Catheter Ablation Research Articles

Editorial to “Improvement in respiratory function and exercise tolerance following video‐assisted thoracoscopic diaphragm plication for symptomatic iatrogenic persistent diaphragm paralysis after radiofrequency catheter ablation”—An essential respiratory physiology every electrophysiologist should know‐

Editorial to “Improvement in respiratory function and exercise tolerance following video‐assisted thoracoscopic diaphragm plication for symptomatic iatrogenic persistent diaphragm paralysis after radiofrequency catheter ablation”—An essential <scp>respiratory physiology</scp> every <scp>electrophysiologist</scp> should know‐

Comparing cryoballoon and contact-force guided radiofrequency ablation in pulmonary vein isolation for atrial fibrillation in patients with hypertrophic cardiomyopathy.

Pulmonary vein isolation (PVI) employing cryoballoon (CB) or contact force-guided radiofrequency (CF-RF) catheter ablation has been established as an effective strategy for managing atrial fibrillation (AF). However, its efficacy in hypertrophic cardiomyopathy (HCM) remains to be further explored. This retrospective study analyzed 60 consecutive AF patients with HCM (average age 67 ± 10 years; 41 men) who were consecutively admitted to our hospital from January 2014 to December 2022 and underwent initial PVI. The patients were treated with CB (26 patients) or CF-RF (34 patients). Successful PVI was achieved in both groups without significant complications. In the CF-RF group, additional ablations were performed on the cavotricuspid isthmus (14.7% of patients) and the anterior line (2.9%). The CB group benefited from reduced procedural times (93 ± 31 vs. 165 ± 60min, p < 0.05) and decreased saline irrigation requirements (77.5 ± 31.4 vs. 870 ± 281.9 mL, p < 0.0001). Using a contrast medium was exclusive to the CB group (33.8 ± 4.2 mL). In a 12-month follow-up, the atrial tachyarrhythmia recurrence-free rates in the CB and CF-RF groups were comparable (77% and 76%, respectively; p = 0.63 according to the log-rank test). Notably, pulmonary vein reconnection was prevalent in most (7 out of 8) patients requiring a secondary ablation procedure. PVI is feasible as a strategy for AF in patients with HCM employing either CB or CF-RF techniques. While the recurrence-free rates were comparable in both groups, differences were noted in procedure duration, saline usage, and the need for a contrast medium.

Editorial to “Associations of the Fibrosis‐4 index with left atrial low‐voltage areas and arrhythmia recurrence after catheter ablation: Cardio‐hepatic interaction in patients with atrial fibrillation”

Editorial to “Associations of the Fibrosis‐4 index with left atrial low‐voltage areas and arrhythmia recurrence after catheter ablation: Cardio‐hepatic interaction in patients with atrial fibrillation”

Pre- and Post-Procedural Cardiac Imaging (CT and MRI) in Electrophysiology: A Clinical Consensus Statement of the European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI) of the ESC.

Imaging using cardiac computed tomography (CT) or magnetic resonance imaging (MR) has become an important option for anatomic and substrate delineation in complex atrial and ventricular tachycardia (VT) ablation procedures. CT more common than MR has been used to detect procedure-associated complications like esophageal, cerebral and vascular injury. This clinical consensus statement summarizes the current knowledge of CT and MR to facilitate electrophysiological procedures, the current value of real-time integration of imaging-derived anatomy and substrate information during the procedure and the current role of CT and MR in diagnosing relevant procedure-related complications. Practical advice on potential advantages of one imaging modality over the other is discussed for patients with implanted cardiac rhythm devices as well as for planning, intraprocedural integration and post-interventional management in atrial fibrillation (AF) and VT ablation patients. Establishing a team of electrophysiologists and cardiac-imaging specialists working on specific details of imaging for complex ablation procedures is key. CMR can safely be performed in most patients with implanted active cardiac devices. Standard procedures for pre- and post-scanning management of the device and potential CMR-associated device-malfunctions need to be in place. In VT patients imaging - specifically MR - may help to determine scar location and mural distribution in ischemic and non-ischemic cardiomyopathy patients beyond evaluating the underlying structural heart disease. Future directions in imaging may include the ability to register multiple imaging modalities, novel high-resolution modalities but also refinements of imaging-guided ablation strategies are expected.

