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Background The success of pulmonary vein isolation (PVI) is reduced in persistent AF (PsAF) compared to paroxysmal AF. Adjunctive ablation strategies have failed to show consistent incremental benefit over PVI alone in randomized studies. The left atrial posterior wall is a potential source of non-PV triggers and atrial substrate which may promote the initiation and maintenance of PsAF. Adding posterior wall isolation (PWI) to PVI had shown conflicting outcomes, with earlier studies confounded by methodological limitations. Objectives To determine whether combining PWI with PVI significantly improves freedom from AF recurrence, compared to PVI alone, in patients with PsAF. Methods This is a multi-center, prospective, international randomized clinical trial. 338 patients with symptomatic PsAF refractory to anti-arrhythmic therapy (AAD) will be randomized to either PVI alone or PVI with PWI in a 1:1 ratio. PVI involves wide antral circumferential pulmonary vein (PV) isolation, utilizing contact force sensing ablation catheters. PWI involves the creation of a floor line connecting the inferior aspect of the PVs, and a roof line connecting the superior aspect of the PVs. Follow up is for a minimum of 12 months with rhythm monitoring via implantable cardiac device and/or loop monitor, or frequent intermittent monitoring with an ECG device. The primary outcome is freedom from any documented atrial arrhythmia of > 30 seconds off AAD at 12 months, after a single ablation procedure. Conclusions This randomized study aims to determine the success and safety of adjunctive PWI to PVI in patients with persistent AF.

Objectives This study sought to report P-wave morphology (PWM) from a series of paraseptal (PS) atrial tachycardia (AT), revise then prospectively evaluate a simplified PWM algorithm against a contemporary consecutive cohort with focal AT. Background The 2006 PWM algorithm was useful in predicting the origin of focal AT. An updated algorithm was developed given advances in multipolar 3-dimensional mapping, potential limitations of PWM in separating PS sites, and a renewed interest in the P-wave in mapping non–pulmonary vein triggers. Methods The PWM from a consecutive series of 67 patients with PS AT were analyzed. PS sites included were coronary sinus ostium, perinodal, left and right septum, septal tricuspid annulus, superior mitral annulus, and noncoronary cusp. Next the P-wave algorithm was revised and prospectively evaluated by 3 blinded assessors. Results The P-wave for PS sites was neg/pos (n = 50), iso/pos (n = 10), or isoelectric (n = 4) in lead V1 (96%). The P-wave algorithm was modified and prospectively applied to 30 consecutive patients with focal AT who underwent successful ablation. Foci (n = 30) originated from the right atrium (33.3%), left atrium (30%), and PS (36.7%). Using the PW algorithm, the correct anatomic location was identified in 93%. Incorrect interpretation of the terminal positive P-wave component (n = 3) and initial negative P-wave deflection (n = 1) in lead V1 misidentified 4 paraseptal cases. Conclusions The revised PWM algorithm offers a simplified and accurate method of localizing the responsible site for focal AT. The P-wave remains an important first step in mapping atrial arrhythmias.

Objectives This study sought to describe expected changes in a mirror-image prone electrocardiogram (ECG) compared with normal supine, including a range of cardiac conditions. Background Unwell COVID-19 patients are at risk of cardiac complications. Prone ventilation is recommended but poses practical challenges to acquisition of a 12-lead ECG. The effects of prone positioning on the ECG remain unknown. Methods 100 patients each underwent 3 ECGs: standard supine front (SF); prone position with precordial leads attached to front (PF); and prone with precordial leads attached to back in a mirror image to front (PB). Results Prone positioning was associated with QTc prolongation (PF 437 ± 32 ms vs. SF 432 ± 31 ms; p, Central Illustration

