Pulmonary Vein Isolation For Atrial Fibrillation Research Articles

Catheter ablation of atrial fibrillation shows pulmonary vein dependent effect on the signal-averaged P-wave morphology

Abstract Background and Aims Cryoballoon ablation of atrial fibrillation alters a significant amount of vital myocardium that contributes to its electrical activity. However, the impact of pulmonary vein isolation (PVI) on P-wave morphology is unclear. The aim of this investigation was to quantify whether the contribution of the left or right pulmonary veins (PVs) is greater using means of signal-averaged P-wave analysis. Methods Unfiltered high-resolution (2000 samples/second) ECGs were obtained for 5 minutes both pre- and post-isolation of the left and right PVs, with 12 standard and 10 additional leads (x01-x10). Additional lead positions were determined in prior studies for optimal detection of atrial electrical activity not captured by standard leads. Signal-averaged ECGs were computed and analyzed using bespoke software in Matlab. Statistical significance was assessed using a two-tailed paired t-test. A total of 69 participants were screened for the study. For the analysis, 64 participants with sinus rhythm in all ECG recordings were eligible. Results Significant postablation changes for various ECG parameters across different lead combinations were found (Table 1). On average, after ablation of the left pulmonary veins (LPVs), there was a reduction in P-wave terminal force (3.07±2.05 mV*ms vs. 2.84±1.88 mV*ms, p = 0.044), P-wave complexity (2.02±0.64 vs. 1.90±0.57, p = 0.047), and sample entropy (0.210±0.039 au vs. 0.197±0.031 au, p < 0.001), whereas P-wave duration (148.24 ms vs. 153.23 ms, p < 0.001) and PQ time (200.41 ms vs. 205.43 ms, p < 0.001) prolonged. However, after ablation of the right pulmonary veins (RPVs), sample entropy decreased (0.196±0.031 au vs. 0.190 ±0.027 au, p = 0.049) and amplitude increased (0.087±0.024 mV vs. 0.091±0.024 mV, p = 0.002). Conclusion PVI in atrial fibrillation has a significant effect on signal-averaged P-wave. These effects are more pronounced after ablation of the LPVs than the RPVs. Parameters such as PWTF, PWC and SaE demonstrate potential to assess the effect of catheter ablation and may serve as a potential indicator for a successful procedural outcome.

Risk of atrial arrhythmias in patients with ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy

BackgroundIn arrhythmogenic right ventricular cardiomyopathy (ARVC), risk of atrial arrhythmias (AAs) persists after ventricular tachycardia (VT) ablation. ObjectiveThe purpose of this study was to determine the type, prevalence, outcome, and risk correlates of AA in ARVC in patients undergoing VT ablation. MethodsProspectively collected procedural and clinical data on ARVC patients undergoing VT ablation were analyzed. Risk score for typical atrial flutter was determined from univariate logistic regression analysis. ResultsOf 119 consecutive patients with ARVC and VT ablation, 40 (34%) had AA: atrial fibrillation (AF) in 31, typical isthmus-dependent atrial flutter (AFL) in 27, and atrial tachycardia/atypical flutter (AT) in 10. Seventeen patients (43%) with AA experienced inappropriate defibrillator therapy, with 15 patients experiencing shocks. Ablation was performed for typical AFL in 21 (53%), AT in 5 (13%), and pulmonary vein isolation for AF in 4 (10%) patients and prevented AA in 78% and all AFL during additional mean follow-up of 65 months. Risk score for typical flutter included age >40 years (1 point), ≥moderate right ventricular dysfunction (2 points), ≥moderate tricuspid regurgitation (2 points), ≥moderate right atrial dilation (2 points), and right ventricular volume >250 cc (3points), with score >4 identifying 50% prevalence of typical flutter. ConclusionAAs are common in patients with ARVC and VT, can result in inappropriate implantable cardioverter-defibrillator shocks, and typically are controlled with atrial ablation. A risk score can be used to identify patients at high risk for typical AFL who may be considered for isthmus ablation at the time of VT ablation.

