Radiofrequency (RF) ablation for the treatment of atrial fibrillation has gained widespread acceptance since the concept was introduced by Haissaguerre et al a quarter of a century ago. High power short duration ablation has been widely adopted in the management of atrial fibrillation. Evidence for combining lesion size index and high power short duration ablation is lacking. In this issue of the journal, Cai et al evaluated the combination of HPSD with LSI with a focus on long-term efficacy.

A document by David Slotwiner. Click on the document to view its contents.

Catheter ablation of atrial fibrillation (AF) in patients with heart failure associated with a reduced EF (HFrEF) was associated with a significantly lower rate of a composite endpoint of death from any cause or hospitalization for worsening heart failure (HF) than medical therapy in the CASTLE-AF trial. In patients with HF and also with a preserved EF (HFpEF), AF is known to be associated with increased mortality. Although the particular benefit in patients with an EF >35% may suggest the need for prospective randomized control trial data in patients with HF to assess the role of ablation as a first-line therapy as Sessions AJ, et al. stated, we believe at present that 1) whether there is structural heart disease detected by cardiac images and 2) whether the left atrial voltage is generally low, should be assessed “before ablation” in each patient with HF to achieve a successful ablation.

Introduction: Pulmonary vein isolation (PVI) using radiofrequency (RF) and cryoballoon (Cryo) ablation are standard approaches for rhythm control of symptomatic atrial fibrillation. Both strategies involve scar formation of the left atrium (LA). There have been few studies investigating the differences in residual fibrosis and scar formation in patients undergoing RF and Cryo using cardiac magnetic resonance imaging (CMR).     Methods: The current study is a sub-analysis of the control arm of the Delayed-Enhancement MRI Determinant of Successful Catheter Ablation of Atrial Fibrillation study (DECAAF II). The study was a multicenter, randomized, controlled, single blinded trial that evaluated atrial arrhythmia recurrence (AAR) between PVI alone and PVI plus CMR atrial fibrosis guided ablation. Pre-ablation CMR and 3–6-month post ablation CMR were obtained to assess baseline LA fibrosis and scar formation respectively.     Results: Of the 843 patients randomized in the DECAAF II trial, we analyzed the 408 patients in the primary analysis control arm that received standard PVI. Five patients received combined RF and Cryo ablations so were excluded from this sub-analysis. Of the 403 patients analyzed, 345 underwent RF and 58 Cryo. The average procedure duration was 146 minutes for RF and 103 minutes for Cryo (p = 0.001). The rate of AAR at ~15 months occurred in 151 (43.8%) patients in the RF group and 28 (48.3%) patients in the Cryo group (p = 0.62). On 3-month post CMR the RF arm had significantly more covered fibrosis (3.6% vs. 3.0%, p = 0.04) and scar (8.8% vs. 6.4%, p = 0.001) compared to Cryo. Patients with ≥ 6.5% LA scar on 3-month post CMR had less AAR independent of ablation technique (RF p = 0.009, Cryo p = 0.02). Cryo caused a greater percentage of right and left pulmonary vein (PV) scar (p = 0.04, p = 0.02) and less non-PV scar (p = 0.009) compared to RF. On Cox regression Cryo patients free of AAR had a greater percentage of left PV scar (p = 0.01) and less non-PV scar (p = 0.004) compared to RF free of AAR.     Conclusion: In this sub-analysis of the control arm of the DECAAF II trial, there was no significant difference in the rate of AAR in patients undergoing PVI alone between RF vs. Cryo. Post ablation LA scar ≥ 6.5% predicted freedom from AAR, independent of ablation technique. Cryo formed a greater percentage of PV scar and less non-PV scar compared to RF, which may have prognostic implications.