Background: The diagnostic work-up for cardiac arrest from ventricular tachyarrhythmias occurring in younger adults and structurally normal hearts is variable and often incomplete. Methods: We reviewed records for all recipients of a secondary prevention implantable cardiac defibrillator (ICD) younger than 60 years at a single quaternary referral hospital from 2010-2021. Patients were included if they had unexplained ventricular arrhythmias (UVA) and absence of structural heart disease on echocardiogram, normal coronary assessment and no clear diagnostic features on ECG. We specifically evaluated the adoption rate of five modalities of ‘second-line’ cardiac investigations: cardiac magnetic resonance imaging (CMR), exercise ECG, flecainide challenge, electrophysiology study (EPS) and genetic testing. We also evaluated patterns of anti-arrhythmic drug therapy and device-detected arrhythmias and compared them with secondary prevention ICD recipients with a clear aetiology found on initial assessment. Results: 102 recipients of a secondary prevention ICD under the age of 60 were analysed. 39 patients (38.2%) were identified with UVA and were compared with the remaining 63 patients with VA of clear aetiology (61.8%). UVA patients were younger (35.6 ± 13.0 years vs 46.0 ± 8.6 years, pConclusion: In this real-world analysis of patients with UVA, the diagnostic work-up is often incomplete. While CMR was increasingly utilized at our institution, investigations for channelopathies and genetic causes appear to be underutilized. Implementation of a systematic protocol for work-up of these patients requires further study.

AimsRadiofrequency (RF) ablation for pulmonary vein isolation (PVI) in atrial fibrillation (AF) is associated with the risk of oesophageal thermal injury (ETI). Higher power short duration (HPSD) ablation results in preferential local resistive heating over distal conductive heating. Although HPSD has become increasingly common, no randomized study has compared ETI risk with conventional lower power longer duration (LPLD) ablation. This study aims to compare HPSD vs. LPLD ablation on ETI risk.Methods and resultsEighty-eight patients were randomized 1:1 to HPSD or LPLD posterior wall (PW) ablation. Posterior wall ablation was 40 W (HPSD group) or 25 W (LPLD group), with target AI (ablation index) 400/LSI (lesion size index) 4. Anterior wall ablation was 40–50 W, with a target AI 500–550/LSI 5–5.5. Endoscopy was performed on Day 1. The primary endpoint was ETI incidence. The mean age was 61 ± 9 years (31% females). The incidence of ETI (superficial ulcers n = 4) was 4.5%, with equal occurrence in HPSD and LPLD (P = 1.0). There was no difference in the median value of maximal oesophageal temperature (HPSD 38.6°C vs. LPLD 38.7°C, P = 0.43), or the median number of lesions per patient with temperature rise above 39°C (HPSD 1.5 vs. LPLD 2, P = 0.93). Radiofrequency ablation time (23.8 vs. 29.7 min, P < 0.01), PVI duration (46.5 vs. 59 min, P = 0.01), and procedure duration (133 vs. 150 min, P = 0.05) were reduced in HPSD. After a median follow-up of 12 months, AF recurrence was lower in HPSD (15.9% vs. LPLD 34.1%; hazard ratio 0.42, log-rank P = 0.04).ConclusionHigher power short duration ablation was associated with similarly low rates of ETI and shorter total/PVI RF ablation times when compared with LPLD ablation. Higher power short duration ablation is a safe and efficacious approach to PVI.

AIMS: The impact of atrial fibrillation (AF) ablation in early heart failure with preserved ejection fraction (HFpEF) is unknown. Our aim was to determine the impact of AF ablation on symptoms and exercise haemodynamic parameters of early HFpEF. METHODS AND RESULTS: Symptomatic AF patients referred for index AF ablation with ejection fraction ≥50% underwent baseline quality of life questionnaires, echocardiography, cardiac magnetic resonance imaging, exercise right heart catheterisation (exRHC), and brain natriuretic peptide (BNP) testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15 mmHg or peak exercise PCWP ≥25 mmHg. Patients with HFpEF were offered AF ablation and follow-up exRHC ≥6 months post-ablation. Of 54 patients undergoing baseline evaluation, 35 (65%) had HFpEF identified by exRHC. HFpEF patients were older (64 ± 10 vs. 54 ± 13 years, P