External validation of the Antwerp score: a novel score for predicting responders to catheter ablation of atrial fibrillation in patients with depressed left ventricular function

Abstract Introduction Little exists to identify patients with heart failure (HF) and atrial fibrillation (AF), who will benefit from pulmonary vein isolation (PVI). The Antwerp score was proposed as a new prediction model to identify patients with recovery left ventricular ejection fraction (LVEF) after PVI for AF. Purpose To externally validate the Antwerp score in a large cohort of patients undergoing PVI. Methods Patients with reduced LVEF (< 50%) scheduled to undergo PVI at our hospital were retrospectively analyzed. These were then classified as responders or non-responders to PVI according to the "Universal definition of HF". For each patient, the Antwerp score was calculated, and the performance of the score in predicting LVEF recovery after PVI was evaluated using receiver operating characteristic (ROC) curves and calibration plots. Results Between May 2010 and January 2022, 1665 patients underwent CA for AF at our institution. Of these, 208 patients (median age 63 [IQR 54-69] years, 19% women) had reduced LVEF at presentation and were included in the final analysis (27% with paroxysmal and 73% with persistent AF). The median LVEF at baseline was 43% [IQR 38-46]. At 30 [IQR 20-34] months follow-up after the index procedure, 161 patients (77%) were responders, and 47 patients (23%) were non-responders. The median time to LVEF recovery in responders was 8 [IQR 3-22] months. Between responders and non-responders, differences in AF type were not significant (p = 0.99), while QRS width, absence of known HF etiology and LAVI were significant (p<0.001, p<0.001 and p=0.03). After adjusting for difference in baseline characteristics and procedural outcomes between responders and non-responders, only a QRS duration<120 ms (p=0.002) and absence of known etiology (p<0.001) remained statistically significant with LVEF recovery (Figure). The Antwerp score had an area under the curve (AUC) of 0.75 (95% CI 0.67-0.83). A model containing QRS<120 ms and absence of known etiology performed similarly to the complete Antwerp model (Likelihood Ratio p=0.77). Conclusion The Antwerp score has a moderate ability to identify patients with the recovery of LVEF after PVI in an external population, showing modest rule-in and rule-out capabilities. QRS width and absence of known HF etiology were confirmed as excellent predictors of LVEF recovery.Figure

Abstract 13542: Electrical Delay, LA Electromechanical Delay, and LA Volume Contribute to Increased LA Stiffness in Relatively Elderly Patients With Pulmonary Vein Isolation for Atrial Fibrillation

Background: Atrial dysfunction occurs after pulmonary vein isolation (PVI) for atrial fibrillation (AF), and some reports suggest that electrical conduction delay (ECD) via the Bachmann bundle could be a contributing factor. However, the relationship between ECD in the atria and LA function after PVI remains unclear. The LA reservoir strain (LARS) by speckle-tracking echocardiography (STE) is used to assess LA booster function, with a decrease indicating increased LA stiffness. Purpose: We aim to investigate ECD, LA electromechanical delay (LAEMD), and LA function in patients after PVI for AF. Methods: This single-center retrospective study included 74 patients (Mean age at 70.4 ± 9.1 years, 44 males, left ventricular ejection fraction (LVEF): 62.9 ± 6.8 %, LA volume index: LAVI 39.0 ± 10.8 ml/m 2 ) who were in sinus rhythm at the echocardiographic examination. ECD on the ECG was defined as the presence of biphasic P waves, which were classified into those not observed (group A; n=42), those observed only in III lead (group B; n=23), and those observed in all lower wall leads (II, III, aVF) (group C; n=9). LAEMD was defined as the time interval between the top of the R wave on the ECG and the start of the late diastolic wave (a') on the tissue doppler imaging, and the lateral (a' lateral) and septum (a' septum) time differences (a’ sep-lat time) were calculated. To evaluate the LA function, two-dimensional STE was analyzed. Results: Mean observation period was 19.2 months after PVI. Groups B and C showed significant differences in a' sep-lat time compared to group A. LARS was markedly reduced in all groups (average: 19.0 ± 6.3). LARS and LAVI showed a significant difference between groups A and C. Multivariate analysis of factors leading to LARS showed correlations with a', E/e'. Conclusion: These results suggest that in relatively elderly post-PVI AF patients with preserved LVEF, the ECD and LAEMD as well as LAVI may affect LA function long after PVI and contribute to increased LA stiffness.

Impact of general anesthesia on ablation catheter stability during pulmonary vein isolation based on a novel measurement approach

Catheter ablation for atrial fibrillation (AF) during pulmonary vein isolation (PVI) is performed under general anesthesia (GA) or conscious sedation (CS). GA during PVI may improve treatment outcomes by improving catheter stability. However, the magnitude of GA-derived catheter stability compared with that of CS is unclear. We directly assessed catheter movement and determined the impact of GA compared with that of CS on ablation catheter stability during PVI. Patients who underwent initial ablation using the EnSite Precision™ mapping system were recruited and divided into two groups (GA and CS groups). The two groups were compared for ablation catheter stability during PVI based on the distance traveled by the catheter distal tip per second, clinical periprocedural characteristics, and periprocedural complications. Among 69 consecutively admitted patients, data of 30 patients (17 in the GA group and 13 in the CS group) and the distance traveled per second by the catheter on 148,976 points/patient were evaluated. The GA group had a significantly smaller catheter tip travel distance than the CS group (0.92 [0.82‒1.16] vs. 1.25 [1.14‒1.38], p = 0.01). Therefore, GA during PVI for AF provides greater catheter stability than CS and will contribute to more accessible and safer PVI procedures.

