Premature ventricular complexes after catheter ablation for atrial fibrillation: Accounting for regression to the mean.

INTRODUCTION: Prior studies have indicated that the frequency of premature ventricular complexes (PVC) increases after catheter ablation for atrial fibrillation (AF). However, these studies have primarily focused on patients whose PVC burden increased rather than including the full spectrum of outcomes. METHODS AND RESULTS: We performed a single-center retrospective cohort study of consecutive patients who underwent first-time AF ablation from 1/2018 to 12/2022 for paroxysmal or persistent AF and had both preablation and postablation rhythm monitoring within 6 months of the procedure. Patients were excluded if they had prior AF or PVC ablation or were prescribed a class I or III antiarrhythmic medication. Among 2945 patients who underwent AF ablation during the study period, 130 patients underwent first-time AF ablation and received both pre and post ambulatory monitoring. The median PVC burden before ablation was <1%. Most patients (63%) had no change in PVC burden after AF ablation compared with preablation, and patients who had an increase in PVC burden were offset by those with reductions in PVCs. A paired analysis pre- and post-AF ablation showed no significant change in PVC burden (p = .495). CONCLUSION: Although an elevated PVC burden after AF ablation may be seen clinically, the majority of patients have no change in burden. Studies that suggest an increase in PVC burden after AF ablation may suffer from incomplete sample selection and thus omit the important effect of regression to the mean.

Are antiarrhythmic agents indicated in premature ventricular complex-induced cardiomyopathy and when?

INTRODUCTION: Premature ventricular complexes (PVCs) are the most common ventricular arrhythmia that are encountered in the clinical practice. Recent data suggests that high PVC burden may lead to the development of PVC-induced cardiomyopathy (PVC-CM) even in patients without structural heart disease. Treatment for effective suppression of PVCs, can reverse PVC-CM. Both antiarrhythmic drugs (AADs) and catheter ablation (CA) are recognized treatment modalities for any cardiac arrhythmias. However, with increasing preference of CA, the role of AADs needs further defining regarding their efficacy, safety, indications and patient selection to treat PVC-CM. METHODS: To ascertain the role of AADs to treat PVC-CM; whether they are indicated to treat PVC-CM, and if so, when, we interrogated PubMed and other search engines for English language publications with key words premature ventricular complexes (PVCs), cardiomyopathy, anti-arrhythmic drugs, catheter ablation, and pharmacological agents. All publications were carefully reviewed and scrutinized by the authors for their inclusion in the review paper. For illustration of cases, ethical standard was observed as per the 1975 Declaration of Helsinki, and the patient was treated as per the prevailing standard of care. Informed consent was obtained from the patient for conducting the ablation procedure. RESULTS: Our literature search specifically the pharmacological treatment of PVC-CM with AADs revealed significant paradigm shift in treatment approach for PVCs and PVC-induced cardiomyopathy. No major large, randomized control trials of AADs versus CA for PVC-CM were found. We found that beta-blockers and calcium channel blockers are particularly effective in the treatment of PVCs originating from right ventricular outflow tract. For Class Ic AADs - flecainide and propafenone, small clinical studies showed Class Ic AADs to be effective in PVC suppression, but their usage was not recommended in patients with significant coronary artery disease. Mexiletine was found to have modest effect on PVC suppression. Studies showed sotalol to significantly reduce PVCs frequency in patients receiving both low and high doses. Studies also showed amiodarone to have higher successful PVC suppression, but not recommended as a first-line treatment for patients with idiopathic PVCs in the absence of symptoms and left ventricular dysfunction. For dronedarone, no major clinical data were available. CONCLUSIONS: Based on the available data in the literature, we conclude that AADs play important role in the treatment of PVC-induced cardiomyopathy. However, appropriate patient selection criteria are vitally important, and in general terms AADs are indicated or polymorphic PVCs, epicardial PVCs; and when CA procedure is contraindicated, or not feasible or failed.

Arrhythmias as Presentation of Genetic Cardiomyopathy.