Objectives This study sought to determine the long-term outcomes of restoring sinus rhythm with catheter ablation (CA). Background The CAMERA-MRI (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Heart Failure—An MRI-Guided Multicenter Randomized Controlled Trial) study demonstrated that restoration of sinus rhythm with CA significantly improved left ventricular ejection fraction (LVEF) compared with medical rate control (MRC) at 6 months in persistent atrial fibrillation and otherwise unexplained systolic heart failure. However, the long-term outcomes have not been reported. Methods Patients enrolled in the CAMERA-MRI study were followed for 4 years with echocardiogram and cardiac magnetic resonance. CA involved pulmonary vein isolation and posterior left atrial wall isolation in 94%. Patients crossed over to CA after 6-month study duration. Arrhythmia burden was determined with implanted cardiac monitors or cardiac devices. Results Sixty-six patients (age 62 ± 10 years, atrial fibrillation duration of 22 ± 16 months, and LVEF 33 ± 9%) were randomized 1:1 to CA versus MRC. Eighteen of 33 patients crossed over from MRC group to CA group. At 4.0 ± 0.9 years, atrial fibrillation recurred in 27 patients (57%) in the CA group with a mean burden of 10.6 ± 21.2% after 1.4 ± 0.6 procedures. There was an absolute increase in LVEF with CA of 16.4 ± 13.3% compared with 8.6 ± 7.6% in MRC (p = 0.001). In the CA group, the absence of ventricular late gadolinium enhancement was associated with a greater improvement in absolute LVEF (19 ± 13% vs. 10 ± 11% in the late gadolinium enhancement–positive group; p = 0.04) and LVEF normalization in 19 patients (58%) versus 4 patients (18%) in the late gadolinium enhancement–positive group (p = 0.008) at 4.0 ± 0.9 years follow-up. Conclusions CA is superior to MRC in improving LVEF in the long term in patients with atrial fibrillation and systolic heart failure. The greatest recovery in systolic function was demonstrated in the absence of ventricular fibrosis on cardiac magnetic resonance.

Background Multipolar catheters provide high-density mapping which may reduce the procedural duration and improve the success of catheter ablation (CA) for focal arrhythmias. The high-density grid (HDG) catheter is a 16 electrode mapping catheter with bipole recordings at orthogonal splines. The aim of this study is to compare the clinical and procedural features from a cohort who underwent CA for focal arrhythmias using multipolar mapping (MPM) with age and case-matched cohort using point-by-point (PbyP) mapping. Methods Consecutive patients undergoing CA for focal arrhythmias between October 2018 and January 2020 guided by MPM were compared with PbyP mapping with the ablation catheter over a similar period. Demographics, procedural features, and outcomes were compared. Results A total of 54 patients (27 in MPM vs. 27 in PbyP mapping) underwent CA for 68 focal arrhythmias (26 atrial and 42 ventricular). In the MPM group, the electrogram at the successful site was significantly earlier (39 ± 11 ms) than in the PbyP group (33 ± 7 ms; p = .02). In the MPM group, the mapping time (35 ± 24 vs. 53 ± 31 min in PbyP; p = .03) and procedural duration (126 ± 42 vs. 153 ± 39 min in PbyP; p = .02) were significantly shorter. There was no significant difference in radiofrequency and fluoroscopy times, acute procedural success, and arrhythmia recurrence. Conclusion MPM with the HDG catheter for focal tachycardias identified earlier activation times and was associated with shorter mapping and procedure duration with equivalent success to PbyP mapping.

Background Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF). Objective The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men. Methods We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these. Results A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm2; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P Conclusion Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA.

ImportancePulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison.ObjectiveTo compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation.Design, Setting, and ParticipantsInvestigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022.InterventionsThe PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone.Main Outcomes and MeasuresPrimary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications.ResultsAmong 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, –1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P = .98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P = .57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P = .36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P = .47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P P Conclusions and RelevanceIn patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF.Trial Registrationanzctr.org.au Identifier: ACTRN12616001436460