Reduction in atrial and ventricular electrical heterogeneity following pulmonary vein isolation in patients with atrial fibrillation

Pulmonary vein isolation (PVI) modulates the intrinsic cardiac autonomic nervous system and reduces atrial fibrillation (AF) recurrence. In this retrospective analysis, we investigated the impact of PVI on ECG interlead P-wave, R-wave, and T-wave heterogeneity (PWH, RWH, TWH) in 45 patients in sinus rhythm undergoing clinically indicated PVI for AF. We measured PWH as a marker of atrial electrical dispersion and AF susceptibility and RWH and TWH as markers of ventricular arrhythmia risk along with standard ECG measures. PVI acutely (16 ± 8.9h) reduced PWH by 20.7% (from 31 ± 1.9 to 25 ± 1.6µV, p < 0.001) and TWH by 27% (from 111 ± 7.8 to 81 ± 6.5µV, p < 0.001). RWH was unchanged after PVI (p = 0.068). In a subgroup of 20 patients with longer follow-up (mean = 47 ± 3.7days after PVI), PWH remained low (25 ± 1.7µV, p = 0.01), but TWH partially returned to the pre-ablation level (to 93 ± 10.2, p = 0.16). In three individuals with early recurrence of atrial arrhythmia in the first 3months after ablation, PWH increased acutely by 8.5%, while in patients without early recurrence, PWH decreased acutely by 22.3% (p = 0.048). PWH was superior to other contemporary P-wave metrics including P-wave axis, dispersion, and duration in predicting early AF recurrence. The rapid time course of decreased PWH and TWH after PVI suggests a beneficial influence likely mediated via ablation of the intrinsic cardiac nervous system. Acute responses of PWH and TWH to PVI suggest a favorable dual effect on atrial and ventricular electrical stability and could be used to track individual patients' electrical heterogeneity profile.

Comparison of various late gadolinium enhancement magnetic resonance imaging methods to high-definition voltage and activation mapping for detection of atrial cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background/Introduction Atrial cardiomyopathy (ACM) is associated with the progression from paroxysmal through persistent to permanent atrial fibrillation (AF) and increased arrhythmia recurrence rates after pulmonary vein isolation (PVI). Purpose We compare the most common left atrial (LA) late gadolinium enhancement magnetic resonance imaging (LGE-MRI)-methods (Utah-method and image-intensity-ratio (IIR)-methods) and endocardial voltage mapping for ACM-detection and outcome prediction after PVI for AF. Methods In this prospective study, 37 ablation-naive patients (66±9 years, 84% male) with persistent AF were included and electrically cardioverted into sinus rhythm. Subsequently, they underwent LA-LGE-MRI and high-definition voltage and activation mapping (2129±484 sites) in sinus rhythm prior to PVI. MRI-post-processing-analyses were performed by two independent expert laboratories (Marrek for the Utah segmentation as describers of this methodology and Adas 3D medical as developers of the Adas software for the IIR-methods) which were blinded to any clinical data. Arrhythmia recurrence was recorded within 12 months following PVI. Results The global ACM-extent was highly variable: median LA low-voltage substrate (LA-LVS) was 12.9% at &amp;lt;1.0mV and 2.7% at &amp;lt;0.5mV; median LA-LGE-extent using the Utah-method was 18.3% and 0.03%-93.1% using the IIR-methods. LA activation time was significantly correlated with LA-LVS (r=0.76 at &amp;lt;0.5mV and r=0.82 at &amp;lt;1.0mV, both p&amp;lt;0.0001), but not with LA-LGE-extent. The highest regional matching between LA-LVS &amp;lt;0.5mV and LA-LGE was found for the anterior wall in 57% of patients using the Utah-method and in 59% using IIR 1.20. The corresponding values for the posterior wall were 19% and 38%, respectively. Arrhythmia recurrence occurred in 15 (41%) patients. Freedom from arrhythmia was significantly lower in those with relevant LA-LVS (≥2cm2 at 0.5mV) but not in those with relevant LGE (Utah-stages III&amp;IV): 43% versus 81%, p=0.009 and 50% versus 67%, p=0.338, respectively. Furthermore, relevant LA-LVS was the only predictor for arrhythmia recurrence in multivariate regression analysis. Conclusion The different LA-LGE-MRI methods have large dicrepancies regarding extent and distribution of ACM and are different to the extent and regional distribution of LA-LVS as assessed in endocardial high-definition voltage mapping in sinus rhythm. Further improvements of the LA-LGE-MRI-methods are required to enable correct diagnosis of ACM and for future evaluation of MRI-guided ablation protocols.

