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Catheter ablation for atrial fibrillation (AF) is frequently used for the purpose of rhythm control and improved quality of life (QoL). Although success rates are high, a significant proportion of patients require redo ablation. Data are scarce on patient-centered outcomes and QoL in patients undergoing redo AF ablation. We aimed to assess QoL and clinical outcomes using a large prospectively maintained patient-reported outcomes (PRO) registry.All patients undergoing redo AF ablation (2013-2016) at our center were enrolled in a prospective registry for outcomes and assessed for QoL using automated PRO surveys (baseline, 3 and 6 months after ablation, every 6 months thereafter). Data were collected over 3 years of follow-up. The atrial fibrillation symptom severity scale (AFSSS) was used as the main measure for QoL. Additional variables included patient-reported improvement, AF burden, and AF-related healthcare utilization including emergency room (ER) visits and hospitalizations.A total of 848 patients were included (28% females, mean age 63.8, 51% persistent AF). By automated PRO, significant improvement in QoL was noted (baseline median AFSSS of 12 [5-18] and ranged between 2 and 4 on subsequent assessments; p .0001), with ≥70%of patients reported remarkable improvement in their AF-related symptoms. The proportion of patients in AF at the time of baseline survey was 36%, and this decreased to8% across all time points during follow-up (p .0001). AF burden was significantly reduced (including frequency and duration of episodes; p .0001), with an associated decrease in healthcare utilization after 6 months from the time of ablation (including ER visits and hospitalizations; p .0001). The proportion of patients on anticoagulants or antiarrhythmics decreased on follow-up across all time points (p .0001 for all variables).Most patients derive significant QoL benefit from redo AF ablation; with reduction of both AF burden and healthcare utilization.

BACKGROUND: Ablation is used for both rhythm control and improved quality of life (QoL) in atrial fibrillation (AF). It has been suggested that young adults may experience high recurrence rates after ablation and data remain lacking regarding QoL benefits. We aimed to investigate AF ablation outcomes and QoL benefits in young adults undergoing AF ablation using a large prospectively maintained registry and automated patient-reported outcomes (PRO). METHODS: All patients undergoing AF ablation (2013–2016) at our center were prospectively enrolled. Patients aged 50 years or younger were included. For PROs, QoL measures and symptoms were assessed at baseline, 3 months after ablation, and every 6 months thereafter. The AF severity score served as the main assessment of QoL. RESULTS: A total of 241 young adults (age, 16–50 years) were included (17% female, 40.3% persistent AF). In all, 77.2% of patients remained arrhythmia-free during the first year of follow-up (80% in nonstructural AF and 66% in structural AF). Using PROs, 90% of patients reported improvement in QoL throughout all survey time points up to 5 years postablation ( P P P CONCLUSIONS: Ablation remains an effective rhythm-control strategy in young adults with AF. Young adults also experience significant improvement in QoL with reduction of the frequency and duration of AF episodes and AF-related healthcare utilization.

Background: Confirming the presence and participation of concealed nodo-ventricular (cNV) or concealed His-ventricular (cHV) pathways in tachyarrhythmias is challenging. We describe novel observations to aid in diagnosing cNV or cHV pathways. Methods: We present 7 cases of cNV and cHV pathway-mediated arrhythmias and focus on several laboratory observations: (1) differential ventricular overdrive pacing (VOD) from the base versus apex, (2) response to His refractory premature ventricular complexes, (3) paradoxical atriohisian response (shorter atriohisian interval during tachycardia than that during sinus rhythm) in long RP tachycardia, and (4) the role of adenosine to aid in the diagnosis. Results: Three cases underwent differential VOD during tachycardia. All demonstrated a shorter postpacing interval minus tachycardia cycle length during basal pacing than apical pacing with one case exhibiting apical VOD results compatible with atrioventricular nodal reentrant tachycardia. Basal VOD was useful for localizing the ventricular connection in a case with cHV pathway. In 3 cases, His refractory premature ventricular complexes reset the tachycardia without conduction to the atrium, which excluded the involvement of an atrioventricular pathway or atrial tachycardia, or atrioventricular nodal reentrant tachycardia alone. One case had His refractory premature ventricular complexes followed by subsequent constant AA interval and then tachycardia termination, suggesting a bystander cNV pathway involvement. Two cNV pathway cases presented with long RP tachycardia had paradoxical atriohisian shortening of >15 ms, suggesting parallel activation of the atrium and the atrioventricular node. Adenosine terminated the tachycardia with retrograde block in 2 cases with cNV pathways but had no response on a cHV pathway. Conclusions: cNV and cHV pathways mediated tachyarrhythmias can present with variable clinical presentations. We emphasize the important role of differential VOD sites, His refractory premature ventricular complexes that reset or terminate the tachycardia without conduction to the atrium, paradoxical atriohisian response in long RP tachycardia, and the use of adenosine for diagnosing cNV and cHV pathways.