Background: Population studies have demonstrated a range of sex differences including a higher prevalence of atrial fibrillation (AF) in men and a higher risk of AF recurrence in women. However, the underlying reasons for this higher recurrence are unknown. This study evaluated whether sex-based electrophysiological substrate differences exist to account for worse AF ablation outcomes in women. Methods: High-density electroanatomic mapping of the left atrium was performed in 116 consecutive patients with AF. Regional analysis was performed across 6 left atrium segments. High-density maps were created using a multipolar catheter (Biosense Webster) during distal coronary sinus pacing at 600 and 300 ms. Mean voltage and conduction velocity was determined. Complex fractionated signals and double potentials were manually annotated. Results: Overall, 42 (36%) were female, mean age was 61±8 years and AF was persistent in 52%. Global mean voltage was significantly lower in females compared with males at 600 ms (1.46±0.17 versus 1.84±0.15 mV, P P =0.013) pacing. These differences were seen uniformly across the left atrium. Females demonstrated significant conduction velocity slowing (34.9±6.1 versus 44.1±6.9 cm/s, P =0.002) and greater proportion of complex fractionated signals (9.9±1.7% versus 6.0±1.7%, P =0.014). After a median follow-up of 22 months (Q1–Q3: 15–29), females had significantly lower single-procedure (22 [54%] versus 54 [75%], P =0.029) and multiprocedure (24 [59%] versus 60 [83%], P =0.005) arrhythmia-free survival. Female sex and persistent AF were independent predictors of single and multiprocedure arrhythmia recurrence. Conclusions: Female patients demonstrated more advanced atrial remodeling on high-density electroanatomic mapping and greater post-AF ablation arrhythmia recurrence compared with males. These changes may contribute to sex-based differences in the clinical course of females with AF and in part explain the higher risk of recurrence. Graphic Abstract: A graphic abstract is available for this article.

Observational studies report that obstructive sleep apnea (OSA) is associated with an increasingly remodeled atrial substrate in atrial fibrillation (AF). However, the impact of OSA management on the electrophysiologic substrate has not been evaluated.In this study, the authors sought to determine the impact of OSA management on the atrial substrate in AF.We recruited 24 consecutive patients referred for AF management with at least moderate OSA (apnea-hypopnea index [AHI] ≥15). Participants were randomized in a 1:1 ratio to commence continuous positive airway pressure (CPAP) or no therapy (n = 12 CPAP; n = 12 no CPAP). All participants underwent invasive electrophysiologic study (high-density right atrial mapping) at baseline and after a minimum of 6 months. Outcome variables were atrial voltage (mV), conduction velocity (m/s), atrial surface area 0.5 mV (%), proportion of complex points (%), and atrial effective refractory periods (ms). Change between groups over time was compared.Clinical characteristics and electrophysiologic parameters were similar between groups at baseline. Compliance with CPAP therapy was high (device usage: 79% ± 19%; mean usage/day: 268 ± 91 min) and resulted in significant AHI reduction (mean reduction: 31 ± 23 events/h). There were no differences in blood pressure or body mass index between groups over time. At follow-up, the CPAP group had faster conduction velocity (0.86 ± 0.16 m/s vs 0.69 ± 0.12 m/s; P (time × group) = 0.034), significantly higher voltages (2.30 ± 0.57 mV vs 1.94 ± 0.72 mV; P 0.05), and lower proportion of complex points (8.87% ± 3.61% vs 11.93% ± 4.94%; P = 0.011) compared with the control group. CPAP therapy also resulted in a trend toward lower proportion of atrial surface area 0.5 mV (1.04% ± 1.41% vs 4.80% ± 5.12%; P = 0.065).CPAP therapy results in reversal of atrial remodeling in AF and provides mechanistic evidence advocating for management of OSA in AF.

Objectives This study sought to determine the impact of rate and direction on left atrial (LA) substrate. Background The extent to which substrate mapped in sinus rhythm varies according to cycle length and direction of wave front propagation is unknown. Methods A total of 73 consecutive patients with atrial fibrillation (AF) underwent electroanatomic LA mapping before pulmonary vein isolation using multipolar catheter during distal coronary sinus (CS) pacing at 600 ms and 300 ms. Additional maps were created during left superior pulmonary vein pacing at 300 ms. Bipolar voltage, conduction velocity (CV), and complex signals were determined. Results Mean age was 61 ± 9 years, 67% were men, and 53% had persistent AF. Global mean voltage was lower with CS pacing at 300 ms compared with 600 ms (1.56 ± 0.47 mV vs. 1.74 ± 0.48 mV; p Conclusions In patients with AF, variation in cycle length and direction of wave front activation produce both generalized and regional changes in voltage, CV, and complex fractionation, resulting in significant changes in substrate maps. This study highlights the potential limitations of static low-voltage maps to identify the AF ablation target zone.