Unique left pulmonary vein isolation in straight common trunk based on longitudinal conduction of left lateral ridge.

A left common pulmonary vein (LCPV) is the most common anatomical variation in the pulmonary vein (PV) and often influences strategies of PV isolation for atrial fibrillation (AF). Our objective was to elucidate the electrical properties of the specific shape of LCPV and to apply it to an ablation procedure. We investigated consecutive 12 out of 204 paroxysmal AF patients who had the shape of a straight common trunk in LCPV defined by the formation of a single conduit with parallel cranial and caudal walls after the coalescence of superior and inferior PVs on the distal side. The distance between the top of the bifurcation of LPVs and the level coinciding with the middle of the anterior wall of LCPV (left lateral ridge: LLR) was more than 10mm in all the patients. The activation pattern of the LLR showed longitudinal conduction without outside connections. All the LCPV except one were successfully isolated without ablating the LLR (C-shape ablation). Only one patient had AF recurrence during the follow-up period. The LLR in LCPV with a straight common trunk has longitudinal conduction without outside connections, which permits the isolation of LCPV without ablating LLR.

Comparison of various late gadolinium enhancement magnetic resonance imaging methods with high-definition voltage and activation mapping for detection of atrial cardiomyopathy.

Atrial cardiomyopathy (ACM) is associated with increased arrhythmia recurrence rates after pulmonary vein isolation (PVI). We compare the most common left atrial (LA) late gadolinium enhancement magnetic resonance imaging (LGE-MRI)-methods [Utah-method and image intensity ratio (IIR)-methods] and endocardial voltage mapping for ACM-detection and outcome prediction after PVI for atrial fibrillation (AF). In this prospective observational study, 37 ablation-naive patients (66 ± 9 years, 84% male) with persistent AF underwent LA-LGE-MRI and high-definition voltage and activation mapping (2129 ± 484 sites) in sinus rhythm prior to PVI. The MRI-post-processing-analyses were performed by two independent expert laboratories. Arrhythmia recurrence was recorded within 12 months following PVI. The global ACM-extent was highly variable: median LA low-voltage substrate (LA-LVS) was 12.9% at <1.0 mV and 2.7% at <0.5 mV; median LA-LGE-extent using the Utah-method was 18.3% and 0.03-93.1% using the IIR-methods. The LA activation time was significantly correlated with LA-LVS (r = 0.76 at <0.5 mV and r = 0.82 at <1.0 mV, both P < 0.0001), but not with LA-LGE-extent. The highest regional matching between LA-LVS <0.5 mV and LA-LGE was found for the anterior wall in 57% of patients using the Utah-method and in 59% using IIR 1.20. The corresponding values for the posterior wall were 19% and 38%, respectively. Arrhythmia recurrence occurred in 15(41%) patients. Freedom from arrhythmia was significantly lower in those with LA-LVS ≥2 cm2 at 0.5 mV but not in those with LGE ≥20% (Utah-stages III and IV): 43% vs. 81%, P = 0.009 and 50% vs. 67%, P = 0.338, respectively. Comparison of the most common LA-LGE-MRI methods and endocardial voltage mapping revealed large discrepancies in global and regional ACM-extent.

Abstract 10794: Adenosine Induced Dormant Pulmonary Vein Reconnection Predicts Recurrent Atrial Fibrillation After Pulmonary Vein Isolation: Systematic Review and Meta-Analysis