Editorial accompanying ‘Implantation of a leadless pacemaker in young adults’

December 12, 2022To the Editors of the Journal of Cardiovascular Electrophysiology:Please find the editorial for manuscript ID JCE-22-0730.R2 attached.Thank you,Steven Zweibel MDTitle: What We Don’t Know Might Harm Our Patients: AF Detection Utilizing a Single Chamber ICDShort Title: Atrial Arrhythmia Detection in Single Chamber ICD PatientsSteven L. Zweibel MD, FACC, FHRS

Catheter ablation for treatment of symptomatic non-paroxysmal atrial fibrillation remains challenging. Clinical failure and need for continued medical therapy or repeat ablation is common, especially in more advanced forms of atrial fibrillation. Hybrid ablation has emerged as a more effective and safe therapy than endocardial-only ablation particularly for longstanding persistent atrial fibrillation as demonstrated by the randomized controlled CONVERGE trial. Hybrid ablation requires collaboration of electrophysiologists and cardiac surgeons to develop specific workflows. This review describes the Hybrid Convergent approach in the context of available ablation options and offers guidance for workflow development and patient selection.

Introduction: Ventricular arrhythmia (VA) from the left ventricular summit (LVS) is a common origin of VA, which resulting LV dysfunction in some patients. However, the predictors of LV cardiomyopathy were not well-elucidated. The present study sought to investigate the risk factor of LV cardiomyopathy and the outcome in patients with LVS VA Methods: Between 2013 and 2018, a total of 139 patients (60.7% men; mean age 53.2 ± 13.9 years-old) underwent catheter ablation for LVS VA from two centers. Detailed patient demographics, electrocardiograms, electrophysiological characteristics, and clinical outcomes were extracted for analysis. LV cardiomyopathy was defined as LV ejection fraction (LVEF) <50%. Results: Acute procedural success was achieved in 92.8 % of patients. There were 40 patients (28.8%) with LV cardiomyopathy, and the mean LVEF improved from 37.5 ± 9.3% to 48.5 ± 10.2% after ablation ( p < 0.001). After multivariate analysis, the independent predictors of LV dysfunction were wider QRS duration of the VA (odds ratio [OR]1.02; 95% confidence interval [CI]: 1.00-1.04; p = 0.046) and the absolute earliest activation time discrepancy (AEAD) between epicardium and endocardium (OR 1.05; 95% confidence interval CI: 1.00-1.09; p = 0.048). After ablation, the LV function was completely recovered in 20 patients (50%). The predictors for irreclaimable LV function included wider PVC QRS duration (OR 1.09; 95% CI: 1.02-1.17; p = 0.012) and poorer LVEF (OR 0.85; 95% CI: 0.74-0.97; p = 0.020). Conclusion: In patients with VA from LVS, PVC QRS duration and AEAD predicted the deteriorating LV systolic function. Catheter ablation could reverse the LV remodeling. Narrower QRS duration and better LVEF predicted a better recovery of LV function after ablation.

Background: The Micra Coverage with Evidence Development (CED) Study is a novel comparative analysis of Micra (leadless VVI) and transvenous single-chamber ventricular pacemakers (transvenous VVI) using administrative claims data. Objective: To compare chronic complications, device reinterventions, heart failure hospitalizations, and all-cause mortality after 3 years of follow-up.  Methods: U.S. Medicare claims data linked to manufacturer device registration information were used to identify Medicare beneficiaries with a de novo implant of either a Micra VR leadless VVI or transvenous VVI pacemaker from March 9, 2017-December 31, 2018. Unadjusted and propensity score overlap-weight adjusted Fine-Gray competing risk models were used to compare outcomes at 3 years.   Results: Leadless VVI patients (N=6,219) had a 32% lower rate of chronic complications and a 41% lower rate of reintervention compared with transvenous VVI patients (N=10,212) (chronic complication hazard ratio [HR] 0.68; 95% CI, 0.59-0.78; reintervention HR 0.59; 95% CI 0.44-0.78). Infections rates were significantly lower among patients with a leadless VVI (<0.2% versus 0.7%, P<0.0001). Patients with a leadless VVI also had slightly lower rates of heart failure hospitalization (HR 0.90; 95% CI 0.84-0.97). There was no difference in the adjusted 3-year all-cause mortality rate (HR 0.97; 95% CI, 0.92-1.03).  Conclusion: This nationwide comparative evaluation of leadless VVI versus transvenous VVI de novo pacemaker implants demonstrated that the leadless group had significantly fewer complications, reinterventions, heart failure hospitalizations, and infections than the transvenous group at 3 years, confirming that the previously reported shorter-term advantages associated with leadless pacing persist and continue to accrue in the medium-to-long-term.

