Sex-Related Differences in Atrial Remodeling in Patients With Atrial Fibrillation: Relationship to Ablation Outcomes

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 <0.001) and 300 ms (1.27±0.18 versus 1.57±0.18 mV, 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.

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P1010Association between left atrial fibrosis detected by cardiac magnetic resonance and endocardial electroanatomic mapping in the evaluation of the electrophysiological substrate in atrial fibrillation

EP Europace ◽

10.1093/europace/euaa162.068 ◽

2020 ◽

Vol 22 (Supplement_1) ◽

Author(s):

G Caixal ◽

F Alarcon ◽

M Nunez ◽

P Garre ◽

D Soto ◽

...

Keyword(s):

Atrial Fibrillation ◽

Magnetic Resonance ◽

Left Atrium ◽

Conduction Velocity ◽

Left Atrial ◽

Inverse Correlation ◽

High Density ◽

Atrial Fibrosis ◽

Reproducible Method ◽

Left Atrial Fibrosis

Abstract Background Atrial fibrillation (AF) is related to left atrial fibrosis, but its identification by late magnetic resonance imaging (LGE) with gadolinium (LGE) persists in controversy due to heterogeneous results in its correlation with the electroatomic map (EAM) and the difficulty of perform histological studies in humans. Purpose We try to examine the point-by-point association between high density EAM and LGE-MRI using an automatic and reproducible method. Methods A LGE-MRI was performed in 16 patients prior to ablation. Three different areas were established depending on the intensity of normalized enhancement for each patient according to their blood group with the image intensity ratio (IIR) (healthy <1.20, border area (BZ) ≥1.20 <1.32 and scar ≥1.32). The high density electroanatomic maps of the left atrium (LA) were projected onto the MRI, obtaining an automatic correlation point by point. Results The study obtained significant differences (p < 0.001) between voltage (mV) and CV (mm/ms) among healthy, BZ and scar areas, as well a significant inverse correlation (p < 0.001) between voltage and IIR (R=-0.39). It obtained too a significant correlation between CV and IIR (R=-0.24), but this showed a greater correlation in those patients who have the least dilated LA (p = 0.02). Conclusions LGE-MRI and EAM showed good correlation in delineating potential pathologic substrate in AF, but left atrium dilation could reduce the performance of the CMR in this task. Conduction velocity could be more sensitive than voltage and LGE-MRI to detect incipient substrate in AF. Voltage and conduction velocity values Area /IIR Velocity (mm/ms) Voltage (mV) I / <.20 1.036(0.913-1.158) 1.593(1.489-1.696) 2 / ≥1.20 and <1.32 0.722(0.590-0.850) 0.792 (0.649-0,935) 3 / ≥1.32 0.623(0.473-0,733) 0.444(0.245-0.642) Voltage and conduction velocity values in the three areas of the LGE-RMN. Abstract Figure. Correlation among voltage, VC and LA

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The Role of Atrial Fibrosis Detected by Delayed - Enhancement MRI in Atrial Fibrillation Ablation

Current Medical Imaging Formerly Current Medical Imaging Reviews ◽

10.2174/1573405614666180806130327 ◽

2020 ◽

Vol 16 (2) ◽

pp. 135-144 ◽

Cited By ~ 1

Author(s):

Zsuzsanna Kis ◽

Astrid Amanda Hendriks ◽

Taulant Muka ◽

Wichor M. Bramer ◽

Istvan Kovacs ◽

...

Keyword(s):