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

Clinical and pathophysiologic determinants of catheter ablation outcome in hypertrophic cardiomyopathy with atrial fibrillation

The left atrial appendage closure by surgery 2 trial: statistical analysis plan for a randomized multicenter trial exploring if the closure of the left atrial appendage during open-heart surgery reduces stroke irrespective of patients’ stroke risk and preoperative atrial fibrillation status

BackgroundSurgical left atrial appendage (LAA) closure concomitant to open-heart surgery prevents thromboembolism in high-risk patients. Nevertheless, high-level evidence does not exist for LAA closure performed in patients with any CHA2DS2-VASc score and preoperative atrial fibrillation or flutter (AF) status—the current trial attempts to provide such evidence.MethodsThe study is designed as a randomized, open-label, blinded outcome assessor, multicenter trial of adult patients undergoing first-time elective open-heart surgery. Patients with and without AF and any CHA2DS2-VASc score will be enrolled. The primary exclusion criteria are planned LAA closure, planned AF ablation, or ongoing endocarditis. Before randomization, a three-step stratification process will sort patients by site, surgery type, and preoperative or expected oral anticoagulation treatment. Patients will undergo balanced randomization (1:1) to LAA closure on top of the planned cardiac surgery or standard care. Block sizes vary from 8 to 16. Neurologists blinded to randomization will adjudicate the primary outcome of stroke, including transient ischemic attack (TIA). The secondary outcomes include a composite outcome of stroke, including TIA, and silent cerebral infarcts, an outcome of ischemic stroke, including TIA, and a composite outcome of stroke and all-cause mortality. LAA closure is expected to provide a 60% relative risk reduction. In total, 1500 patients will be randomized and followed for 2 years.DiscussionThe trial is expected to help form future guidelines within surgical LAA closure. This statistical analysis plan ensures transparency of analyses and limits potential reporting biases.Trial registrationClinicaltrials.gov, NCT03724318. Registered 26 October 2018, https://clinicaltrials.gov/study/NCT03724318.Protocol versionhttps://doi.org/10.1016/j.ahj.2023.06.003.

Intracardiac echocardiography guided anatomical ablation of the arcuate ridge for drug refractory inappropriate sinus tachycardia.

Inappropriate sinus tachycardia (IST) is a common condition with frequently not tolerated beta-blockers or ivabradine and a high rate of complication in ablation strategy; we describe an alternative anatomical approach of sinus node (SN) modulation. This retrospective study describes a case series of 6 patients from two centers diagnosed with symptomatic IST undergoing SN ablation. The mean age was 40.6 ± 13.9 years; five of the six patients were female, 100% of patients reported heart palpitations, and 66% reported dizziness, the average heart rate(HR) on a 24-h Holter was 93.2 ± 7.9 bpm. HR during the first stage of a stress test using a standard Bruce protocol was 150 ± 70 bpm, The average HR on 24-h Holter postablation was 75 ± 5.6 bpm, the sinus rate HR during stage 1 of a Bruce protocol exercise stress test was 120 ± 10 bpm. This is the first case series reporting the acute and long-term results of a novel anatomical approach for SN modulation to treat IST targeting the arcuate ridge(AR) under intracardiac echography(ICE) guidance. The novel anatomic ICE-guided catheter ablation approach aimed to identify the earliest activation at the AR with an extension of RF lesions towardits septal region seems effective and safe to modulate the SN in symptomatic patients with IST refractory to medical treatment.

Concise guidelines of the European Cardiac Arrhythmias Society (ECAS) on "catheter ablation of atrial fibrillation": A prepublication of the methods in preparation of the final guidelines document.

Concise guidelines of the European Cardiac Arrhythmias Society (ECAS) on "catheter ablation of atrial fibrillation": A prepublication of the methods in preparation of the final guidelines document.