Objectives: This study sought to determine the long-term right atrial (RA) electrical and structural changes in a subgroup from the CAMERA-MRI (Catheter Ablation Versus Medical Rate Control...

Atrial fibrillation and heart failure (HF) frequently coexist and are associated with a significant increase in morbidity and mortality. Despite the shared common risk factors atrial fibrillation and HF subtypes exacerbate each other. This review provides an overview of the pathophysiologic relationship between atrial fibrillation and the two most common types of heart failure syndromes: HF with reduced ejection fraction and HF with preserved ejection fraction.

Background Regular alcohol intake is an important modifiable risk factor associated with atrial fibrillation (AF) and left atrial (LA) dilation. Objective The purpose of this study was to determine the impact of different degrees of alcohol consumption on atrial remodeling using high-density electroanatomic mapping. Methods We enrolled 75 patients before AF ablation to undergo high-density LA mapping (CARTO, Biosense Webster) using a multipolar catheter. The Confidense algorithm was used to create maps during distal coronary sinus pacing at 600 ms. Bipolar voltage and complex atrial activity were assessed, and isochronal activation maps were created to determine global conduction velocity (CV). Patients were classified as lifelong nondrinkers, mild drinkers (2–7 drinks/week), or moderate drinkers (8–21 drinks/week). Results High-density electroanatomic mapping (mean 1016 ± 445 points per patient) was performed on 25 lifelong nondrinkers, 25 mild drinkers (4.4 ± 2.3 drinks/week), and 25 moderate drinkers (14.0 ± 4.2 drinks/week). Moderate drinkers had significantly lower mean global bipolar voltages (1.53 ± 0.62 mV vs 1.89 ± 0.45 mV; P = .02), slower CV (33.5 ± 14.4 cm/s vs 41.7 ± 12.1 cm/s; P = .04), and a higher proportion of complex atrial potentials (7.8% ± 4.7% vs 4.5% ± 2.7%; P = .004) compared to nondrinkers. Global voltage and CV did not differ significantly in mild drinkers, but there was a significant increase in global complex potentials (6.6% ± 4.6%; P = .04) and regional low-voltage zones ( Conclusion Regular moderate alcohol consumption, but not mild consumption, is an important modifiable risk factor for AF associated with lower atrial voltage and conduction slowing. These electrical and structural changes may explain the propensity to AF in regular drinkers.

BACKGROUND: Catheter ablation is highly effective for atrioventricular nodal re-entrant tachycardia (AVNRT). Generally junctional rhythm (JR) is an accepted requirement for successful ablation however there is a lack of detailed prospective studies to determine the characteristics of JR and the impact on slow pathway conduction. METHODS: Multicentre prospective observational study evaluating the impact of individual radiofrequency (RF) applications in typical AVNRT (slow/fast). Characteristics of JR during ablation were documented and detailed testing was performed after every RF application to determine outcome. Procedural success was defined as ≤1 AV nodal echo. RESULTS: Sixty-seven patients were included (mean age 53 ± 18years, 57% female and a history of SVT 2.9 ± 4.7 years). RF (50w, 60°) ablation for AVNRT was applied in 301 locations with JR in 178 (59%). Successful slow pathway modification was achieved in 66 (99%) patients with slow pathway block in 30 (46%). Success was associated with JR in all patients. Success was achieved in six patients with RF