There is increasing evidence regarding the prevalence of genetic cardiomyopathies, for which arrhythmias may be the first presentation. Ventricular and atrial arrhythmias presenting in the absence of known myocardial disease are often labelled as idiopathic, or lone. While ventricular arrhythmias are well-recognized as presentation for arrhythmogenic cardiomyopathy in the right ventricle, the scope of arrhythmogenic cardiomyopathy has broadened to include those with dominant left ventricular involvement, usually with a phenotype of dilated cardiomyopathy. In addition, careful evaluation for genetic cardiomyopathy is also warranted for patients presenting with frequent premature ventricular contractions, conduction system disease, and early onset atrial fibrillation, in which most detected genes are in the cardiomyopathy panels. Sudden death can occur early in the course of these genetic cardiomyopathies, for which risk is not adequately tracked by left ventricular ejection fraction. Only a few of the cardiomyopathy genotypes implicated in early sudden death are recognized in current indications for implantable cardioverter defibrillators which otherwise rely upon a left ventricular ejection fraction ≤0.35 in dilated cardiomyopathy. The genetic diagnoses impact other aspects of clinical management such as exercise prescription and pharmacological therapy of arrhythmias, and new therapies are coming into clinical investigation for specific genetic cardiomyopathies. The expansion of available genetic information and implications raises new challenges for genetic counseling, particularly with the family member who has no evidence of a cardiomyopathy phenotype and may face a potentially negative impact of a genetic diagnosis. Discussions of risk for both probands and relatives need to be tailored to their numeric literacy during shared decision-making. For patients presenting with arrhythmias or cardiomyopathy, extension of genetic testing and its implications will enable cascade screening, intervention to change the trajectory for specific genotype-phenotype profiles, and enable further development and evaluation of emerging targeted therapies.

Bipolar radiofrequency ablation of refractory ventricular arrhythmias: results from a multicentre network.

AIMS: Advanced ablation strategies are needed to treat ventricular tachycardia (VT) and premature ventricular complexes (PVC) refractory to standard unipolar radiofrequency ablation (Uni-RFA). Bipolar radiofrequency catheter ablation (Bi-RFA) has emerged as a treatment option for refractory VT and PVC. Multicentre registry data on the use of Bi-RFA in the setting of refractory VT and PVC are lacking. The aim of this Bi-RFA registry is to determine its real-world safety, feasibility, and efficacy in patients with refractory VT/PVC. METHODS AND RESULTS: Consecutive patients undergoing Bi-RFA at 16 European centres for recurring VT/PVC after at least one standard Uni-RFA were included. Second ablation catheter was used instead of a dispersive patch and was positioned at the opposite site of the ablation target. Between March 2021 and August 2024, 91 patients underwent 94 Bi-RFA procedures (74 males, age 62 ± 13, and prior Uni-RFA range 1-8). Indications were recurrence of PVC (n = 56), VT (n = 20), electrical storm (n = 13), or PVC-triggered ventricular fibrillation (n = 2). Procedural time was 160 ± 73 min, Bi-RFA time 426 ± 286 s, and mean Uni-RFA time 819 ± 697 s. Elimination of clinical VT/PVC was achieved in 67 (74%) patients and suppression of VT/PVC in a further 10 (11%) patients. In the remaining 14 patients (15%), no effect on VT/PVC was observed. Three major complications occurred: coronary artery occlusion, atrioventricular block, and arteriovenous fistula. Follow-up lasted 7 ± 8 months. Nineteen patients (61%) remained VT free. ≥80% PVC burden reduction was achieved in 45 (78%). CONCLUSION: These real-world registry data indicate that Bi-RFA appears safe, is feasible, and is effective in the majority of patients with VT/PVC.

Diagnostic reliability of monitoring for premature atrial and ventricular complexes.

AIMS: Short-term ambulatory electrocardiogram (ECG) monitoring is often used to assess premature atrial complex (PAC) and premature ventricular complex (PVC) frequency, but the diagnostic reliability is unknown. The objective of this study was to study the day-to-day variability of PAC and PVC frequency. METHODS AND RESULTS: We used 14-day full-disclosure mobile cardiac telemetry recordings without atrial fibrillation in 8245 US patients aged 17-103 years to calculate the diagnostic reliability of shorter ambulatory ECG recordings compared with 14-day averages. Over 14 days, 1853 patients had ≥500 PACs/day, 410 patients had ≥5000 PACs/day, and 197 patients had ≥10 000 PACs/day; 1640 patients had ≥500 PVCs/day, 354 patients had ≥5000 PVCs/day, and 175 patients had ≥10 000 PVCs/day. After 3 days, the estimated daily PAC frequency differed by ≥50% from the 14-day mean in 25% of patients; for PVCs, the corresponding duration was 7 days. Ten days of monitoring were needed to estimate PAC and PVC frequency within ±20% of the overall 14-day frequency in 80% of patients. For daily PAC and PVC frequencies ≥10 000, single-day estimation had a specificity of 99.3% [95% confidence interval (CI) 99.1-99.5] at a sensitivity of 76.6 (95% CI 70.1-80.4%) for PACs and a 99.6% (95% CI 99.4-99.7%) specificity at 79.4 (95% CI 72.7-85.2) sensitivity for PVCs. After 7 days, the sensitivity increased to 88.8% (95% CI 83.6-92.9) for PACs and 86.9% (95% CI 80.9-91.5%) for PVCs. CONCLUSION: While there is substantial daily variability across most PAC and PVC levels, findings of ≥10 000 PACs or PVCs are highly specific and do not need to be confirmed with longer recordings.