Atrial Fibrillation ◽

Imaging Modality ◽

Final Analysis ◽

Atrial Fibrosis ◽

Atrial Wall ◽

Af Ablation ◽

Left Atrial Wall ◽

Cmr Imaging

Introduction: Atrial Fibrillation (AF) is associated with remodeling of the atrial tissue, which leads to fibrosis that can contribute to the initiation and maintenance of AF. Delayed- Enhanced Cardiac Magnetic Resonance (DE-CMR) imaging for atrial wall fibrosis detection was used in several studies to guide AF ablation. The aim of present study was to systematically review the literature on the role of atrial fibrosis detected by DE-CMR imaging on AF ablation outcome. Methods: Eight bibliographic electronic databases were searched to identify all published relevant studies until 21st of March, 2016. Search of the scientific literature was performed for studies describing DE-CMR imaging on atrial fibrosis in AF patients underwent Pulmonary Vein Isolation (PVI). Results: Of the 763 citations reviewed for eligibility, 5 articles (enrolling a total of 1040 patients) were included into the final analysis. The overall recurrence of AF ranged from 24.4 - 40.9% with median follow-up of 324 to 540 days after PVI. With less than 5-10% fibrosis in the atrial wall there was a maximum of 10% recurrence of AF after ablation. With more than 35% fibrosis in the atrial wall there was 86% recurrence of AF after ablation. Conclusion: Our analysis suggests that more extensive left atrial wall fibrosis prior ablation predicts the higher arrhythmia recurrence rate after PVI. The DE-CMR imaging modality seems to be a useful method for identifying the ideal candidate for catheter ablation. Our findings encourage wider usage of DE-CMR in distinct AF patients in a pre-ablation setting.

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P1151Structural remodeling and conduction velocity dynamics in the human left atrium: relationship with reentrant mechanisms sustaining atrial tachycardia and atrial fibrillation

EP Europace ◽

10.1093/europace/euy015.637 ◽

2018 ◽

Vol 20 (suppl_1) ◽

pp. i219-i219

Author(s):

S Honarbakhsh ◽

R J Schilling ◽

M Orini ◽

R Providencia ◽

E Keating ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrium ◽

Conduction Velocity ◽

Atrial Tachycardia

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Abstract 18601: Impact of Right and Left Atrial Remodeling on Outcomes From Atrial Fibrillation Rotor Ablation

Circulation ◽

10.1161/circ.132.suppl_3.18601 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Amir Schricker ◽

Tina Baykaner ◽

Junaid Zaman ◽

Gautam Lalani ◽

Kenneth Hopper ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrial ◽

Structural Changes ◽

Unknown Etiology ◽

Atrial Remodeling ◽

Left Atrial Remodeling ◽

Single Procedure ◽

Clinical Indices ◽

The Right

Introduction: Targets for the ablation of atrial fibrillation (AF) are debated. In particular, recent studies questioning fractionated electrograms and lines has increased focus on AF substrates of rotors and focal impulses. These AF sources are seen in both atria, but have unknown etiology. We hypothesized that differential remodeling between the right atrium (RA), whose structural changes are largely undefined, and left atrium (LA) influence the distribution of AF sources and the outcomes from AF source ablation. Methods: In 60 patients at AF ablation (62±10 years, 60% persistent, 5% long-standing persistent), we compared size differences between RA and LA to the number of sources in each chamber and outcomes from AF source-guide ablation. We studied if a 64-pole basket differentially fit the LA or RA, judged by deformation of its splines by the atria (fig. A, B) over multiple cardiac cycles on fluoroscopy. Ablation targeted sources in both atria and was followed by PVI, with follow-up per guidelines. Results: Using baskets in both atria, 205 sources (LA 138; RA 67) were identified and ablated. Notably, the same basket in each patient was dynamically deformed by RA in 51 (85%) of cases but in the LA in only 39 (65%), indicating greater LA remodeling. The number of AF sources was higher in the presence of basket deformation of RA (n=174) than LA (n=130). LA deformation correlated with LVEF (p=0.05). Freedom from AF at 1 year was reduced in patients with no basket deformation (i.e. dilation) in LA (p=0.07) or RA (p=0.06). Notably, single procedure AF freedom was substantially lower in patients with differential remodeling (deformation in only 1 chamber) of 84% vs. 60% (fig C). Conclusions: Structural atrial remodeling influences the number of electrical rotors and focal sources in each chamber. A mismatch between right and left atrial remodeling predicts lower success from rotor ablation. These data also provide novel clinical indices of effective basket positioning.

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Thoracoscopic surgical atrial fibrillation ablation in patients with an extremely enlarged left atrium

Journal of Interventional Cardiac Electrophysiology ◽

10.1007/s10840-021-01056-1 ◽

2021 ◽

Author(s):

Jolien Neefs ◽

Robin Wesselink ◽

Nicoline W. E. van den Berg ◽

Jonas S. S. G. de Jong ◽

Femke R. Piersma ◽

...