BackgroundObesity is a well-known risk factor for atrial fibrillation (AF).ObjectiveTo evaluate the effect of baseline obesity on procedural complications, AF recurrence, and symptoms following catheter ablation (CA).MethodsA total of 5841 patients undergoing AF ablation (2013-2021) were enrolled in a prospectively maintained registry. Primary endpoint was AF recurrence based on electrocardiographic documentation. Patients were categorized into 5 groups according to their baseline body mass index (BMI). Patients survey at baseline and at follow-up were used to calculate AF severity score (AFSS) as well as AF burden.ResultsMajor procedural complications were low (1.5%) among BMI sub-groups. At 3 years AF recurrence was highest in Class III obesity patients (48%) followed by Class II (43%), whereas Class I, normal, and overweight had similar results with lower recurrence (35%). In multivariable analyses, Class III obesity was independently associated with increased risk for AF recurrence (HR=1.30, P=0.01), whereas other groups had similar risk in comparison to normal weight. Baseline AFSS was lowest in normal weight, and highest in Obesity-III, median [interquartile range] 10 [5-16] vs 15 [10-21]. In all groups, CA resulted in improvement in their AFSS with a similar magnitude among the groups. At follow-up, AF burden was minimal and did not differ significantly between the groups.ConclusionAF ablation is safe with a low complication rate across all BMI groups. Morbid obesity (BMI ≥40) was significantly associated with reduced AF ablation success. However, ablation resulted in improvement in QOL including reduction of the AFSS, and AF burden.What is known?Obesity is an independent risk factor of atrial fibrillation (AF)Catheter ablation (CA) has emerged as a standard of care in arrhythmia management, leading to improvements in quality of life, reductions in hospitalizations, and potential reductions in major adverse clinical outcomes.More obese patients are being referred to catheter ablation of AF.What is new?AF ablation is safe with low complication rates across all BMI sub-groups (Morbid obesity (BMI ≥40) was associated with increased risk of AF recurrence after ablationUsing patient reported outcomes, AF Ablation resulted in improvement of quality of life regardless of BMI

Objectives This study sought to describe the electrophysiologic characteristics, diagnostic maneuvers, and treatment of a series of arrhythmias using concealed nodoventricular (cNV) or His-ventricular (cHV) pathways. Background Confirming the presence and participation of cNV or cHV pathways in tachyarrhythmias is challenging. Methods We present 4 cases of tachycardias with a participatory cNV or cHV pathway. Results The first patient had a narrow complex tachycardia with ventriculoatrial dissociation. Findings of an entrainment pacing from the right ventricle and fused premature ventricular complexes suggested cNV pathway involvement. The second patient had nonsustained narrow complex tachycardia with more ventricular than atrial complexes. The tachycardia exhibited an anterograde His-right bundle (RB) activation sequence and normal His-ventricular (HV) interval and consistently terminated with fused ventricular extra stimuli, suggesting cNV pathway participation. The third patient had a wide complex tachycardia (WCT) with either a right or left bundle branch block pattern. The WCT showed an eccentric His-RB activation sequence and short HV interval and terminated with fused premature ventricular complexes, suggesting a cHV (or concealed fasciculoventricular) pathway involvement. The fourth patient had a WCT with alternating bundle branch block morphologies with a short HV interval. Entrainment from the basal right ventricle demonstrated fusion and a short postpacing interval, suggesting cHV (or fasciculoventricular) pathway involvement. Ablation at the proximal RB rendered the tachycardia noninducible. Conclusions A structured approach can help diagnose and treat cNV or cHV pathways. We emphasize the importance of evaluating both the His-RB activation pattern and HV interval during sinus rhythm and tachycardia as well as the ventricular pacing study.