Long-term outcomes of catheter ablation for ventricular arrhythmias: comparing techniques with and without intracardiac echocardiography - what matters?

BACKGROUND: The increasing use of intracardiac echocardiography (ICE) in the ablation of premature ventricular complexes (PVCs) has raised questions about its true efficacy and safety. METHODS: This retrospective study collected the periprocedural complications and PVC burden post ablation. The risk factors of PVC recurrence was further explored. RESULTS: The study included patients treated without ICE (control group, n = 451) and with ICE (ICE group, n = 155) from May 2019 to July 2022. The ICE group demonstrated significantly lower fluoroscopy times and X-ray doses. There were no major complications in the ICE group, and the difference in the occurrence of periprocedural complications between the groups was not statistically significant (p = 0.072). The long-term success rates were similar for the control and ICE groups (89.6% and 87.1%, respectively). The origin of PVCs was identified as the independent factor for ablation success. CONCLUSIONS: The use of ICE did not confer an advantage with regard to long-term success in PVCs ablation. To thoroughly evaluate the safety and effectiveness of ICE in PVCs ablation, a prospective, multicenter, randomized study is warranted.

Relationship between epicardial adipose tissue measured by computed tomography and premature ventricular complexes originating from different sites.

AIMS: This study aims to explore the association between the features of epicardial adipose tissue (EAT) in different zones and premature ventricular complexes (PVCs) originating from different sites by computed tomography (CT). METHODS AND RESULTS: A total of 136 patients who underwent radiofrequency ablation for PVCs were incorporated in this study. One hundred and thirty-six matched controls were included in this study using the case-control method (1:1 matching). PVCs were classified into four subgroups: (1) right ventricular outflow tract (RVOT-PVCs), (2) non-RVOT of the right ventricle (RV-PVCs), (3) left ventricular outflow tract (LVOT-PVCs), and (4) non-LVOT of the left ventricle (LV-PVCs). The volume and density of EAT were quantified by CT. Patients with PVCs had a significantly higher volume and lower density of EAT than the controls (P < 0.001). The LVOT-PVCs and LV-PVCs had a higher left ventricle periventricular EAT volume (LV-EATv) proportion (P < 0.05). The right ventricle periventricular EAT volume (RV-EATv) proportion was higher in ROVT-PVCs and LVOT-PVCs (P < 0.05). RVOT-PVC patients had a higher volume ratio and a smaller density differential (P < 0.05). Patients with LVOT-PVCs had a lower volume ratio and the LV-PVCs showed a greater density differential (P < 0.05). CONCLUSION: Higher volume and lower density of EAT were significantly associated with frequent PVCs. The RVOT-PVC patients had a higher volume ratio and a smaller density differential. The LVOT-PVCs had a lower volume ratio and the LV-PVCs showed a greater density differential. These suggest a link between EAT structural properties and PVCs and a potential role for regional EAT in the development of PVCs.

Relationship Between Epicardial Adipose Tissue Volume and Recurrence After Ablation in Premature Ventricular Complexes.

