Impact of catheter ablation for atrial fibrillation on cardiac ventricular electrical activity: assessment of premature ventricular complex burden.

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. 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). 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.

POSTER PRESENTATIONS

Catheter ablation for persistent atrial fibrillation in an elderly patient with cor triatriatum sinister

Premature Ventricular Contractions and Atrial Fibrillation: The Reunion of Distant Relatives?

Research Needs and Priorities for Catheter Ablation of Atrial Fibrillation

Two prospective cohort studies have evaluated incidence of frequent outflow tract (OT) premature ventricular complexes (PVCs) and/or nonsustained ventricular tachycardia following radiofrequency catheter ablation of paroxysmal and persistent atrial fibrillation (AF).1, 2 Both enrolled subjects without ventricular arrhythmias before ablation. Postablation frequent OT ventricular arrhythmias were observed in 11.3% and 3.3%.1, 2 As neither included non-ablation comparison groups, causality remains unclear. In a recent issue of Journal of Cardiovascular Electrophysiology, Choy and colleagues performed a similar study, but included subjects with ventricular arrhythmias before ablation.3 It was limited by the retrospective approach. Also, whether ventricular arrhythmias were of OT origin was not reported. Investigators claimed “patients whose PVC frequency increased postablation were offset by those whose PVC frequency decreased.”3 This was questionable given skewed baseline distribution and lack of granularity in the PVC burden data. Prior research support their selected outcome measures was not cited. For example, a PVC burden threshold of ≥1000/day, used by Wu and colleagues in their study,2 has been considered a moderate-to-high PVC burden that has been associated with new-onset AF.4 Nevertheless, it was notable that ventricular arrhythmias decreased in a number of subjects following catheter ablation. Separate analyses of subjects with frequent ventricular arrhythmias at baseline, from this cohort or a future study, are of high interest. Case reports have provided proof-in-concept that atrial arrhythmias may incite OT ventricular arrhythmias via cross-chamber induction.5, 6 Relationships between atrial arrhythmias and OT ventricular arrhythmias may have broader significance as PVCs may induce monomorphic ventricular tachycardia due to reentry in structural heart disease. Given the high prevalence of AF and/or atrial flutter in such patients,7 the true effect of catheter ablation of AF on PVC burden is deserving of future investigation.

During the past decade, catheter ablation of atrial fibrillation (AF) has emerged as an important treatment option for patients with symptomatic AF refractory to ≥1 antiarrhythmic agents. Electric isolation of the pulmonary vein musculature (PVI) has been identified as the primary end point for both catheter- and surgical-based AF ablation procedures.1 What is less clear is whether the addition of “linear lesions” or ablation of atrial sites demonstrating complex atrial electrograms improves outcome for patients with paroxysmal, persistent, or long-standing persistent AF.2,3 This issue remains an area of active discussion, debate, and investigation. Article see p 269 In this issue of Circulation: Arrhythmia and Electrophysiology , Gaita et al2 report the results of a prospective single-center randomized study of 204 patients who underwent catheter ablation for treatment of paroxysmal or persistent/permanent AF. Patients were stratified according to whether they had paroxysmal (n=125) or persistent/permanent (n=79) AF and were then randomized in a 2:1 fashion to undergo PVI alone or PVI combined with a “roof line” and a “left mitral line.” Follow-up visits that included an ECG, 24-hour Holter, and an echocardiogram were set up at 1, 3, 6, 12, 18, 24, and 30 months and then every year thereafter. If a patient experienced symptoms between follow-up visits, an event monitor was prescribed. A recurrence was defined as a symptomatic or asymptomatic episode of AF or atrial flutter lasting ≥30 seconds after a 2-month blanking period. Patients who developed a recurrence after the blanking period were offered a repeat ablation procedure. The outcome of ablation was evaluated at 12 months of follow-up and at completion of the study. Each patient was followed for a minimum of 3 years. Among the 125 patients with paroxysmal AF, the single-procedure success rate at 12 months was 46% with PVI alone versus …

ORAL PRESENTATION

▪ Abstract Atrial fibrillation is frequently disabling and resistant to antiarrhythmic drugs. Curative treatment by catheter-based ablation has been shown to be feasible either by achieving long linear lesions, mainly in the left atrium, or by targeting the initiating focus, most frequently in the pulmonary veins. This paper reviews the different ablation approaches, their results, potential complications, and relative merits.