Anatomical and Electrophysiological Characteristics of Dual-Loop Re-Entry in Atypical Atrial Flutter: Implications for Mapping and Catheter Ablation

Atypical atrial flutter (AFL) can be challenging to ablate, especially when involving dual-loop re-entry. We sought to assess the electroanatomical characteristics of single- and dual-loop AFLs in patients undergoing catheter ablation. Methods: We analyzed 25 non-cavotricuspid isthmus-dependent macro-re-entrant AFL in 19 consecutive patients. Three-dimensional high-density activation mapping was performed, and active re-entry loops were confirmed by entrainment mapping. Results: Of 25 AFLs (24 left, 1 right atrial), 13 (52%) exhibited dual-loop re-entry. The most common circuits included, in 6/13 (46% of dual loops), a perimitral re-entry with a second loop around the right/left pulmonary veins (PV) and, in 6/13 (46%), involved a right PV ostium with a second loop around either a functional conduction block or another PV. Ablation at the common isthmus of dual-loop AFLs and at the critical isthmus of single-loop AFLs terminated the arrhythmia more frequently than ablation at a secondary isthmus of dual-loop AFLs (5/6 (83%) and 8/11 (73%) versus 1/8 (13%), respectively, p = 0.013). Conclusion: More than half of AFLs exhibited a dual-loop re-entrant mechanism. Most critical isthmuses were found at the mitral isthmus, the left atrial roof or right PV ostia. Ablation targeting the common isthmus resulted in a higher termination rate.

Micro-Costing Analysis for the Treatment of Atrial Fibrillation: An Economic Evaluation of the First Italian Experience of Same-Day Discharge Protocol for Cryoballoon Atrial Fibrillation Ablation

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its prevalence is expected to increase further due to the aging population, increasing prevalence of risk factors, improving detection methods, and broadening of catheter ablation indications. Along with limited healthcare resources and bed availability, these reasons led to the development of a same-day discharge (SDD) protocol. The aim of this study was to evaluate the health and economic impact of a routine adoption of same-day discharge after cryoballoon AF ablation. Methods: Consecutive patients with symptomatic and drug-refractory AF scheduled for first-time AF ablation were screened, and if deemed suitable, the SDD protocol was proposed and, if accepted, enrolled in the protocol. Results: A total of 324 patients were screened, and 118 were considered eligible for the SDD pathway. Fifty-two patients accepted the SDD pathway and were included in this study. The analysis showed that the variation in resource consumption associated with cryoablation in SDD is equal to EUR 739.85/patient. The analysis showed that the main cost driver for ordinary hospitalization was represented by the hospital stay, which was calculated to be 36% of the total cost. In total, there was a cost reduction of EUR 38.472 thanks to optimized AF patient management from the standard recovery setting to SDD. Conclusions: SDD after cryoballoon ablation of AF is feasible in selected patients with a standardized protocol.

Clinical implication of hyperuricemia on the recurrence of atrial fibrillation after catheter ablation

Clinical implication of hyperuricemia on the recurrence of atrial fibrillation after catheter ablation

Comparison between catheter ablation versus permanent pacemaker implantation as an initial treatment for tachycardia–bradycardia syndrome patients: a prospective, randomized trial

BackgroundClinical outcomes after catheter ablation (CA) or pacemaker (PM) implantation for the tachycardia–bradycardia syndrome (TBS) has not been evaluated adequately. We tried to compare the efficacy and safety outcomes of CA and PM implantation as an initial treatment option for TBS in paroxysmal atrial fibrillation (AF) patients.MethodsSixty-eight patients with paroxysmal AF and TBS (mean 63.7 years, 63.2% male) were randomized, and received CA (n = 35) or PM (n = 33) as initial treatments. The primary outcomes were unexpected emergency room visits or hospitalizations attributed to cardiovascular causes.ResultsIn the intention-to-treatment analysis, the rates of primary outcomes were not significantly different between the two groups at the 2-year follow-up (19.8% vs. 25.9%; hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.25–2.20, P = 0.584), irrespective of whether the results were adjusted for age (HR 1.12, 95% CI 0.34–3.64, P = 0.852). The 2-year rate of recurrent AF was significantly lower in the CA group compared to the PM group (33.9% vs. 56.8%, P = 0.038). Four patients (11.4%) in the CA group finally received PMs after CA owing to recurrent syncope episodes. The rate of major or minor procedure related complications was not significantly different between the two groups.ConclusionCA had a similar efficacy and safety profile with that of PM and a higher sinus rhythm maintenance rate. CA could be considered as a preferable initial treatment option over PM implantation in patients with paroxysmal AF and TBS.Trial registrationKCT0000155.