Introduction: Adenosine can be used to reveal dormant pulmonary vein (PV) conduction following pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF). Hypothesis: We performed a systematic review and meta-analysis to assess the impact of adenosine administration in patients undergoing PVI for AF. Methods: We searched PubMed, Medline, Embase, Ovid, and Cochrane for studies that reported freedom from AF during follow-up compared between those without reconnection and those with reconnection (requiring further targeted ablation). Statistical analysis was performed using meta-package for R version 4.0 and Rstudio version 1.2. Results: A total of 20 eligible studies (14 prospective, 3 retrospective, 3 randomized) consisting of 3,595 patients (Reconnection group - 1,228 and No Reconnection group - 2,367) were included in the meta-analysis. The follow-up period ranged from 6.1 months to 36 months. The freedom from AF in patients with PV reconnection was 62.45% compared to 68.10% of patients without PV reconnection. There was significant heterogeneity between studies (I2 = 68%; p &lt; 0.001). Random-effects meta-analysis showed significantly higher freedom from AF in patients with no identified reconnection than those with identified reconnection (RR 0.89; 95% CI 0.80 - 0.99; p = 0.03). Conclusions: Adenosine-guided dormant conduction was associated with higher AF recurrence despite further ablation, but there was substantial heterogeneity between trials. Future research should be directed to improved techniques, and optimal methodology, including adenosine dosage and wait time between PVI and adenosine administration.

Pulmonary vein isolation for AF: does technique influence outcome?

Abstract Funding Acknowledgements Type of funding sources: None. Background Over the last 20 years various techniques have been developed striving for safer and more durable pulmonary vein isolation (PVI). The three most commonly used tools are pulmonary vein ablation catheter (PVAC) and cryoballoon (‘single-shot’ techniques), and point-by-point (PBP) radiofrequency ablation using 3D electroanatomical mapping (EAM). Objective Evaluate the safety and efficacy of the different techniques in an unselected population undergoing de-novo ablation for persistent or paroxysmal atrial fibrillation (AF) at a single high-throughput centre. Method Retrospective, single-centre study of consecutive AF ablations between March 2017 and April 2018. Demographic, procedural and outcome data were analysed. Results Over the study period 329 first-time PVI procedures were performed. 37.4% were performed using PBP, 39.8% using cryoballoon and 22.8% using PVAC. There was no significant difference in age or sex between different ablation technique groups. 238 procedures were performed for paroxysmal AF and 91 for persistent AF. A higher proportion of the persistent cases were performed using point-by-point techniques compared to paroxysmal cases (58.2% vs 29.0%, p &amp;lt; 0.05). Procedural times were significantly longer in the group undergoing PBP ablation compared to cryoballoon or PVAC. However, there was no statistically significant difference in 12-month freedom from symptomatic AF or procedural complications between the groups. Conclusions PBP, PVAC and cryoballoon AF ablation all appeared equally efficacious in an unselected population, though PVAC and cryoballoon procedures were shorter. All procedures were associated with a low adverse event rate. Prospective examination is required to substantiate this finding. Table 1CARTOn= 123Cryoballoonn= 131PVACn = 75p-valueAge/years61.7 ± 9.259.5 ± 10.661.7 ± 9.70.14Male92 (74.8)88 (67.2)49 (61.3)0.80Paroxysmal AF70 (56.9)106 (78.6)62 (82.7)0.14Cardiovascular risk factors Hypertension Diabetes Ischaemic heart disease Cerebrovascular disease Heart failure Dyslipidaemia73 (59.3)23 (18.7)40 (32.5)2 (1.6)0 (0) 12 (9.8)79 (60.3)19 (14.5)45 (34.4)0 (0)1 (0.8)16 (12.2)43 (57.3)16 (21.3)22 (29.3)1 (1.3)0 (0)10 (13.3) 0.58 0.24 0.62 - - 0.71Left atrial diameter/cm4.2 ± 0.74.1 ± 0.73.9 ± 1.00.69Procedure time/mins191.3 ± 39126.7 ± 24117.4 ± 30&amp;lt;0.056 month success Paroxysmal Persistent50/66 (75.8)32/51 (62.7)78/103 (75.7)18/24 (75.0)48/61 (78.6)10/12 (83.3) 0.99 0.80Complications9 (7.3)3 (2.3)1 (1.3)0.07Patient demographics, procedural characteristics and outcomes for Carto, cryoballoon and PVAC cases. Values presented as mean ± SD or n (%)Abstract Figure. Time to arrhythmia recurrence

Unipolar electrogram-based voltage mapping with far-field cancellation to improve detection of abnormal atrial substrate during atrial fibrillation.