BACKGROUND: Epicardial adipose tissue (EAT) is recognized as a clinical diagnostic marker for cardiometabolic disease. Thicker EAT may be associated with recurrence of ventricular tachycardia after ablation. The association between EAT volume and recurrence of premature ventricular complexes (PVC) following ablation has not been clarified. We investigated the association between EAT volume and PVC recurrence following radiofrequency catheter ablation.Methods and Results: This retrospective study included 401 patients with PVC undergoing catheter ablation with preprocedural non-contrast computed tomography between 2017 and 2022. The impact of EAT volume in predicting PVC recurrence after ablation was analyzed. The mean (±SD) age of patients was 50.2±13.3 years. Multivariable Cox analysis revealed that a large EAT volume was an independent predictor of PVC recurrence after ablation during a median follow-up of 16.3 months. Kaplan-Meier analysis showed a difference in postablation PVC recurrence between the 2 groups dichotomized around the EAT volume cut-off. The risk of recurrence increased with increasing EAT volume according to restricted cubic spline regression. Furthermore, PVC originating from epicardial locations had larger EAT volumes than those originating from the right ventricular outflow tract. CONCLUSIONS: A large EAT volume was independently associated with PVC recurrence following ablation. Patients with PVC originating from epicardial sites had large EAT volumes. EAT volume may help stratify patients according to their risk of PVC recurrence after ablation.

Echocardiographic assessment of pulmonary capillary wedge pressure in patients with frequent premature ventricular complexes.

BACKGROUND: Premature ventricular complex (PVC) is seen in most individuals. It has been shown that the kinetics-tracking index or Kawasaki-Tanaka index (KT index) strongly predicts pulmonary capillary wedge pressure (PCWP) by noninvasively. KT index was defined as log10 (active LAEF/minimum LAV index). We goaled to assess PCWP non-invasively in patients with frequent PVCs with normal left ventricular systolic functions and to evaluate whether there is an increase in PCWP before systolic and diastolic functions are impaired. METHODS: About 55 patients with frequent PVCs as a patient group and 54 healthy volunteers as a control group were involved to the study. After the conventional echocardiographic examination, the vendor-independent software system (EchoPAC version 202) was used to obtain the time-left atrial volume (LAV) curve. total left atrial emptying function (LAEF), passive LAEF, and active LAEF were calculated to evaluate phasic left atrial (LA) function. In this study, ePCWP was calculated using the KT index, and KT index results and other echocardiographic parameters were compared between study groups. RESULTS: LA anterior-posterior dimension, LA maximum volume index, and LA minimum volume index were significantly larger in the patient group (all p values < .001). Total LAEF were significantly reduced in patients with frequent PVC (p < .001). Estimated pulmonary capillary wedge pressure (ePCWP) by KT index was significantly higher in patients with frequent PVCs (p < .001). CONCLUSIONS: Patients with frequent PVC had increased ePCWP as assessed by KT index.

Relationship between premature ventricular complexes and stroke mortality in the general population.

OBJECTIVES: Predictors for increased stroke mortality identify those who may need closer monitoring and better hospital care. While the link between premature ventricular complexes (PVCs) and incident ischemic stroke has been reported, studies on the association with fatal stroke are non-existent. MATERIALS AND METHODS: We examined the association of PVCs with stroke mortality in 8047 participants (56.5 ± 0.39 years, 53% women, 80.9% Non-Hispanic Whites) without prior history of stroke from the Third National Health and Nutrition Examination Survey. National Death Index was used to identify the date and cause of death. PVCs were detected from 12­lead standard electrocardiograms. Cox proportional hazard analysis was used to examine the association between any PVC with stroke mortality. RESULTS: Approximately 2.1% (n = 134) participants had PVCs at baseline. Over a median follow-up of 22 years, 337 fatal strokes occurred. More strokes occurred in participants with baseline PVCs compared to those without (unadjusted cumulative incidence of stroke 9.5% vs. 2.5% respectively, p-value 0.001). In a multivariable-adjusted model, the presence of PVC was associated with an increased risk of stroke mortality (HR (95%CI): 2.50 (1.15-5.43). This association was stronger in participants with coronary heart disease (CHD) than those without it (HR (95%CI): 5.98 (2.2-16.2) vs. 1.97 (0.75-5.1) respectively; interaction-p = 0.008). CONCLUSIONS: PVCs are associated with an increased risk of stroke mortality, especially among individuals with CHD. Whether improved hospital care or modifying PVCs could change outcomes should be examined in prospective studies.

Ventricular bigeminy characterization in 24-h Holter monitoring from Andersen-Tawil patients: An initial proof of concept versus patients with ischemic heart disease.