Keyword(s):

Atrial Fibrillation ◽

Left Atrial ◽

Antiarrhythmic Drugs ◽

Primary Outcome ◽

Volume Index ◽

Substantial Part ◽

Atrial Tachyarrhythmia ◽

Af Ablation ◽

Male Patients

Abstract Purpose Efficacy of pulmonary vein isolation (PVI) for atrial fibrillation (AF) decreases as left atrial (LA) volume increases. However, surgical AF ablation with unknown efficacy is being performed in patients with a giant LA (GLA). We determined efficacy of thoracoscopic AF ablation in patients with compared to without a GLA. Methods Patients underwent thoracoscopic PVI with additional left atrial ablations lines (in persistent AF) and were prospectively followed up. GLA was defined as LA volume index (LAVI) ≥ 50 ml/m2. Follow-up was performed with ECGs and 24-h Holters every 3 months. After a 3-month blanking period, all antiarrhythmic drugs were discontinued. The primary outcome was freedom of any atrial tachyarrhythmia ≥ 30 s during 2 years of follow-up. Results At baseline, 68 (15.4%) patients had a GLA (LAVI: 56.7 [52.4–62.8] ml/m2), while 374 (84.6%) had a smaller LA (LAVI: 34.8 [29.2–41.3] ml/m2). GLA patients were older (61.9 ± 6.9 vs 59.4 ± 8.8 years, p = 0.02), more often diagnosed with persistent AF (76.5% vs 58.6%, p = 0.008). Sex was equally distributed (with approximately 25% females). GLA patients had more recurrences compared to non-GLA patients at 2-year follow-up (42.6% vs 57.2%, log rank p = 0.02). Freedom of AF was 69.0% in non-GLA paroxysmal AF patients compared to 43.8–49.3% in a combined group of GLA and/or persistent AF patients(log rank p < 0.001). Furthermore, freedom was 62.4% in non-GLA male patients, compared to 43.8–47.4 in a combined group of GLA and/or female sex(log rank p = 0.02). Conclusion Thoracoscopic AF ablation is an effective therapy in a substantial part of GLA patients. Thoracoscopic AF ablation may serve as a last resort treatment option in these patients.

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Termination of atrial fibrillation during pharmacological cardioversion in the goat requires inter-atrial synchronisation of conduction

EP Europace ◽

10.1093/europace/euab116.563 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