The impact of atrial fibrillation (AF) ablation in early heart failure with preserved ejection fraction (HFpEF) is unknown. Our aim was to determine the impact of AF ablation on symptoms and exercise haemodynamic parameters of early HFpEF.Symptomatic AF patients referred for index AF ablation with ejection fraction ≥50% underwent baseline quality of life questionnaires, echocardiography, cardiac magnetic resonance imaging, exercise right heart catheterisation (exRHC), and brain natriuretic peptide (BNP) testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15 mmHg or peak exercise PCWP ≥25 mmHg. Patients with HFpEF were offered AF ablation and follow-up exRHC ≥6 months post-ablation. Of 54 patients undergoing baseline evaluation, 35 (65%) had HFpEF identified by exRHC. HFpEF patients were older (64 ± 10 vs. 54 ± 13 years, P 0.01), and more frequently female (54% vs. 16%, P 0.01), hypertensive (63% vs. 16%, P 0.001), and suffering persistent AF (66% vs. 11%, P 0.001), compared to those without HFpEF. Twenty HFpEF patients underwent AF ablation and follow-up exRHC 12 ± 6 months post-ablation. Nine (45%) patients no longer fulfilled exRHC criteria for HFpEF at follow-up. Patients remaining arrhythmia free (n = 9, 45%) showed significant improvements in peak exercise PCWP (29 ± 4 to 23 ± 2 mmHg, P 0.01) and Minnesota Living with Heart Failure (MLHF) score (55 ± 30 to 22 ± 30, P 0.01) while the remainder did not (PCWP 31 ± 5 to 30.0 ± 4 mmHg, P = NS; MLHF score 55 ± 23 to 25 ± 20, P = NS).Heart failure with preserved ejection fraction frequently coexists in patients with symptomatic AF and preserved ejection fraction. Restoration and maintenance of sinus rhythm in patients with comorbid AF and HFpEF improves haemodynamic parameters, BNP and symptoms associated with HFpEF.

This study sought to report P-wave morphology (PWM) from a series of paraseptal (PS) atrial tachycardia (AT), revise then prospectively evaluate a simplified PWM algorithm against a contemporary consecutive cohort with focal AT.The 2006 PWM algorithm was useful in predicting the origin of focal AT. An updated algorithm was developed given advances in multipolar 3-dimensional mapping, potential limitations of PWM in separating PS sites, and a renewed interest in the P-wave in mapping non-pulmonary vein triggers.The PWM from a consecutive series of 67 patients with PS AT were analyzed. PS sites included were coronary sinus ostium, perinodal, left and right septum, septal tricuspid annulus, superior mitral annulus, and noncoronary cusp. Next the P-wave algorithm was revised and prospectively evaluated by 3 blinded assessors.The P-wave for PS sites was neg/pos (n = 50), iso/pos (n = 10), or isoelectric (n = 4) in lead VThe revised PWM algorithm offers a simplified and accurate method of localizing the responsible site for focal AT. The P-wave remains an important first step in mapping atrial arrhythmias.

This study sought to assess the atrial electrophysiological properties and post-ablation outcomes in patients with atrial fibrillation (AF) with and without the rs2200733 single nucleotide variant.The phenotype associated with chromosome 4q25 of the AF-susceptibility locus remains unknown.In this study, 102 consecutive patients (ages 61 ± 9 years, 64% male) with paroxysmal or persistent AF were prospectively recruited prior to ablation. Patients were genotyped for rs2200733 and high-density left atrial (LA) electroanatomic maps were created using a multipolar catheter during distal coronary sinus (CS) pacing at 600 ms. Voltage, conduction velocity (CV), CV heterogeneity, and fractionated signals of 6 LA segments were determined. Arrhythmia recurrence was assessed by continuous device (51%) and Holter monitoring.Overall, 41 patients (40%) were single nucleotide variant carriers (38 heterozygous, 3 homozygous). A mean of 2,239 ± 852 points per patient were collected. Carriers had relatively increased CV heterogeneity (45.7 ± 7.5% vs. 35.9 ± 2.3%; p 0.001), complex signals (9.4 ± 2.9% vs 6.0 ± 1.2%; p = 0.008), regional LA slowing, or conduction block (31.7 ± 8.2% vs. 17.9 ± 1.9%; p = 0.013) particularly in the posterior and lateral walls. There were no differences in CV, voltage, atrial refractoriness, or sinus node function. At follow-up (median: 27 months; range 19 to 31 months), carriers had lower arrhythmia-free survival (51% vs. 80%; p = 0.003). On multivariable analysis, carrier status was independently associated with CV heterogeneity (p = 0.001), complex signals (p = 0.002), and arrhythmia recurrence (p = 0.019).These data provide the first evidence that the rs2200733-tagged haplotype alters LA electrical remodeling and is a determinant of long-term outcome following AF ablation. The molecular mechanisms underpinning these changes warrant further investigation.