An important substrate for atrial fibrillation (AF) is fibrotic atrial myopathy. Identifying low voltage, myopathic regions during AF using traditional bipolar voltage mapping is limited by the directional dependency of wave propagation. Our objective was to evaluate directionally independent unipolar voltage mapping, but with far-field cancellation, to identify low-voltage regions during AF. In 12 patients undergoing pulmonary vein isolation for AF, high-resolution voltage mapping was performed in the left atrium during sinus rhythm and AF using a roving 20-pole circular catheter. Bipolar electrograms (EGMs) (Bi) < 0.5 mV in sinus rhythm identified low-voltage regions. During AF, bipolar voltage and unipolar voltage maps were created, the latter with (uni-res) and without (uni-orig) far-field cancellation using a novel, validated least-squares algorithm. Uni-res voltage was ~25% lower than uni-orig for both low voltage and normal atrial regions. Far-field EGM had a dominant frequency (DF) of 4.5-6.0 Hz, and its removal resulted in a lower DF for uni-orig compared with uni-res (5.1 ± 1.5 vs. 4.8 ± 1.5 Hz; p < .001). Compared with Bi, uni-res had a significantly greater area under the receiver operator curve (0.80 vs. 0.77; p < .05), specificity (86% vs. 76%; p < .001), and positive predictive value (43% vs. 30%; p < .001) for detecting low-voltage during AF. Similar improvements in specificity and positive predictive value were evident for uni-res versus uni-orig. Far-field EGM can be reliably removed from uni-orig using our novel, least-squares algorithm. Compared with Bi and uni-orig, uni-res is more accurate in detecting low-voltage regions during AF. This approach may improve substrate mapping and ablation during AF, and merits further study.

Safety and feasibility of same-day discharge in patients receiving pulmonary vein isolation-systematic review and a meta-analysis.

The purpose of this systematic review and meta-analysis was to evaluate the feasibility and safety of a same-day discharge protocol following pulmonary vein isolation (PVI). PubMed and Embase were systematically investigated from the inception to 20 July 2020. Studies on safety and feasibility of PVI for atrial fibrillation (AF) were included. Study-specific estimates were combined using one-group meta-analysis with a random-effects model. Seven observational studies investigating the safety and feasibility of same-day discharge protocols were identified. Of a total of 3656 patients who have undergone PVI for AF, the overall complication rate was 0.80% (95% confidence interval [CI], 0.20-1.40%). The readmission within 30-day following same-day discharge protocol occurred at a pooled rate of 3.6% (95% CI, 0.0-8.4%). Frequent complications following the procedure were complications related to vascular access (0.38%; 95% CI, 0.18-0.58%), and phrenic nerve injury (0.19%; 95% CI, 0.05-0.33%). The reported complications in SDD group were mainly based on results among patients without perioperative complications. The introduction of same-day discharge strategies might be safe and feasible in selected patients given the reported complication and re-admission rates in the current practice. Further prospective studies are needed to confirm these findings.

Ablation catheter orientation: In vitro effects on lesion size and in vivo analysis during PVI for atrial fibrillation.

Catheter-delivered radiofrequency (RF) lesion formation is a complex phenomenon, and few studies have explored the effect of catheter orientation on lesion size and catheter orientation behavior during pulmonary vein isolation (PVI) procedures. We evaluated the influence of catheter orientation on lesion dimensions in an in vitro experimental setting and investigated the catheter orientation behavior during PVI. 72 lesions were created in vitro on a porcine heart using a contact force catheter in a parallel, oblique, and perpendicular tip to tissue orientation. The superficial lesion length (SLL) increased shifting the catheter from perpendicular to parallel orientation. The intratissue absolute maximal lesion length (AML) was greater with an oblique catheter orientation. The lesion depth (LD) and the superficial lesion width (SLW) resulted similar with any orientation. Data from 21 PVI procedures in patients with paroxysmal atrial fibrillation using the "wide antral circumferential RF ablation" (WACA) technique were retrospectively analyzed. The mean contact angle among 1130 RF lesions was 28 ± 20°. A prevalent parallel orientation was noted in the anterior WACA segments, whereas it resulted more perpendicular in the posterior segments. Significant differences in catheter orientation between the three operators were found only in few WACA segments. In an in vitro setting, catheter orientation affects SLL and AML, but not LD and SLW. During PVI procedures, catheter orientation resulted mostly parallel to the endocardium. Catheter orientation varied among different WACA segments, but only small differences were found between three operators when considering similar WACA segments.

Cryoballoon pulmonary-vein isolation for atrial fibrillation with heart failure: results from a single-center cohort