V Sobota ◽

A Van Hunnik ◽

S Zeemering ◽

G Gatta ◽

D Opacic ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Left Atrium ◽

Conduction Velocity ◽

Right Atrium ◽

Path Length ◽

Cycle Length ◽

Final Phase ◽

Periodic Activity ◽

Bachmann’S Bundle

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ITN Networks PersonalizeAF: Personalized Therapies for Atrial Fibrillation. A Translational Approach, No. 860974; CATCH ME: Characterizing Atrial fibrillation by Translating its Causes into Health Modifiers in the Elderly, No. 633196; MAESTRIA: Machine Learning and Artificial Intelligence for Early Detection of Stroke and Atrial Fibrillation, No. 965286; AFib-TrainNet: EU Training Network on Novel Targets and Methods in Atrial Fibrillation, No. 675351 Netherlands Heart Foundation: CVON2014-09, RACE V Reappraisal of Atrial Fibrillation: Interaction between hyperCoagulability, Electrical remodeling, and Vascular Destabilization in the Progression of Atrial Fibrillation Background Few studies report on mechanisms leading to termination of atrial fibrillation (AF). Purpose To characterise electrophysiological parameters and conduction patterns during the transition from AF to sinus rhythm under various conditions of AF termination. Methods A retrospective evaluation of 6 goat studies was performed. AF was maintained for 3-4 weeks in 29 animals. Four animals were in SR. Unipolar electrograms were acquired with one 249-electrode array/atrium. Pharmacological termination of AF was evoked by various drugs; AP14145 (n = 5), PA6 (n = 7), XAF-1407 (n = 9) vernakalant (n = 8). In animals with sinus rhythm, AF was acutely induced and terminated spontaneously. Baseline AF and ≤3 recordings of the last 10 seconds preceding AF termination were analysed. Intervals with temporal continuous and periodic activity were distinguished in the recordings. AF cycle length (AFCL), conduction velocity and path length were determined for each interval. Results In total, 85 AF terminations were recorded. Switches between temporal continuous and periodic activity were seen frequently during AF. However, termination of AF was always preceded by a phase of periodic activity (PA). The final phase of PA persisted for a median number of 21 [IQR 10-28] cycles in the left atrium and somewhat shorter in the right atrium, Table 1. This final phase of PA was accompanied by a profound bi-atrial increase of AFCL, conduction velocity and path length and a disappearance of inter-atrial cycle length differences. Equipotent changes were not observed in the preceding PAs. During the final AF beats, the number of wave fronts were low, 1 or 2. Interestingly, 92% of the patterns during the last beats of AF involved the Bachmann’s bundle as main source of atrial conduction. Conclusion AF termination is preceded by an increased organisation of fibrillatory conduction, associated with abrupt prolongation of the path length. Propagation in atrial free walls regularly originated from the Bachmann’s bundle. These findings suggest that AF termination was not a random process but follows common spatiotemporal patterns. Final period of temporal organisation Left atrium Right atrium Final PA start Final PA end Final PA start Final PA end Af cycle length (ms) 163 ± 37 204 ± 50* 146 ± 44 207 ± 49* Conduction velocity (cm/s) 77 ± 15 96 ± 25* 83 ± 20 103 ± 24* Path Length (cm) 12.2 ± 2.7 19.3 ± 6.3* 12.0 ± 4.1 21.2 ± 6.4* Length of final periodic activity (beats) NA 21 [IQR 10-28] NA 15 [IQR 10- 25] Electrophysiological changes during the final period periodic activity (PA). Wilcoxon signed rank test. *p <0.05NA= not available

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Abstract 4649: A Radiofrequency HOT Balloon Catheter for Isolating the Posterior Left Atrium Including All the Pulmonary Veins in the Treatment of Atrial Fibrillation: Feasibility and Safety of a New Approach

Circulation ◽

10.1161/circ.118.suppl_18.s_924-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Hiroshi Sohara ◽

Shutaro Satake ◽

Hiroshi Takeda ◽

Hideki Ueno ◽

Toshimichi Oda

Keyword(s):

Atrial Fibrillation ◽

Left Atrium ◽

Phrenic Nerve ◽

Pulmonary Veins ◽

Balloon Catheter ◽

Holter Monitoring ◽

Phrenic Nerve Palsy ◽

Total Procedure Time ◽

Successful Isolation

Atrial fibrillation (AF) is originated from mostly from pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (PLA). The present study was designed to evaluate the usefulness of a radiofrequency HOT balloon catheter (RBC) for isolation of the PLA including all PVs en masse in the patients with AF. In a total of 96 patients (75 men and 21 women; mean age 64±8 years old) with drug-resistant paroxysmal (n=63) and persistent AF(n=33), PLA including all PVs were ablated and isolated using RBC. Dragging the balloon, contiguous lesions at the roof between the superior PVs were first created, then each antrum of all PVs were ablated, and finally, contiguous lesions at the PLA between the both inferior PVs were made, while we performed monitoring esophagus temperature and phrenic nerve pacing. Electro-anatomical bipolar voltage amplitude mapping (CARTO) of the LA-PVs was performed to determine the extent of this electrical isolation after all procedure. Successful isolation of the PLA including all PVs was achieved in all of 96 cases with elimination of all the PLA and PV potentials. The mean total procedure time 133 ± 31 minutes including 32±9 minutes fluoroscopy time. Recurrences of AF were diagnosed by Holter monitoring, mobile electrocardiogram. After first session, eighty- seven (59 paroxysmal, 28 persistent) of 96 patients were free from AF without anti-arrhythmic drugs and the remaining patients could maintain sinus rhythm with anti-arrhythmic drugs except two cases with LA flutter during 11.0±4.1 months follow-up. No major complications such as cerebral embolism, PV stenosis, or phrenic nerve palsy, and LA-esophageal fistula were observed. Complete isolation of the PLA including all PVs using a RBC, is useful for the treatment of both paroxysmal and persistent AF without severe complication.