AIM: To characterize ventricular bigeminy from 24-h Holter recordings of Andersen-Tawil syndrome (ATS) patients, a first comparison with a large database of post-myocardial infarction (post-MI) patients with frequent premature ventricular complexes (PVC) was performed. METHODS: Baseline Holter recordings from 6 ATS1 patients and 618 post-MI patients were analyzed to assess total number of PVC, quantification of coupling intervals (CI), total number of bigeminy episodes, and percentage of PVC in bigeminy. RESULTS: A non-significant difference in total number of PVCs, mean CI and CI standard deviation was found. The median number of episodes of bigeminy (1038 vs 1; p = 0.004) and of PVC in bigeminy (51.1 vs 0.1%; p = 0.002) was significantly higher in ATS1 patients. Having ≥42 episodes of bigeminy or ≥ 36.1% of PVC in bigeminy distinguish PVC from ATS from post-MI patients with a sensitivity and specificity >80%. CONCLUSION: In this first approach, patients with ATS had a characteristic burden of episodes of ventricular bigeminy, compared with post-MI patients.

Bipolar catheter ablation strategies for outflow tract ventricular arrhythmias refractory to unipolar ablation.

INTRODUCTION: Conventional unipolar catheter ablation (UA) is generally effective for the treatment of outflow tract ventricular arrhythmias (OT-VAs). However, deep foci refractory to UA remains a clinical challenge. The present study evaluated the efficacy and safety of bipolar ablation (BA) in the treatment of OT-VAs refractory to UA. METHODS: A total of 1022 consecutive patients with antiarrhythmic drugs resistant OT-VAs were screened for inclusion in this study, from 1643 VAs cases who underwent catheter ablation in two centers from October 2014 to May 2019. BA was performed after failed sequential UA. The pair of catheters used for BA was positioned on opposing surfaces of the earliest activation (EA) sites or on adjacent anatomical structures. RESULTS: Twelve patients (seven males, mean age 33.3 ± 16.2 years) who met the inclusion criteria were recruited: one patient suffered sustained monomorphic ventricular tachycardia (VT), six patients had frequent premature ventricular contractions (PVCs), and nonsustained VT (NSVT), and five patients had PVCs only. The 24-hPVC/NSVT burden was 36.9 ± 21.7%. The mean distance between two ablation catheters during BA was 11.1 ± 4.3 mm (range 6.5-23.9 mm). The "rS" morphology of the unipolar electrogram was recorded simultaneously in both EA regions in seven cases (58.3%). Acute eradication of VAs was obtained in 10 (83.3%) cases. At a median follow-up of 58 months, 10 patients (83.3%) remained free from VAs. CONCLUSION: BA was highly effective and safe for the treatment of OT-VAs refractory to UA.

M-beat-A novel marker for selective left bundle branch capture.

INTRODUCTION: Premature-ventricular-complexes (template/fixation beat) guided left bundle branch pacing (LBBP) was recently described as a novel method of successful lead deployment by rapid rotations. METHODS: We aimed at analyzing the incidence of a unique morphology template beat, which we labelled as 'M-beat' in patients undergoing PVC-guided LBBP, its ability to predict selective LBB-capture and clinical significance. RESULTS: Overall 210 out of 217 attempted-patients (96.7%) underwent successful LBBP. Template beat was noted in 90.4% patients (n = 190) and M-beat in 32.8%(n = 69). Non-selective to selective capture transition demonstrated in 55.2%(n = 116). The QRS duration of the M-beat was 129.3 ± 13.1ms. Patients were divided into two groups: Group-I with M-beat (n = 69;32.8%) and Group-II without M-beat (n = 141; 67.2%). The mean fluoroscopy-time was significantly less in group-I as compared to group-II (13.1 ± 11.1 vs 16.8 ± 12.04 minutes; p-0.03). Patients in group-II required more attempts as compared to group-I for successful lead deployment (2.8 ± 1.09 vs 2.2 ± 1.04; p - 0.01). Six patients showed loss of R-wave in lead-V1 and 2 showed rise in LBB capture threshold by >1V during follow-up in group-II. M-beat had a specificity of 96.77% and sensitivity of 58.62% (positive-predictive-value-98.55%) to predict selective-LBB capture. Myocardial excitability would not modify the occurrence of M-beat as opposed to capture transition response since it could be demonstrated without pacing protocols. When confirmation of LBB-capture itself would be difficult in patients with baseline LBBB-morphology, M-beat with 42.8% incidence predicted selective capture with 96.7% specificity and 66.04% sensitivity(positive-predictive-value-97.22%). CONCLUSION: M-beat is a marker of transient-selective LBB-capture, independent of the local myocardial excitability with high specificity and positive predictive value irrespective of the baseline QRS morphology.