Abstract Background Atrial fibrillation (AF) and heart failure (HF) are of growing prevalence and increasing mortality. Radiofrequency ablation is safe and effective for patients with AF and HF. Prognosis might be improved in patients treated. However, there is no prospective trial investigating efficacy and safety of cryoballon ablation in patients with AF and HF. Objective To prospectively compare cryoballoon ablation in patients with and without HF (defined as LVEF ≤40%) in terms of safety and efficacy. Methods Ongoing POLAR-HF trial is a prospective, investigator-initiated, single-center, non-inferiority, open-label study. We analyzed 244 consecutive patients who underwent cryoballoon ablation. Of these 217 had normal LVEF (age 68.1±9.6 years, CHA2DS2-VASc Score 2.5±1.3, 55.3% male) while 27 patients (11%) suffered from HF (age 70.4±8.6 years, CHA2DS2-VASc Score 3±1.2, 70.4% male). Follow-up was performed at 3, 6 and 12 months after ablation. Kaplan-Meier method was used to calculate 12-month event-rate estimates. Log-Rank Test to estimate hazard ratios in the primary analysis. Endpoints were: symptomatic AF relapse for efficacy and bleeding, stroke or death for safety. Results Analysis showed no difference in AF-free survival rate between patients with and without HF (81% vs. 76.3%, Log-Rank-Test P=0.81, Figure). Primary safety end point occurred in 5 patients with normal LVEF (2.3%) and none in the HF-group. No deaths were observed. Conclusion Results of POLAR-HF indicate that cryoballoon ablation is an effective ablation method for patients suffering from AF and HF. Event-Free Survival (Efficacy Endpoint) Funding Acknowledgement Type of funding source: None

Epicardial adipose tissue and atrial fibrillation: Possible mechanisms, potential therapies, and future directions.

Obesity plays an important role in the pathogenesis of atrial fibrillation (AF). Recently, rather than general fat distribution, epicardial adipose tissue (EAT) gains a growing concern. EAT is the local adipose deposition between myocardium and pericardium. Accumulated evidence revealed several distinguishing characteristics of EAT. It lies contiguously with the myocardium and could infiltration into myocardium, actively secrets cytokines and adipokines mediating inflammation or remodeling, and contains abundant ganglionated plexi. Clinical research also found EAT may be an independent risk factor of AF. Volume or thickness of EAT measured on CT or MRI could be applied as a predictor of presence, severity, and recurrence of AF. Some drugs, like antidiabetic drugs and lipid-lowing drugs, show ability to reduce EAT. Additional surgical ablation of EAT was also proved that it could improve outcome of pulmonary vein isolation for AF. In present review, we summarize recent epidemic, biological, and clinical findings about EAT and its possible role in AF.

Impact of coronary artery disease and revascularization on recurrence of atrial fibrillation after catheter ablation: Importance of ischemia in managing atrial fibrillation.

There are few studies analyzing the association between the presence of coronary artery disease (CAD) and recurrence of atrial fibrillation (AF). This study evaluated the clinical impact of concomitant CAD and coronary revascularization on the recurrence of AF after catheter ablation. From April 2008 to December 2015, 700 consecutive patients were treated with pulmonary vein isolation for AF as the initial procedure. Of those, 681 patients who simultaneously underwent coronary angiography were investigated. Patients with at least one coronary stenosis (≥70%) were classified as having obstructive CAD. Of 681 patients, 90 patients had CAD and 42 patients underwent percutaneous coronary intervention (PCI) for lesions with perfusion abnormalities on single-photon emission tomography. The recurrence of AF was significantly more frequent in patients with CAD (56%) than in those without CAD (39%) (P = .0011). On multivariable analysis, the predictors of AF recurrence were persistent or long-standing persistent AF [hazard ratio (HR): 1.36; 95% confidence interval (CI): 1.04-1.77; P = .023], left atrial diameter (HR: 1.04; 95% CI: 1.02-1.06; P < .0001), and concomitant CAD (HR: 1.45; 95% CI: 1.05-1.97; P = .024). The recurrence of AF in patients with PCI (38%) was significantly lower than in those without PCI (72%) (P = .0006), and E/E' significantly improved in patients with PCI (71%) than in those without PCI (42%; P = .001). Performing PCI for concomitant CAD significantly reduced AF recurrence (HR: 0.39; 95% CI: 0.20-0.72; P = .002). Patients with CAD had a significantly higher rate of AF recurrence than those without CAD. Coronary revascularization may reduce the recurrence of AF with improvement of left ventricular diastolic function.

Association of left atrium voltage amplitude and distribution with the risk of atrial fibrillation recurrence and evolution after pulmonary vein isolation: An ultrahigh-density mapping study.