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Abstract 16237: Zero Fluoroscopy Ablation of Atrial Fibrillation: A Safety and Feasibility Study

Circulation ◽

10.1161/circ.130.suppl_2.16237 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Luigi Di Biase ◽

Rodney Horton ◽

Chintan Trivedi ◽

Prasant Mohanty ◽

Sanghamitra Mohanty ◽

...

Keyword(s):

Atrial Fibrillation ◽

Catheter Ablation ◽

Pulmonary Veins ◽

Radiation Risk ◽

Control Group ◽

Short Term ◽

Af Ablation ◽

And Control ◽

Zero Fluoroscopy

Introduction: Radiofrequency catheter ablation of atrial fibrillation is performed under fluoroscopic guidance and therefore carries radiation risk exposure for the both the patient and the operator. Three-dimensional mapping systems and newer technologies to allow non-fluoroscopic catheter visualization together with intracardiac echo have reduced but not abolished the fluoroscopy exposure. We aim to demonstrate the feasibility, the safety and the efficacy of catheter ablation for atrial fibrillation without the use of fluoroscopy. Methods: A totally fluoro-less approach was developed for AF ablation at our Institution. 94 consecutive AF patients underwent zero fluoroscopy catheter ablation for atrial fibrillation. In the zero fluoroscopy cases, the fluoroscopy arm was kept far away from the patient table. Access including double trans-septal, mapping with the Carto 3 system and ablation were all performed without fluoroscopy with the use of ICE and the Carto 3 system. These 94 patients were compared with 94 control patients matched for age, sex and type of AF who underwent AF ablation by the same operator with the use of fluoroscopy. Results: Baseline characteristics were similar between fluoroless (N=94, Age=64.5 ± 10.1, 75.5% male, 48% paroxysmal) and control (N=94, Age=65.1 ± 9.9, 72.3% male, 50% paroxysmal) group. Non-PV triggers were detected and ablated in 51 (54.3%) and 56 (59.6%) patients in fluoroless and control group respectively (p=0.5). Average fluoro time in control group was 10.1 ± 4.7 minutes. Procedure duration was comparable (120.4 ± 25.8 vs. 122.2 ± 28.7, p =0.6). After the short term median follow-up of 4.5 (4 – 6.5) months, 10 (10.6 %) patients in flourless and 9 (9.6%) patients in control group experienced recurrences (p=0.8).One pericardial effusion requiring pericardiocenteis occurred in the fluoroless group. Conclusions: Our series show that zero fluoroscopy ablation of atrial fibrillation with the use of newer technologies is feasible, safe and efficacious at the short term follow up. Importantly in our series the double transeptal was performed without fluoroscopy and the ablation was not limited to the pulmonary veins only but included ablation of the posterior wall, the coronary sinus and the left atrial appendage.

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Abstract 3175: Plasma Tansforming Growth Factor Beta as a Biochemical Marker to Predict the Recurrence of Atrial Fibrillation After Surgical Maze

Circulation ◽

10.1161/circ.116.suppl_16.ii_713-a ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Young Keun On ◽

Dae-Hee Shin ◽

Jin-Oh Choi ◽

Yong Hwan Park ◽

Sang Yeub Lee ◽

...

Keyword(s):