Laser- based PVI has been around for many years and this modality of ablation is to provide a continuous circular overlapping lesions around the PVs' ostia. In order to ensure the continuity of the lesion, a camera is embedded in the system as to guide the placement of sequential applications with the target to make an adequate overlapping of two contiguous lesions as to reduce the likelihood of gaps. The first version of the system required the operator to manually rotate the catheter as to create a continuous arc of lesion around the PV's ostium. This approach is time-consuming, with a substantial overall time for each PV. The evolvement of the technique has been recently offered, with a novel semi-automated VGLA as to improve ablation efficiency by using a motorized system which moves the laser arc continuously in order to reduce the application time and, hopefully, minimize the creation of gaps.

A document by George Crossley. Click on the document to view its contents.

Can We Trust the Force?Frank Pelosi, Jr., MD, FHRS, FACCAssociate Professor of MedicineDepartment of Internal MedicineCardiac Electrophysiology SectionUniversity of Michigan Medical SchoolAnn Arbor, MichiganCorresponding Author:Frank Pelosi, Jr, MD, FACC, FHRS1500 East Medical Center DriveAnn Arbor MI. [email protected] words: contact force, radiofrequency ablationWord count: 1165 excluding referencesInvited manuscript for JCE-22-0822.R2

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, p<0.001) and were more often female (48.7% vs 28.6%, p=0.04). CMR was performed in 32 patients with UVA (82.1%), whereas flecainide challenge, stress ECG, genetic testing and EPS were only performed in a minority of patients. Overall, the use of a second-line investigation suggested an aetiology in 17 patients with UVA (43.5%). Compared to patients with VA of clear aetiology, UVA patients had lower rates of antiarrhythmic drug prescription (64.1% vs 88.9%, p=0.003) and had a higher rate of device-delivered tachy-therapies (30.8% vs 14.3%, p=0.045). Conclusion: 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.

The exponential rise in the incidence of peri-mitral flutter has paralleled the increasing use of more extensive atrial substrate ablation for atrial fibrillation (AF). Given the relative paucity of randomised evidence to support its role in AF management, mitral isthmus ablation should largely be reserved for patients with peri-mitral flutter. Catheter ablation for peri-mitral flutter is challenging due to complex anatomic relationships. The aim of this report is to review the anatomic considerations and approaches to catheter ablation for peri-mitral flutter.

New therapeutic possibilities open up in the nonpharmacological rate control of patients with atrial fibrillation, and an approach with an ablation line around the AVN could be useful both for modulating the ventricular response and for safer AV ablation if this is finally required.

Introduction: Capsulectomy is recommended in patients with cardiac implantable electronic device (CIED) infection after transvenous lead extraction (TLE) but is time-consuming and requires extensive tissue debridement. In this study, we describe the outcomes of chlorhexidine gluconate (CHG) scrubbing in lieu of capsulectomy for the treatment of CIED infections. Methods: This retrospective observational study included patients who underwent TLE for CIED-related infections. In the capsulectomy group, complete capsulectomy was performed after hardware removal. In the CHG group, thorough scrubbing of the generator pocket with 20 cc of 2% CHG followed by irrigation with approximately 500 cc of sterile normal saline (SNS) was performed. The primary outcomes included reinfection and hematoma formation in the generator pocket. Secondary outcomes included any adverse reaction to chlorhexidine, the need for reintervention, infection-related mortality, and total procedural time. Results: A total of 102 patients (mean age 67.2±13 years, 32.4% female) underwent CIED extraction with either total capsulectomy (n=54) or CHG (n=48) scrubbing. Hematoma formation was significantly higher in the capsulectomy group vs. the CHG group (13% vs. 0%, p=0.014), with no significant differences in the reinfection rate. Capsulectomy was associated with longer procedural time (133.7±78.5vs. 89.9±51.8 minutes, p=0.002). No adverse reactions to CHG were found. Four patients (4.3%) died from worsening sepsis: 3 in the capsulectomy group and 1 in the CHG group (p=0.346). Conclusions: In patients with CIED infections, the use of CHG without capsulectomy resulted in a lower risk of hematoma formation and shorter procedural times without an increased risk of reinfection or adverse events associated with CHG use.