Selection of an impedance- or magnetic field-based electro-anatomical mapping platform does not affect outcomes of outflow tract premature ventricular complex manual ablation.

Comparative data are virtually missing about the performance of different electro-anatomical mapping (EAM) system platforms on outflow tract (OT) premature ventricular complex (PVC) ablation outcomes with manual ablation catheters. We aimed to compare the acute success-, complication-, and long-term recurrence rates of impedance-based (IMP) and magnetic field-based (MAG) EAM platforms in manual OT PVC ablation. Single-centre, propensity score matched data of 39-39 patients ablated for OT PVCs in 2015-17 with IMP or MAG platforms were analysed. Acute success rate, peri-procedural complications, post-ablation daily PVC burden, and long-term recurrence rates were compared on intention-to-treat basis. Acute success rate was similar in the IMP and MAG group (77 vs. 82%, p = 0.78). There was a single case of femoral pseudo-aneurysm and no cardiac tamponade occurred. PVC burden fell significantly from baseline 24.0% [15.0-30.0%] to 3.3% [0.25-10.5%] (p < 0.001) post-ablation, with no difference between EAM platforms (IMP: 2.6% [0.5-12.0%] vs. MAG: 4.0% [2.0-6.5%]; p = 0.60). There was no significant difference in recurrence-free survival of the intention-to-treat cohort of the IMP and MAG groups (54 vs. 60%, p = 0.82, respectively) during 12 months of follow-up. Ablation with the aid of both impedance- and magnetic field-based EAM platforms can considerably reduce OT PVC burden and give similar acute- and long-term freedom from arrhythmia.

Predictors of positive response to beta-blockers for treatment of premature ventricular complexes.

BACKGROUND: The aim of the present study is to investigate the possible factors that might be predictive of effective antiarrhythmic effect of beta-blockers on premature ventricular complexes (PVC). METHODS: Data of 190 eligible consecutive patients to whom beta-blocker therapy had been initiated for treatment of PVC's were retrospectively evaluated. The Holter recording acquired before beta-blocker initiation and the first Holter acquired after beta blocker initiation during follow up was comprehensively evaluated for each patient. Parameters obtained from pre- and post-beta-blocker 24 h Holter recordings were compared with each other and possible predictors were evaluated for positive response to beta-blocker therapy. RESULTS: Sixty-one patients (32.1%) were observed to respond beta-blocker therapy with at least 50% reduction of daily PVC burden. Patients who responded to beta-blockers had significantly higher ratio of patients who had positive correlation between hourly heart rate and corresponding hourly PVC number (fast HR-PVC status) compared with non-responders (73.8% vs 48.1%, p < 0.001). Binary logistic regression analysis revealed PVC QRS width (Odds ratio: 0.971; p: 0.037) and fast HR-PVC status (Odds ratio: 2.935; p: 0.007) as the independent predictors of positive response to beta-blockers for treatment of PVC. CONCLUSION: Positive correlation between hourly heart rate and PVC incidence was found to be independent positive predictor and PVC QRS width was found to be independent negative predictor of beta-blocker success in our study. This observation might have important clinical implications to guide medical treatment of PVCs in clinical practice.

Effectiveness of medical therapy for treatment of idiopathic frequent premature ventricular complexes.

INTRODUCTION: The relative effectiveness of medical therapy compared with a conservative approach of monitoring in patients with idiopathic frequent premature ventricular complexes (PVCs) is uncertain. We evaluated the effectiveness of medical versus conservative therapy for frequent PVCs. METHODS: Patients with frequent PVCs (≥5%) were prospectively enrolled in this cohort study between 2016 and 2020. In patients with normal cardiac function and no structural heart disease, those receiving medical therapy were compared with controls without therapy. Patients were followed longitudinally for change in PVC burden and with serial echocardiography. RESULTS: Overall, 120 patients met inclusion criteria (mean: 56.5 ± 14.6 years, 54.2% female) with 53 on beta-blockers or calcium channel blockers (BBs/CCBs), 27 on Class I or III antiarrhythmic drugs (AADs), and 40 patients treated conservatively. Median initial PVC burden ranged from 15.5% to 20.6%. The median relative reduction of PVCs was 32.7%, 30.5%, and 81.3%, in the conservative therapy, BBs/CCBs, and AADs cohorts, respectively. AADs had greater PVC reduction compared with BBs/CCBs (p = 0.017) and conservative therapy (p = 0.045). PVC reduction to <1% was comparable across groups at 35.0%, 17.0%, 33.3%, respectively. Four patients (4/120, 3.3%) developed left ventricular dysfunction. Rates of adverse drug reactions and medication discontinuation were similar between groups, with no serious adverse events noted. CONCLUSION: In patients with idiopathic frequent PVCs, BB, and CCB have limited effectiveness in PVC reduction. Class I and III AADs have superior effectiveness for medical therapy in symptomatic patients, but only achieved complete PVC resolution suppression in one-third of patients.