Atrial Fibrillation ◽

Messenger Rna ◽

Left Atrial ◽

Multiple Logistic Regression Analysis ◽

Internal Standard ◽

Maze Procedure ◽

Atrial Remodeling ◽

Rt Pcr ◽

Heart Operation

BACKGROUND Atrial remodeling leads to perpetuation of atrial fibrillation (AF). Structural remodeling in the form of fibrosis alters the substrate. The surgical Maze procedure was developed as a surgical treatment of AF. Our purpose was to evaluate the role of plasma NT-proBNP, hsCRP, TIMP-1(Tissue inhibitors of MetalloProteinase-1), TGF-β, MMP-3(Matrix MetalloProteinase-3), and pro-MMP-1in predicting the recurrence of AF after surgical Maze procedure. And we also evaluated the association of expression of CTGF, TGF-β, BNP, ANP, collagen-1α, and collagen-3α in LA with the recurrence of AF after surgical Maze procedure. METHODS Preoperative plasma NT-proBNP, hsCRP, TIMP, TGF-β, MMP-3, and pro-MMP-1 levels were measured in consecutive 86 patients (age 54±12 yrs) who underwent the open heart operation for valvular heart disease and surgical Maze procedure for AF. Moreover, we performed molecular examinations of CTGF, TGF-β, BNP, ANP, Collagen-1α, Collagen-3α in the resected left atrial tissues. Symptomatic AF documented by ECG or an episode of AF revealed at follow-up holter monitoring were considered atrial fibrillation recurrences. RESULTS At 1-year follow-up, 10 among 86 patients had persistence of AF. Patients with AF persistence had higher plasma TGF-β levels than the patients with sinus rhythm (0.44 ± 0.29 vs 0.32 ± 0.15 ng/ml) . Patients with AF persistence had higher messenger RNA expressions of Collagen-3α (0.21 ± 0.20 vs 0.12 ± 0.12, compared with internal standard GAPDH by RT-PCR) and lower messenger RNA expressions of ANP (0.31 ± 0.16 vs 0.60 ± 0.76, compared with internal standard GAPDH by RT-PCR ) in left atrial tissues. Multiple logistic regression analysis revealed that plasma TGF-β was independently associated with postoperative persistence of atrial fibrillation at 1 year follow-up after surgical Maze procedure. CONCLUSIONS Advanced atrial degenerative change might result in a decrease of atrial ANP secretion. Cardiac fibrosis might be a determinant of myocardial heterogeneity and the persistence of AF. Plasma TGF-β could predict the persistence of AF at 1 year follow-up after surgical Maze procedure.

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P3778Long-term outcome of non-pharmacologial treatment of atrial fibrillation in hypertrophic cardiomyopathy: a large single-centre experience

European Heart Journal ◽

10.1093/eurheartj/ehz745.0627 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

L Dinshaw ◽

M Lemoine ◽

J Hartmann ◽

B Schaeffer ◽

N Klatt ◽

...

Keyword(s):

Atrial Fibrillation ◽

Catheter Ablation ◽

Left Atrial ◽

High Density ◽

Term Outcome ◽

Long Term Outcome ◽

Density Mapping ◽

Ablation Success

Abstract Introduction Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) and is generally associated with a significant deterioration of clinical status. Non-pharmacological treatment such as surgical and catheter ablation has become an established therapy for symptomatic AF but in patients with HCM often having a chronically increased left atrial pressure and extensive atrial cardiomyopathy the long-term outcome is uncertain. Purpose The present study aimed to analyse the long-term outcome of AF ablation in HCM and the mechanism of recurrent atrial arrhythmias using high-density mapping systems. Methods A total of 65 patients (age 64.5±9.9 years, 42 (64.6%) male) with HCM undergoing AF ablation for symptomatic AF were included in our study. The ablation strategy for catheter ablation included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines if appropriate. In patients with suspected atrial tachycardia (AT) high-density activation and substrate mapping were performed. A surgical ablation at the time of an operative myectomy for left ventricular outflow tract obstruction was performed in 8 (12.3%) patients. The outcome was analysed using clinical assessment, Holter ECG and continuous rhythm monitoring of cardiac implantable electric devices. Results Paroxysmal AF was present in 27 (41.6%), persistent AF in 37 (56.9%) and primary AT in 1 (1.5%) patients. The mean left atrial diameter was 54.1±12.5 ml. In 11 (16.9%) patients with AT high-density mapping was used to characterize the mechanism of the ongoing tachycardia. After 1.9±1.2 ablation procedures and a follow-up of 48.5±37.2 months, ablation success was demonstrated in 58.9% of patients. The success rate for paroxysmal and persistent AF was 70.0% and 55.8%, respectively (p=0.023). Of those patients with AT high-density mapping guided ablation was successful in 44.4% of patients. The LA diameter of patients with a successful ablation was smaller (52.2 vs. 58.1 mm; p=0.003). Conclusion Non-pharmacological treatment of AF in HCM is effective during long-term follow-up. Paroxysmal AF and a smaller LA diameter are favourable for successful ablation. In patients with complex AT the use of high-density mapping can guide ablation resulting in further ablation success in a reasonable number of patients.

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