Successful catheter ablation of atrial tachycardia initiated with orthodromic capture of superior vena cava potentials.

Acase of successful catheter ablation of paroxysmal atrial fibrillation and atrial tachycardia is reported. After pulmonary vein isolation, atrial tachycardia was induced by the use of isoproterenol and burst pacing from the catheter in the right atrium. An attempt was made to create athree-dimensional (3D) map of the atrial tachycardia, but the atrial tachycardia was terminated in the middle of the mapping. The 3D map was insufficient but indicated that the superior vena cava was involved in the circuit. When the intracardiac electrograms were reviewed, it was found that the atrial tachycardia was initiated with orthodromic capture of superior vena cava potentials and it was considered that the atrial tachycardia involved the superior vena cava-right atrium junction. Accordingly, superior vena cava isolation was performed. After that, atrial fibrillation and atrial tachycardias were not induced by the use of isoproterenol and burst pacing. In this case, an intracardiac electrogram at the time of induction of the tachycardia was helpful for understanding the circuit of the tachycardia.

Safety and efficacy of anticoagulation therapy post atrial fibrillation ablation

Abstract Funding Acknowledgements None. Background Thromboembolic complications can be life-threatening during atrial fibrillation (AF) catheter ablation. The aim of our single center, retrospective study was to evaluate the safety and efficacy of continuous treatment using direct oral anticoagulants (DOACs) as an alternative to uninterrupted acenocoumarol for periprocedural anticoagulation. Purpose To record the safety and efficacy of the oral anticoagulants post atrial fibrillation ablation. Methods We studied 1999 patients undergoing AF catheter ablation between June 2013 and December 2021 in our center. All patients were assigned to take acenocoumarol (group 1, 194 patients) or DOACs (group 2, 1805 patients) for ≥2 months before the procedure. We compared thromboembolic and bleeding complications between the 2 groups. Results Our analysis showed no significant difference in major and minor complications between the 2 patient groups with the exception of the occurrence of groin hematoma with a clear superiority of DOACs (2.06%-0.5%, p&amp;lt;0.05). Specifically, 4 of 194 patients (2.06%) using uninterrupted acenocoumarol had a major complication (3 patients [1.55%] had transient ischemic attack resolved 8 hours later and 1 [0.52%] had pericardial tamponade, and 7 patients (3.61%) had minor complications (4 [2.06%] groin hematoma and 3 [1.55%] mild pericardial efussion). In group 2, 14 of 1805 patients (0.78%) had a major complication (11 patients had transient ischemic attack (0.61%) and 3 patients (0.17%) had pericardial tamponade). In the same group, 31 patients (1.72%) had a minor complication (3 patients [0.17%] presented with pseudoaneurysm or femoral arteriovenous fistula between the femoral artery and femoral vein, 19 [1.05%] with pericardial effusion &amp;lt;1 cm, and 9 [0.5%] groin hematoma). Conclusions DOACs and acenocoumarol have similar safety and effectiveness regarding thromboembolic complications prevention without increasing bleeding complications with the exception of the occurrence of groin hematoma with a clear superiority of DOACs.

3-Year Outcomes for Degenerative Mitral Regurgitation Repair in a Medicare Population.