Ultrahigh-density-voltagemapping (uHDV M) is a new tool that can add new insights into the pathophysiology of atrial fibrillation (AF). The aim of this study was to evaluate the performance of uHDV M in predicting postablation AF recurrence (AFR). We included 98 consecutive patients undergoing pulmonary vein isolation for AF (40.8% persistent) using an uHDV M system and followed for 1 year. The left atrium (LA) mean voltage (Vm ) and the Vslope (slope of the voltage histogram calculated by linear interpolation, with the relative frequency on the vertical axis and the bipolar potential on the horizontal axis) were calculated from 12 567 ± 5486 points per map. Patients with AFR (N = 29) had lower Vm and higher Vslope as compared with patients without AFR (N = 69). Receiver operating characteristic curves identified Vm as the strongest predictor of AFR, with a higher incidence of AFR in patients with Vm 0.758 mV (57.6%) or lower than patients with Vm higher than 0.758 mV (15.4%; P < .0001). Among patients with Vm higher than 0.758 mV, patients with Vslope 0.637 or higher exhibited higher (P = .043) AFR incidence (31.3%) than patients with Vslope lower than 0.637 (10.2%). This classification showed incremental predictive value over relevant covariables. Vm values were lower and Vslope values were higher in patients that progressed from paroxysmal to persistent AF. Patients with Vslope 0.637 or higher had a 14.2% incidence of postablation atypical atrial flutter, whereas patients with Vslope lower than 0.637 did not present this outcome. The risk of AFR, atrial flutter, and progression from paroxysmal to persistent AF can be detected by quantitative analysis of LA uHDV M identifying diverse patterns of atrial substrate alterations.

Balloon angioplasty versus stenting for pulmonary vein stenosis after pulmonary vein isolation for atrial fibrillation: A meta-analysis

BackgroundThe incidence of pulmonary vein stenosis (PVS) as complication after pulmonary vein isolation (PVI) for atrial fibrillation (AF) has decreased in the last decade. However, as PVI for AF is becoming more prevalent, the incidence remains considerable in absolute terms. The purpose of this meta-analysis is to investigate the optimal approach for management of PVS after PVI for AF. Methods and resultsWe searched electronic scientific databases for studies comparing plain balloon angioplasty (BA) versus stenting for PVS after PVI for AF. Aggregate data were pooled to perform a meta-analysis. The primary and secondary outcomes were restenosis requiring repeated intervention and procedure-related complications, respectively.A total of 4 studies, treating 315 PVS in 188 patients (BA, n=171 versus stent, n=144 PVS) were considered. After a median follow-up of 32months, the overall incidence of restenosis was 46%. A percutaneous therapy with BA was associated with a higher risk for restenosis requiring repeat intervention compared to stent (risk ratio — RR, 95% confidence interval [95% CI]=2.18 [1.64–2.89], p<0.001). Procedure-related complications were comparable between BA and stent (RR [95% CI]=0.96 [0.19–4.96], p=0.96). The time to diagnosis of PVS after PVI for AF did not modify the treatment effect for the primary outcome with BA versus stent (p for interaction=0.16). ConclusionsIn patients presenting PVS after PVI for AF, a percutaneous therapy with BA is associated with higher risk for restenosis requiring repeat intervention as compared to stent. These percutaneous therapies display comparable safety.

Contributors Toward Pulmonary VeinRestenosis Following SuccessfulIntervention.

This study sought to identify clinical and procedural risk factors associated with pulmonary vein (PV) restenosis. Pulmonary vein stenosis (PVS) is a rare but morbid complication of PV isolation for atrial fibrillation (AF) ablation. Interventions such as PV balloon angioplasty (BA) or stenting achieve excellent acute success; however, subsequent restenosis is common. A total of 113 patients underwent invasive treatment for severe PVS between 2000 and 2014 and were followed prospectively. Baseline patient and lesion characteristics were abstracted from chart review and analyzed. Univariate and multivariate analyses were performed using patient and procedural characteristics to determine which factors were associated with an increased risk for subsequent PV restenosis. Over a median follow-up of 4.6 years there was PVS recurrence in 75 veins; 52 veins (57%) were treated with index BA and 23 veins were treated with stenting. After multivariate analysis, the only patient factor that was significantly associated with restenosis was a history of more than 1 AF ablation (hazard ratio [HR]: 1.91; 95% confidence interval [CI]: 1.07 to 3.41; p= 0.03). Multivariate analysis on a per-vein level demonstrated a significantly lower risk of restenosis in veinstreated with a stent (HR: 2.84; 95% CI: 1.75 to 4.61; p< 0.0001). In veins treated with BA alone, inflation of the balloon to higher atmospheres significantly reduced the risk of recurrence (HR: 0.87; 95% CI: 0.78 to 0.98; p= 0.02). Restenosis is common after a successful PV intervention and the risk of restenosis is highest in those with a history of multiple AF ablations and in those treated with BA. Proceduralists should take into account the number of AF ablations a patient has undergone and should strongly consider stent deployment when intervening on PVS toreduce risk of restenosis.