This study sought to determine the long-term outcomes of restoring sinus rhythm with catheter ablation (CA).The CAMERA-MRI (Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Heart Failure-An MRI-Guided Multicenter Randomized Controlled Trial) study demonstrated that restoration of sinus rhythm with CA significantly improved left ventricular ejection fraction (LVEF) compared with medical rate control (MRC) at 6 months in persistent atrial fibrillation and otherwise unexplained systolic heart failure. However, the long-term outcomes have not been reported.Patients enrolled in the CAMERA-MRI study were followed for 4 years with echocardiogram and cardiac magnetic resonance. CA involved pulmonary vein isolation and posterior left atrial wall isolation in 94%. Patients crossed over to CA after 6-month study duration. Arrhythmia burden was determined with implanted cardiac monitors or cardiac devices.Sixty-six patients (age 62 ± 10 years, atrial fibrillation duration of 22 ± 16 months, and LVEF 33 ± 9%) were randomized 1:1 to CA versus MRC. Eighteen of 33 patients crossed over from MRC group to CA group. At 4.0 ± 0.9 years, atrial fibrillation recurred in 27 patients (57%) in the CA group with a mean burden of 10.6 ± 21.2% after 1.4 ± 0.6 procedures. There was an absolute increase in LVEF with CA of 16.4 ± 13.3% compared with 8.6 ± 7.6% in MRC (p = 0.001). In the CA group, the absence of ventricular late gadolinium enhancement was associated with a greater improvement in absolute LVEF (19 ± 13% vs. 10 ± 11% in the late gadolinium enhancement-positive group; p = 0.04) and LVEF normalization in 19 patients (58%) versus 4 patients (18%) in the late gadolinium enhancement-positive group (p = 0.008) at 4.0 ± 0.9 years follow-up.CA is superior to MRC in improving LVEF in the long term in patients with atrial fibrillation and systolic heart failure. The greatest recovery in systolic function was demonstrated in the absence of ventricular fibrosis on cardiac magnetic resonance.

Aims Obesity is associated with higher electrical cardioversion (ECV) failure in persistent atrial fibrillation (PeAF). For ease-of-use, many centers prefer patches over paddles. We assessed the optimum modality and shock vector, as well as the safety and efficacy of the Manual Pressure Augmentation (MPA) technique. Methods Patients with obesity (BMI ≥ 30) and PeAF undergoing ECV using a biphasic defibrillator were randomized into one of four arms by modality (adhesive patches or handheld paddles) and shock vector (anteroposterior [AP] or anteroapical [AA]). If the first two shocks (100 and 200 J) failed, then patients received a 200-J shock using the alternative modality (patch or paddle). Shock vector remained unchanged. In an observational substudy, 20 patients with BMI of 35 or more, and who failed ECV at 200 J using both patches/paddles underwent a trial of MPA. Results In total, 125 patients were randomized between July 2016 and March 2018. First or second shock success was 43 of 63 (68.2%) for patches and 56 of 62 (90.3%) for paddles (P = 0.002). There were 20 crossovers from patches to paddles (12 of 20 third shock success with paddles) and six crossovers from paddles to patches (three of six third shock success with patches). Paddles successfully cardioverted 68 of 82 patients compared with 46 of 69 using patches (82.9% vs 66.7%; P = 0.02). Shock vector did not influence first or second shock success rates (82.0% AP vs 76.6% AA; P = 0.46). MPA was successful in 16 of 20 (80%) who failed in both (patches/paddles), with 360 J required in six of seven cases. Conclusion Routine use of adhesive patches at 200 J is inadequate in obesity. Strategies that improve success include the use of paddles, MPA, and escalation to 360 J.