Should We Limit Antiarrhythmic Drug Choice in Patients

Is Esophageal Temperature Management Needed During Cryoballoon Ablation for Atrial Fibrillation?Bachir Lakkis MD, Marwan M. Refaat, MDDivision of Cardiology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, LebanonRunning Title: Is Esophageal Temperature Management Needed During CBA for AF?Words: (excluding the title page and references): 462Keywords: Catheter Ablation, Atrial Fibrillation, Heart Diseases, Cardiovascular Diseases, Cardiac ArrhythmiasFunding: NoneDisclosures: NoneCorresponding Author:Marwan M. Refaat, MD, FACC, FAHA, FHRS, FASE, FESC, FACP, FAAMATenured Professor of MedicineDirector, Cardiovascular Fellowship ProgramDepartment of Internal Medicine, Cardiovascular Medicine/Cardiac ElectrophysiologyDepartment of Biochemistry and Molecular GeneticsAmerican University of Beirut Faculty of Medicine and Medical CenterPO Box 11-0236, Riad El-Solh 1107 2020- Beirut, LebanonUS Address: 3 Dag Hammarskjold Plaza, 8th Floor, New York, NY 10017, USAOffice: +961-1-350000/+961-1-374374 Extension 5353 or Extension 5366 (Direct)Atrial fibrillation (AF) is one of the most frequently occurring arrhythmias globally. Risk factors such as aging, hypertension, cardiac and pulmonary diseases, alcohol consumption, smoking, obesity and obstructive sleep apnea play an important role in the development of AF.(1-2) AF is a leading cause of ischemic stroke worldwide and is associated with increased mortality. (3) AF management depends on four pillars: risk factor management, anticoagulation depending on the CHA₂DS₂-VASc score, rate control and rhythm control. (4) The application of thermal energy in ablation, such as in cryoablation, can cause rare complications such as an esophageal injury, esophageal perforation and atrial-esophageal fistula. (5,6). Numerous technologies have been developed to avoid this problem and include esophageal temperature surveillance, using reduced temperatures, real time visualization of the esophagus in addition to making use of an esophageal cooling device. (7-9)In the current issue of the Journal of Cardiovascular Electrophysiology, Sink et al. have conducted a single-center pilot study to assess the utilization of an esophageal warming device to avoid the development of esophageal thermal injury (ETI) while utilizing cryoballoon ablation (CBA). Alternative studies have shown that using a cooling device has been beneficial in reducing the risk of ETI formation for patients undergoing RFA. (10,11) Thus, the authors have enrolled 42 patients undergoing CBA with AF refractory to medical therapy and have randomized them into 2 groups. In the first group, 23 patients undergoing CBA used an esophageal warming device such as esophageal heat-exchange tube (WRM) while the other 19 patients undergoing CBA used traditional luminal esophageal temperature (LET) to monitor the esophageal temperatures. The authors have conducted upper endoscopy monitoring of the esophagus the next day and subsequently, classified ETI into 4 grades. They have observed in the WRM group a paradoxical increase in ETI in comparison to the other group which used LET. Moreover, the authors have perceived a direct link between ETI formation, total freeze time and colder temperature usage. However, this study has several limitations, including the small population size. Furthermore, the study results are based on a single device employment which is EnsoETM® device (Attune Medical, Chicago, IL). Therefore, the effects of using other warming devices are not known.Overall, the