Characterization of the electrophysiological substrate in patients with Barlow's disease.

BACKGROUND: Myxomatous mitral valve prolapse (MVP) and mitral-annular disjunction (Barlow disease) are at-risk for ventricular arrhythmias (VA). Fibrosis involving the papillary muscles and/or the infero-basal left ventricular (LV) wall was reported at autopsy in sudden cardiac death (SCD) patients with MVP. OBJECTIVES: We investigated the electrophysiological substrate subtending VA in MVP patients with Barlow disease phenotype. METHODS: Twenty-three patients with VA were enrolled, including five with syncope and four with a history of SCD. Unipolar (Uni < 8.3 mV) and bipolar (Bi < 1.5 mV) low-voltage areas were analyzed with electro-anatomical mapping (EAM), and VA inducibility was evaluated with programmed ventricular stimulation (PES). Electrophysiological parameters were correlated with VA patterns, electrocardiogram (ECG) inferior negative T wave (nTW), and late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance. RESULTS: Premature ventricular complex (PVC) burden was 12 061.9 ± 12 994.6/24 h with a papillary-muscle type (PM-PVC) in 18 patients (68%). Twelve-lead ECG showed nTW in 12 patients (43.5%). A large Uni less than 8.3 mV area (62.4 ± 45.5 cm2 ) was detected in the basal infero-lateral LV region in 12 (73%) patients, and in the papillary muscles (2.2 ± 2.9 cm2 ) in 5 (30%) of 15 patients undergoing EAM. A concomitant Bi less than 1.5 mV area (5.0 ± 1.0 cm2 ) was identified in two patients. A history of SCD, and the presence of nTW, and LGE were associated with a greater Uni less than 8.3 mV extension: (32.8 ± 3.1 cm2 vs. 9.2 ± 8.7 cm2 ), nTW (20.1 ± 11.0 vs. 4.1 ± 3.8 cm2 ), and LGE (19.2 ± 11.7 cm2 vs. 1.0 ± 2.0 cm2 , p = .013), respectively. All patients with PM-PVC had a Uni less than 8.3 mV area. Sustained VA (ventricular tachycardia 2 and VF 2) were induced by PES only in four patients (one with resuscitated SCD). CONCLUSIONS: Low unipolar low voltage areas can be identified with EAM in the basal inferolateral LV region and in the papillary muscles as a potential electrophysiological substrate for VA and SCD in patients with MVP and Barlow disease phenotype.

Similar outcomes with manual contact force ablation catheters and traditional catheters in the treatment of outflow tract premature ventricular complexes.

AIMS: Unlike in atrial fibrillation ablation, there is a lack of appropriately sized and properly designed studies regarding outflow tract (OT) premature ventricular complex (PVC) ablation outcomes with contact force sensing (CFS) catheters. We aimed to compare the acute success-, complication-, and long-term recurrence rates of manual CFS catheters with traditional irrigated catheters (T) in OT PVC ablation. METHODS AND RESULTS: Single-centre, propensity-matched data of 75-75 patients ablated for right-sided OT (RVOT) or left-sided OT (LVOT) PVCs in 2015-17 with CFS or T catheters were compared. Acute success rate, peri-procedural complications, post-procedural daily PVC burden, and long-term recurrence rates were compared on intention-to-treat basis. Acute success rate equalled 80% in both groups, with no difference in force values in the CFS group comparing successful or failed cases [12.0 (8.75-17.0) vs. 16.0 (10.25-22.25) g, P = 0.21]. There were three cases of pseudo-aneurysm and one cardiac tamponade. PVC burden fell significantly from baseline 22 (15-30)% to 2 (0-10)% (P < 0.0001), with no difference between catheter types [CFS: 1 (0-7)% vs. T: 4 (1-12) %; P = 0.21]. There was no significant difference in recurrence-free survival of CFS and T catheters (58 vs. 59%, P = 0.29) during 12 months of follow-up, respectively. Recurrence in the CFS group did not differ either by the force exerted below or above the median value of 12 g (P = 0.66). CONCLUSION: Both types of catheters can effectively reduce OT PVC burden with minimal serious complication rates. Ablation with CFS or T catheters gives similar acute- and long-term results.