Objectives This study sought to determine the impact of regular alcohol consumption on left atrial (LA) mechanical and reservoir function. Background Earlier studies suggest that regular alcohol intake is associated with increased atrial fibrillation (AF) and LA dilatation. Methods This study prospectively enrolled 160 patients with paroxysmal or persistent AF to undergo 3-T cardiac magnetic resonance (CMR) imaging in sinus rhythm. Patients self-reported alcohol consumption in standard drinks (∼12 g alcohol) per week over the preceding 12 months and were categorized into 4 groups: 1) lifelong nondrinkers; 2) mild drinkers (3 to 10 standard drinks/week); 3) moderate drinkers (11 to 20 standard drinks/week); 4) heavy drinkers (>20 standard drinks/week). Permanent AF and cardiomyopathy were excluded. On CMR, maximum LA volume (LAmax) and minimum LA volume (LAmin), global LA emptying fraction (LAEF) as (LAmax − LAmin) / LAmax, and LA reservoir function as (LAmax − LAmin) / LAmin were calculated. Results Regular alcohol consumption (mean 15.8 ± 6.9 standard drinks/week, n = 120) was associated with larger LA size (LA volume index 50 ± 13 ml/m2 vs. 43 ± 12 ml/m2; p = 0.005), reduction in LAEF (40 ± 14% vs. 52 ± 15%; p Conclusions In patients with AF, habitual alcohol consumption is associated with significantly increased LA size and atrial mechanical dysfunction compared with nondrinkers.

Objectives This study sought to determine if diffuse ventricular fibrosis improves in patients with atrial fibrillation (AF)-mediated cardiomyopathy following the restoration of sinus rhythm. Background AF coexists in 30% of heart failure (HF) patients and may be an underrecognized reversible cause of left ventricular systolic dysfunction. Myocardial fibrosis is the hallmark of adverse cardiac remodeling in HF, yet its reversibility is unclear. Methods Patients with persistent AF and an idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%) were randomized to catheter ablation (CA) or ongoing medical rate control as a pre-specified substudy of the CAMERA-MRI (Catheter Ablation versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction—an MRI-Guided Multi-centre Randomised Controlled Trial) trial. All patients had cardiac magnetic resonance imaging scans (including myocardial T1 time), serum B-type natriuretic peptide, 6-min walk tests, and Short Form-36 questionnaires performed at baseline and 6 months. Sixteen patients with no history of AF or left ventricular systolic dysfunction were enrolled as normal controls for T1 time. Results Thirty-six patients (18 in each treatment arm) were included in this substudy. Demographics, comorbidities, and myocardial T1 times were well matched at baseline. At 6 months, patients in the CA group had a significant reduction in myocardial T1 time from baseline compared with the medical rate control group (−124 ms; 95% confidence interval [CI]: −23 to −225 ms; p = 0.0176), although it remained higher than that of normal controls at 6 months (p = 0.0017). Improvements in myocardial T1 time with CA were associated with significant improvements in absolute LVEF (+12.5%; 95% CI: 5.9% to 19.0%; p = 0.0004), left ventricular end-systolic volume (p = 0.0019), and serum B-type natriuretic peptide (−216 ng/l; 95% CI: −23 to −225 ng/l; p = 0.0125). Conclusions The improvement in LVEF and reverse ventricular remodeling following successful CA of AF-mediated cardiomyopathy is accompanied by a regression of diffuse fibrosis. This suggests timely treatment of arrhythmia-mediated cardiomyopathy may minimize irreversible ventricular remodeling.

Objectives This study sought to characterize the biatrial substrate in heart failure (HF) and persistent atrial fibrillation (PeAF). Background Atrial fibrillation (AF) and HF frequently coexist; however, the contribution of HF to the biatrial substrate in PeAF is unclear. Methods Consecutive patients with PeAF and normal left ventricular (NLV) systolic function (left ventricular ejection fraction [LVEF] >55%) or idiopathic cardiomyopathy (LVEF ≤45%) undergoing AF ablation were enrolled. In AF, pulmonary vein (PV) cycle length (PVCL) was recorded via a multipolar catheter in each PV and in the left atrial appendage for 100 consecutive cycles. After electrical cardioversion, biatrial electroanatomic mapping was performed. Complex electrograms, voltage, scarring, and conduction velocity were assessed. Results Forty patients, 20 patients with HF (mean age: 62 ± 8.9 years; AF duration: 15 ± 11 months; LVEF: 33 ± 8.4%) and 20 with NLV (mean age: 59 ± 6.7 years; AF duration: 14 ± 9.1 months; p = 0.69; mean LVEF: 61 ± 3.6%; p Conclusions HF is associated with significantly reduced biatrial tissue voltage, fractionation, and prolongation of PVCL. Advanced biatrial remodeling may have implications for invasive and noninvasive rhythm control strategies in patients with AF and HF.