Mitral valve repair (MVr) has become the standard therapy for degenerative mitral regurgitation (DMR), but real-world late mortality, reintervention, and readmission data are lacking. This study estimates MVr outcomes for DMR to 3 years in the Medicare fee-for-service population. There were 4,219 DMR patients older than 65 years undergoing MVr within the Medicare 100% standard analytic file from October 2015 to December 2018 who were evaluated. Outcomes were analyzed for isolated MVr patients (n = 2,433) and patients undergoing MVr with certain concomitant procedures: MVr + tricuspid valve surgery (TVS; n = 619), MVr + cardiac ablation (CA; n = 540), and MVr + left atrial appendage closure (n = 627). Outcomes over a 3-year period included all-cause mortality, reintervention, rehospitalization, and common complications. All outcomes were modeled with adjustments for patient demographics and comorbid conditions. The average age for all patients was 71.9 ± 5.2 years. Adjusted all-cause mortality and MV reintervention (surgery or transcatheter) at 3 years for the primary cohort of isolated MVr was 3.5% and 1.6%, respectively. Directionally higher mortality at 3 years was observed in patients with concomitant TVS or CA. All-cause readmission and cardiac readmission for isolated MVr was 37.0% and 14.1%, with the highest rates for those with concomitant TVS or CA. Acute kidney injury and stroke/transient ischemic attack were the most common adverse events over 3 years for all patients. The 3-year mortality and reintervention rates in Medicare patients undergoing degenerative MVr are low. Those undergoing concomitant TVS or CA had directionally higher mortality and cardiac readmission rates. These results help refine outcome benchmarks as new transcatheter MVr procedures continue to emerge.

Rescue retrograde coronary venous ethanol ablation of ventricular tachycardia storm in a patient with Lamin A/C cardiomyopathy: a case report

Abstract Background Left ventricular summit arrhythmias account for up to 14% of left ventricular (LV) arrhythmias. Ablation of LV summit arrhythmias is challenging and radiofrequency (RF) catheter ablation failure is frequent. Retrograde coronary venous ethanol infusion has been proposed as an alternative approach for the ablation of left ventricular summit arrhythmias. Case Summary A 47-year old man with Lamin A/C cardiomyopathy was referred for ablation of pleiomorphic ventricular tachycardia (VT) storm, with dominant morphology compatible with LV summit origin. He first received a combined endo- and epicardial RF ablation with elimination of 3 clinically relevant VT. However, the dominant VT could not be ablated due to proximity of the coronary vasculature and phrenic nerve and remained inducible. Accordingly, an urgent rescue redo procedure consisting of retrograde coronary venous ethanol ablation was performed. Based on best pacematch and precocity, the first septal, retro-pulmonary and first diagonal branch were infused with ethanol with immediate cessation of the tachycardia and non-inducibility. Anti-arrhythmic drugs were withdrawn while guideline directed medical therapy for heart failure was continued. No complications occurred. After 3 months, the patient remained free from any arrythmias. Discussion Ablation of LV summit arrythmias is challenging, especially in the context of electrical storm or in patients with structural heart disease. In such a situation, rescue ablation with retrograde coronary venous ethanol infusion represents an attractive alternative ablation modality.

Transesophageal echocardiography before atrial fibrillation ablation: To do or not to do?

Transesophageal echocardiography before atrial fibrillation ablation: To do or not to do?

Detection of Epicardial Connection Through Intercaval Bundle Involving Right Pulmonary Veins After Ipsilateral Circumferential Ablation by Intra-Atrial Activation Sequence Pacing From the Right Pulmonary Vein.