MANual vs. automatIC local activation time annotation for guiding Premature Ventricular Complex ablation procedures (MANIaC-PVC study).

AIMS: To assess potential benefits of a local activation time (LAT) automatic acquisition protocol using wavefront annotation plus an ECG pattern matching algorithm [automatic (AUT)-arm] during premature ventricular complex (PVC) ablation procedures. METHODS AND RESULTS: Prospective, randomized, controlled, and international multicentre study (NCT03340922). One hundred consecutive patients with indication for PVC ablation were enrolled and randomized to AUT (n = 50) or manual (MAN, n = 50) annotation protocols using the CARTO3 navigation system. The primary endpoint was mapping success. Clinical success was defined as a PVC-burden reduction of ≥80% in the 24-h Holter within 6 months after the procedure. Mean age was 56 ± 14 years, 54% men. The mean baseline PVC burden was 25 ± 13%, and mean left ventricular ejection fraction (LVEF) 55 ± 11%. Baseline characteristics were similar between the groups. The most frequent PVC-site of origin were right ventricular outflow tract (41%), LV (25%), and left ventricular outflow tract (17%), without differences between groups. Radiofrequency (RF) time and number of RF applications were similar for both groups. Mapping and procedure times were significantly shorter in the AUT-arm (25.5 ± 14.3 vs. 32.8 ± 12.6 min, P = 0.009; and 54.8 ± 24.8 vs. 67.4 ± 25.2, P = 0.014, respectively), while more mapping points were acquired [136 (94-222) AUT vs. 79 (52-111) MAN; P < 0.001]. Mapping and clinical success were similar in both groups. There were no procedure-related complications. CONCLUSION: The use of a complete automatic protocol for LAT annotation during PVC ablation procedures allows to achieve similar clinical endpoints with higher procedural efficiency when compared with conventional, manual annotation carried out by expert operators.

Electrocardiographic characteristics and ablation of ventricular arrhythmias originating from the basal inferoseptal area.

AIMS: Ventricular arrhythmias (VAs) from the basal inferoseptal (BIS) area are rare and can pose unique challenges during catheter ablation (CA) due to the anatomic complexity. The study sought to describe the electrocardiographic and clinical characteristics of VAs originating from the BIS area. METHODS AND RESULTS: Patients with VAs and successful ablation at the BIS area from 2016 to 2020 were included. The 12-lead electrocardiogram (ECG), intracardiac findings, and outcomes were analysed. Of 482 patients with VAs referred for CA, 17 (3.5%) had successful ablation at BIS area. There were 12 males, mean age was 66.7 ± 9 years, 82% had ejection fraction <50%. Mean baseline premature ventricular complex burden was 28.6 ± 9%. All patients had a leftward superior axis. Left bundle branch block (LBBB) with early transition in V2 was noted in eight patients and right bundle branch block (RBBB) in nine patients. Detailed mapping of the right ventricle (RV) was performed in 15 patients (88%), coronary sinus (CS)/middle cardiac vein (MCV) in 13 (76%), right atrium (RA) adjacent to the inferoseptal process (ISP) of left ventricle (LV) in 5 (29%), ISP-LV in 13 (76%), and epicardium in 2 (12%). Successful ablation site was in LV in 10 (59%), RV in 2 (12%), CS/MCV in 1 (6%), RA in 1 (6%), and epicardium in 2 (12%). Fifteen patients (88%) required mapping in at least two chambers (range 2-5) and seven patients (41%) required ablation in at least two chambers (range 2-3). CONCLUSIONS: Ventricular arrhythmias originating in the BIS are uncommon. The most common ECG patterns were leftward superior axis, LBBB with transition in V2 or RBBB. The VA foci can be endocardial or epicardial and meticulous mapping/ablation from multiple chambers is often required to eliminate these foci successfully.