AimCurrent literature lacks a definitive threshold of idiopathic premature ventricular complex (PVC) burden for predicting cardiomyopathy (CMP). The main objective of the present study was to evaluate relationship between the PVC burden and left ventricular ejection fraction (LVEF).MethodThis multicenter, cross‐sectional study included 341 consecutive patients with more than 1,000 idiopathic PVC in 24 hr of Holter monitoring admitted to the cardiology clinics between January 2019 and May 2019 in the nineteen different centers. The primary outcome was the LVEF measured during the echocardiographic examination.ResultOverall, the median age was 50 (38–60) and 139 (49.4%) were female. Percentage of median PVC burden was 9% (IQR: 4%–17.4%). Median LVEF was found 60% (55–65). We used proportional odds logistic regression method to examine the relationship between continuous LVEF and candidate predictors. Increase in PVC burden (%) (regression coefficient (RE) −0.644 and 95% CI −1.063, –0.225, p < .001), PVC QRS duration (RE‐0.191 and 95% CI −0.529, 0.148, p = .049), and age (RE‐0.249 and 95% CI −0.442, −0.056, p = .018) were associated with decrease in LVEF. This inverse relationship between the PVC burden and LVEF become more prominent when PVC burden was above 5%. A nomogram developed to estimate the individual risk for decrease in LVEF.ConclusionOur study showed that increase in PVC burden %, age, and PVC QRS duration were independently associated with decrease in LVEF in patients with idiopathic PVC. Also, inverse relationship between PVC burden and LVEF was observed in lower PVC burden than previously known.

Premature ventricular complex (PVC) without structural heart disease is mostly viewed as a benign arrhythmia. However, the high burden of PVC causes cardiomyopathy due to intraventricular dyssynchrony. The effects of ectopic contraction on left ventricular (LV) hemodynamics in the structurally normal heart are unclear. To examine the effect of PVC burden on LV dimension, LV systolic function, and intraventricular blood flow, and to determine whether ectopic ventricular contraction affects LV hemodynamics. Patients aged ≥ 18 years with PVC ≥ 5% on Holter recording were enrolled and divided into groups G1 (5-10%), G2 (10-20%), and G3 (≥ 20%). We excluded patients with structural heart diseases, pacemakers, and LV systolic dysfunction [LV ejection fraction (LVEF) < 50%]. Clinical characteristics and routine transthoracic echocardiography parameters were compared. The end-systolic LV internal dimension increased according to the PVC burden from G1 to G3 (p = 0.001). LVEF was inversely associated with PVC burden from G1 to G3 (p = 0.002). The same pattern was seen for LV outflow tract (LVOT) maximal velocity (p = 0.005) and maximal pressure gradient (PG) (p = 0.005), LVOT velocity time integral (VTI) (p = 0.03) and LV stroke volume index (LVSI) (p = 0.008). Systolic function and LV end-systolic dimension were inversely associated with PVC burden. Decreased LVOT flow velocity and PG were related to increased PVC burden. LVOT VTI and LVSI were smaller when the PVC burden exceeded 20%. These negative hemodynamic manifestations of idiopathic PVC were considerable even in structure normal hearts, hence the early elimination of PVC is strongly advised.

Wide-area antral pulmonary vein and posterior wall isolation by way of segmental nonocclusive applications using a novel radiofrequency ablation balloon

A new era of atrial fibrillation (AF) treatment began in 1997–1998 with the discovery that triggers within the pulmonary veins initiate AF and reports that elimination of these triggers is successful in treating AF in its paroxysmal form.1–3 However, in patients with persistent AF, the success rate of exclusive pulmonary vein isolation is substantially lower.4,5 To improve the outcome of persistent AF ablation, different ablation strategies have been explored, but to date the optimal strategy has not been defined. Although some groups argue that limited ablation, including pulmonary vein isolation and, if present, ablation of nonpulmonary vein triggers, is sufficient for persistent AF ablation, other groups, including ours, favor more extensive, substrate-based ablation in addition to pulmonary vein isolation. In this review, we will discuss the rationale for a substrate-based ablation strategy to treat persistent AF and show why elimination of triggers is not sufficient in most patients with persistent AF. Response by Roten et al on p 1232 In a simple model, an electric impulse in AF can form because of abnormalities in impulse generation (triggers) or can result from abnormal impulse propagation (reentry). By a strict definition, a trigger is a focal source of new impulse generation. The mechanism by which a new impulse can form is either abnormal automaticity or triggered activity. Trigger-ablation protocols target these sources of new impulse generation. Abnormal impulse propagation, on the other hand, depends on altered substrate properties causing nonuniform or slowed conduction. This in turn causes multiple forms of wave reentry thought to be responsible for AF perpetuation: random reentry (multiple wavelets), macro- and microreentry, or functional reentry (rotors). Substrate-based ablation strategies aim to abate abnormal impulse propagation and interrupt any form of atrial reentry. Triggers of paroxysmal AF are mainly located in the pulmonary …