An epicardial connection (EC) through the intercaval bundle (EC-ICB) between the right pulmonary vein (RPV) and right atrium (RA) is one of the reasons for the need for carina ablation for PV isolation and may reduce the acute and chronic success of PV isolation. We evaluated the intra-atrial activation sequence during RPV pacing after failure of ipsilateral RPV isolation and sought to identify specific conduction patterns in the presence of EC-ICB. This study included 223 consecutive patients who underwent initial catheter ablation of atrial fibrillation. If the RPV was not isolated using circumferential ablation or reconnected during the waiting period, an exit map was created during mid-RPV carina pacing. If the earliest site on the exit map was the RA, the patient was classified into the EC-ICB group. The exit map, intra-atrial activation sequence, and RPV-high RA time were evaluated. First-pass isolation of the RPV was not achieved in 36 patients (16.1%), and 22 patients (9.9%) showed reconnection. Twelve and 28 patients were classified into the EC-ICB and non-EC-ICB groups, respectively, after excluding those with multiple ablation lesion sets or incomplete mapping. The intra-atrial activation sequence showed different patterns between the 2 groups. The RPV-high RA time was significantly shorter in the EC-ICB than in the non-EC-ICB group (69.2±15.2 versus 148.6±51.2 ms; P<0.001), and RPV-high RA time<89.0 ms was highly predictive of the existence of an EC-ICB (sensitivity, 91.7%; specificity, 89.3%). An EC-ICB can be effectively detected by intra-atrial sequencing during RPV pacing, and an RPV-high RA time of <89.0 ms was highly predictive.

The Novel Automated Peak Frequency Annotation Algorithm for Identifying High Frequency Electrogram Activity Following Pulmonary Vein Isolation in Atrial Fibrillation Ablation.

The Novel Automated Peak Frequency Annotation Algorithm for Identifying High Frequency Electrogram Activity Following Pulmonary Vein Isolation in Atrial Fibrillation Ablation.

Inhibition of Hmbox1 Promotes Cardiomyocyte Survival and Glucose Metabolism Through Gck Activation in Ischemia/Reperfusion Injury.

Exercise-induced physiological cardiac growth regulators may protect the heart from ischemia/reperfusion (I/R) injury. Homeobox-containing 1 (Hmbox1), a homeobox family member, has been identified as a putative transcriptional repressor and is downregulated in the exercised heart. However, its roles in exercise-induced physiological cardiac growth and its potential protective effects against cardiac I/R injury remain largely unexplored. We studied the function of Hmbox1 in exercise-induced physiological cardiac growth in mice after 4 weeks of swimming exercise. Hmbox1 expression was then evaluated in human heart samples from deceased patients with myocardial infarction and in the animal cardiac I/R injury model. Its role in cardiac I/R injury was examined in mice with adeno-associated virus 9 (AAV9) vector-mediated Hmbox1 knockdown and in those with cardiac myocyte-specific Hmbox1 ablation. We performed RNA sequencing, promoter prediction, and binding assays and identified glucokinase (Gck) as a downstream effector of Hmbox1. The effects of Hmbox1 together with Gck were examined in cardiomyocytes to evaluate their cell size, proliferation, apoptosis, mitochondrial respiration, and glycolysis. The function of upstream regulator of Hmbox1, ETS1, was investigated through ETS1 overexpression in cardiac I/R mice in vivo. We demonstrated that Hmbox1 downregulation was required for exercise-induced physiological cardiac growth. Inhibition of Hmbox1 increased cardiomyocyte size in isolated neonatal rat cardiomyocytes and human embryonic stem cell-derived cardiomyocytes but did not affect cardiomyocyte proliferation. Under pathological conditions, Hmbox1 was upregulated in both human and animal postinfarct cardiac tissues. Furthermore, both cardiac myocyte-specific Hmbox1 knockout and AAV9-mediated Hmbox1 knockdown protected against cardiac I/R injury and heart failure. Therapeutic effects were observed when sh-Hmbox1 AAV9 was administered after I/R injury. Inhibition of Hmbox1 activated the Akt/mTOR/P70S6K pathway and transcriptionally upregulated Gck, leading to reduced apoptosis and improved mitochondrial respiration and glycolysis in cardiomyocytes. ETS1 functioned as an upstream negative regulator of Hmbox1 transcription, and its overexpression was protective against cardiac I/R injury. Our studies unravel a new role for the transcriptional repressor Hmbox1 in exercise-induced physiological cardiac growth. They also highlight the therapeutic potential of targeting Hmbox1 to improve myocardial survival and glucose metabolism after I/R injury.