authors should be praised on their efforts for conducting the first pilot study to evaluate the effects of using an esophageal warming device for patients undergoing CBA and for providing cardinal insight into the safety of utilizing such a device. In addition, the results of this study have tremendous clinical implications. Certainly, patients undergoing CBA might benefit from using higher temperature (above -51 °) and lower freezing time (<300 seconds) to avert developing ETI. Further studies incorporating more patients should be conducted to elucidate whether using an esophageal warming device is associated with a beneficial or a detrimental effect.References1. Kornej J, Börschel CS, Benjamin EJ, Schnabel RB. Epidemiology of Atrial Fibrillation in the 21st Century. Circulation Research. 2020;127(1):4-20. doi: doi:10.1161/CIRCRESAHA.120.316340.2. Maan A, Mansour M, Anter E, Patel VV, Cheng A, Refaat MM, Ruskin JN, Heist EK. Obstructive Sleep Apnea and Atrial Fibrillation: Pathophysiology and Implications for Treatment. Crit Pathw Cardiol Jun 2015; 14 (2): 81-5.3. Migdady I, Russman A, Buletko AB. Atrial Fibrillation and Ischemic Stroke: A Clinical Review. Semin Neurol. 2021;41(04):348-64.4. Chung MK, Refaat M, Shen WK, Kutyifa V, Cha YM, Di Biase L, Baranchuk A, Lampert R, Natale A, Fisher J, Lakkireddy DR. Atrial Fibrillation: JACC Council Perspectives. J Am Coll Cardiol. Apr 2020; 75 (14): 1689-1713.5. Kapur S, Barbhaiya C, Deneke T, Michaud GF. Esophageal Injury and Atrioesophageal Fistula Caused by Ablation for Atrial Fibrillation. Circulation. 2017;136(13):1247-55. doi: doi:10.1161/CIRCULATIONAHA.117.025827.6. D’Avila A, Ptaszek LM, Yu PB, Walker JD, Wright C, Noseworthy PA, Myers A, Refaat M, Ruskin JN: Left Atrial-Esophageal Fistula After Pulmonary Vein Isolation. Circulation May 2007; 115(17): e432-3.7. Dagres N, Anastasiou-Nana M. Prevention of atrial-esophageal fistula after catheter ablation of atrial fibrillation. Curr Opin Cardiol. 2011 Jan;26(1):1-5. doi: 10.1097/HCO.0b013e328341387d. PMID: 21099683.8. Leung LW, Gallagher MM, Santangeli P, Tschabrunn C, Guerra JM, Campos B, Hayat J, Atem F, Mickelsen S, Kulstad E. Esophageal cooling for protection during left atrial ablation: a systematic review and meta-analysis. J Interv Card Electrophysiol. 2020 Nov;59(2):347-355. doi: 10.1007/s10840-019-00661-5. Epub 2019 Nov 22. PMID: 31758504; PMCID: PMC7591442.9. Arruda, M.S., Armaganijian, L., Base, L.D., Rashidi, R. and Natale, A. (2009), Feasibility and Safety of Using an Esophageal Protective System to Eliminate Esophageal Thermal Injury: Implications on Atrial-Esophageal Fistula Following AF Ablation. Journal of Cardiovascular Electrophysiology, 20: 1272-1278. https://doi.org/10.1111/j.1540-8167.2009.01536.x10. Leung LW, Gallagher MM, Santangeli P, Tschabrunn C, Guerra JM, Campos B, Hayat J, Atem F, Mickelsen S, Kulstad E. Esophageal cooling for protection during left atrial ablation: a systematic review and meta-analysis. J Interv Card Electrophysiol. 2020 Nov;59(2):347-355. doi: 10.1007/s10840-019-00661-5. Epub 2019 Nov 22. PMID: 31758504; PMCID: PMC7591442.11. Tschabrunn CM, Attalla S, Salas J, Frankel DS, Hyman MC, Simon E, Sharkoski T, Callans DJ, Supple GE, Nazarian S, Lin D, Schaller RD, Dixit S, Marchlinski FE, Santangeli P. Active esophageal cooling for the prevention of thermal injury during atrial fibrillation ablation: a randomized controlled pilot study. J Interv Card Electrophysiol. 2022 Jan;63(1):197-205. doi: 10.1007/s10840-021-00960-w. Epub 2021 Feb 23. PMID: 33620619.