

Similarly high success and low complication rates of catheter ablation for idiopathic premature ventricular contractions from the left and right ventricular outflow tract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation is the first line treatment for idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) but not from the left ventricular outflow tract (LVOT), due to presumed lower success and higher complication rates in the LVOT. In this observational single center study we analyzed success rates and complication rates in patients undergoing catheter ablation for idiopathic PVCs with an inferior axis. Methods Patients undergoing catheter ablation for idiopathic PVCs with an inferior axis at Hannover Heart Rhythm Center between 2012 and 2020 were included. Patients were excluded if no activation mapping could be performed because of low PVC activity. Ablation success was defined as complete suppression of the index PVC at the end of the procedure. Results 108 patients (53% male, age 53 ± 17 years) with predominantly symptomatic (94%) PVCs with one (72%), two (20%) or more (8%) morphologies and a PVC count of 22063 ± 14426 /24h were included. 47 PVCs (44%) were located in the RVOT (21 anterior RVOT and 26 septal RVOT) and 39 PVCs (36%) in the LVOT (11 lateral LVOT, 5 septal LVOT, 8 RCC, 2 ACC, 13 LCC). 14 PVCs (13%) had the origin close to the CS/LV summit and 8 PVCs (7%) in the parahisian region. Overall success rate was 82%. Success rates for RVOT and LVOT origin were 98% (46/47 cases) and 97% (38/39 cases) respectively. No significant differences in procedure time (145 ± 68 vs. 158 ± 72 min), ablation time (441 ± 328 vs. 462 ± 307 sec), fluoroscopy time (496 ± 521 vs. 519 ± 473 sec) or minor complications (5 vs. 8) were observed for outflow tract PVCs, and no major complications occurred in this group. However, 3 major complications and significantly lower success rates were observed for non-outflow tract PVCs (0/8 for parahisian origin, 4/14 (29%) for CS/LV summit origin). 2 patients with a parahisian focus experienced higher degree AV block and 1 patient with an LV summit focus had a pericardial tamponade. Conclusion Catheter ablation of PVCs with LVOT origin can be performed with similarly high success and low complication rates compared to PVCs with RVOT origin, and therefore could be considered as first-line therapy like RVOT PVCs. On the other hand, identification of PVCs with a parahisian or CS/LV summit focus should be aspired before an ablation procedure, as these localizations are associated with poorer ablation outcome and higher complication rates.

Prediction of ablation success of idiopathic premature ventricular contractions with an inferior axis using the twelve-lead electrocardiogram

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation is the first line treatment for idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) but not left ventricular outflow tract (LVOT). However, differentiating the two using the twelve-lead electrocardiogram (ECG) is challenging. As an alternative strategy to guide clinical decision-making, we sought to find ECG criteria that predict outcome of catheter ablation directly rather than focus only. Methods This observational single center study included patients undergoing an ablation procedure for idiopathic PVCs with an inferior axis (positive QRS in leads II, III and aVF) at Hannover Heart Rhythm Center between 2012 and 2020. Patients were excluded if no activation mapping was performed because of low PVC activity. A complete suppression of the index PVC at the end of the ablation procedure was considered as ablation success. PVC axis was estimated with the help of the hexaxial reference system, and as an objective control was also calculated measuring QRS voltages and using three formulas: Arctan (aVF/I), Arctan ((2*II-I)/(Sqr(3)*I)) and +/-Arctan ((2*aVF)/(Sqr(3)*I)). Results The analysis included 108 patients (53% male, age 53 ± 17 years) with a PVC count of 22063 ± 14426 /24h. The dominant PVC had Left Bundle Branch Block (LBBB) like morphology in 80%, a mean transition (TZ)-score of 2.3 ± 1.2 and a mean axis of 87 ± 15°, estimated with the help of the hexaxial system. There was no significant difference between axis as estimated with the help of the hexaxial system compared to calculation via any of the formulas (87 ± 14, 87 ± 12 and 86 ± 16°, respectively). Overall ablation success was 82%. Considering ablation outcome according to the identified PVC localization, 46 of 47 cases (97.9%) of RVOT focus and 38 of 39 cases (97.4%) of LVOT focus were successful. On the other hand, all 8 cases with a parahisian focus were not successful and only 4 of 14 cases (28.6%) with a CS/LV summit focus were successful. Two ECG criteria were found to predict ablation failure: a more leftward PVC axis (p=0.015), which was associated with a parahisian focus (p&amp;lt;0.001), and an early precordial transition compared to the QRS complex during AV-nodal conduction (p=0.016), which was associated with a CS/LV summit focus (p&amp;lt;0.001). Using ROC statistics, a cutoff value of 75° for PVC axis and of 2.75 for TZ-Score index predicted ablation success with a positive predictive value of 93% if neither parameter applied (prediction of ablation failure, if either applied, 53 %). Conclusion Two ECG criteria – a more leftward PVC axis and an early precordial transition compared to sinus rhythm – predicted ablation failure and a parahisian or CS/LV summit focus. These parameters should be considered when evaluating a patient for catheter ablation of PVCs with an inferior axis.