BackgroundHigh burden of premature ventricular complex (PVC) leads to increased cardiovascular mortality. A recent nationwide population‐based study demonstrated that PVC is associated with an increased risk of atrial fibrillation (AF). However, the relationship between PVC burden and new‐onset AF has not been investigated. The purpose of the study is to elucidate whether PVC burden is associated with new‐onset AF.Methods and ResultsWe designed a single‐center, retrospective, large population‐based cohort study to evaluate the role of PVC burden and new‐onset AF in Taiwan. Patients who were AF naïve with PVC were divided into the low burden group (<1000/day) and moderate‐to‐high burden group (≥1000/day) based on the 24‐h Holter ECG report. New‐onset AF was defined as a new or first detectable event of either a persistent or paroxysmal AF. A total of 16 030 patients who were AF naïve and underwent 24‐h Holter ECG monitoring were enrolled in this study, with a mean follow‐up time of 973 days. A propensity score‐matched analysis demonstrated that the moderate‐to‐high burden PVC group had a higher risk of developing new‐onset AF than that of the low burden PVC group (4.91% versus 2.73%, P<0.001). Multivariate Cox regression analysis showed that moderate‐to‐high burden of PVC is an independent risk factor for new‐onset AF. The Kaplan–Meier analysis demonstrated that patients with moderate‐to‐high PVC burden were associated with higher risk of new‐onset AF (log‐rank P<0.001).ConclusionsPVC burden is associated with new‐onset AF. Patients with moderate‐to‐high PVC burden are at a higher risk of new‐onset AF.RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NCT03877614.

BackgroundCatheter ablation (CA) is a key treatment for atrial fibrillation (AF), with international guidelines now endorsing class I indications for its use in various clinical contexts. Pulsed field ablation (PFA) and very high-power short-duration (vHPSD) radiofrequency ablation are recent technologies for AF treatment. However, the procedural performance, safety, and acute effectiveness of PFA compared to vHPSD are not yet well established.ObjectiveThis study aimed to compare PFA with vHPSD for the management of paroxysmal and persistent AF.MethodsWe conducted an observational, single-center study enrolling 90 consecutive patients (mean age 61.9 ± 9.9; 23.3% female) with paroxysmal (n=74) or persistent (n=16) AF. Patients were treated with either a bidirectional, variable loop size (25–35 mm) ablation and mapping PFA catheter (n=45; persistent AF n=8) or a vHPSD catheter with microelectrodes and 6 thermocouples for real-time temperature monitoring during ablation (90 W, 4 seconds; n=45; persistent AF n=8) between 2020 and 2024. Pulmonary vein isolation (PVI) was the primary efficacy endpoint. The primary safety endpoint was a composite of procedure-related complications.ResultsDemographic characteristics were similar between the two groups (Table 1). Successful PVI was achieved in all patients, with shorter procedure durations in the PFA group (68.8 ± 17.9 minutes) compared to vHPSD (113.6 ± 30.6 minutes; p = 0.00054). This difference remained significant after propensity score matching (n=42; PFA, 70 ± 18.1 minutes; vHPSD, 112.8 ± 31.5 minutes; p = 0.000577) and when stratifying by several subgroups, including isolated PVI, PVI plus cavo-tricuspid isthmus (CTI) ablation, paroxysmal AF, persistent AF, and posterior wall ablation (Table 2). Fluoroscopy time was shorter for PFA but not significantly different (PFA, 10.25 ± 5.7 minutes; vHPSD, 11 ± 6.45 minutes; p = 0.56). PFA was associated with more frequent use of general anesthesia (p < 0.0001). Primary safety outcome events occurred in 1 patient (1.1%), with low rates in both groups (PFA, 0%; vHPSD, 2.2%).ConclusionIn this single-center experience, PFA was associated with more frequent use of general anesthesia, shorter procedural times, and similar fluoroscopy exposure compared to vHPSD ablation, with both techniques exhibiting comparable safety and acute efficacy.Table 1:Demographic Characteristics Table 2:Procedural Details