The Rhythmia™ system (Boston Scientific, Natick, MA, USA) facilitates the rapid acquisition of high-resolution electroanatomical and activation maps. However, there are limited data on its efficacy and safety in pediatric and adult congenital heart disease (CHD) patients. In a retrospective, observational cohort study, adult CHD and pediatric patients followed by pediatric cardiology underwent electrophysiologic study using the Rhythmia™ electroanatomic mapping system. Variables examined included the number of electroanatomical maps required, acquisition time, procedure time, fluoroscopy time, radiation dosage, and rate of recurrent arrhythmia. Twelve consecutive patients, including six male patients (50%), were included with an average age of 27.7 years (range: 11-64 years). Seven (58%) of these patients had a diagnosis of CHD [moderate complexity in two (17%) and great complexity in five patients (42%)] and 10 (83%) patients underwent ablation. A total of 37 high-density maps were created in 12 procedures, with a median of 8,140 mapping points, taking a median of 631 seconds. The median procedure time was 189.5 minutes. The median fluoroscopy time was 0.9 minutes, with eight (67%) patients receiving no fluoroscopy at all. Recurrence occurred in one patient (8%) over a median follow-up duration of 16 months (interquartile range: 12.8-17.3 months). No adverse periprocedural events were recorded. This study suggests the use of high-density electroanatomic mapping in adult CHD patients showed potential for rapid acquisition of highly detailed maps with minimal fluoroscopy time or risk of periprocedural events in the studied population.

Background Direct-to-consumer devices allow patients to record electrocardiograms (ECG) and detect atrial fibrillation (AF). Clinical adoption of these devices has been limited owing to the lack of efficient workflow. Objective To assess a new care model for following patients after AF ablation that uses a smartphone ECG coupled with a novel cloud-based platform. Methods This was a pilot study to describe AF detection, healthcare utilization, use of additional ECGs and cardiac monitors, and changes in anxiety after AF ablation. Patients presenting 3–4 months after early successful AF ablation were randomized into a control group with standard clinical follow-up or a self-monitoring group using smartphone ECG (Kardia Mobile, KM) coupled with a cloud-based platform (KardiaPro, KP) that alerted the physician when AF was detected and followed for 6 months Results A total of 100 patients were randomized: 51 to the KM/KP group and 48 to the control group (1 withdrew). AF was detected in 18 patients (18.2%), 11 (21.6%) in the KM/KP group and 7 (14.6%) in the control group (P = .42). AF detection occurred at a median of 68 and 91 days in the KM/KP and control groups, respectively (P = .93). These differences were not statistically significant. Healthcare utilization and changes in anxiety were similar between the groups. More patients required additional ECGs or cardiac monitors in the control group (27.1%) compared to the KM/KP group (5.9%) (P = .004). Conclusions Smartphone ECG with a cloud-based platform can be incorporated into the care of post–AF ablation patients without increasing anxiety and with less need for additional traditional monitors.

Objectives This study sought to characterize the presentations, electrophysiological features and diagnostic maneuvers for a series of unique arrhythmias involving the HPS. Background By v...

Background Virtual visits (VVs) are a modality for delivering health care services remotely through videoconferencing tools. Data about patient and physician experience in using VVs are limited. Objective The purpose of this study was to assess patient and physician experience with the use of VVs in cardiac electrophysiology. Methods We performed a prospective survey of cardiac electrophysiology patients and physicians who participated in an outpatient VV from December 2018 to July 2019. Results One-hundred consecutive VVs were included. Sixty-four patients elected to complete a survey. Patients rated their experience as either excellent/very good in scheduling a VV (87%), seeing their physician of choice (100%), transmitting arrhythmia data (88%), rating their physician's ability to communicate (98%), asking all questions (98%), rating the level of care received (98%), paying for the cost of a VV (67%), and rating their overall level of satisfaction (98%). Thirty-eight of 64 patients (59.4%) preferred a VV for their next visit, 12 of 64 (18.8%) preferred an in-office visit, 13 of 64 (20.3%) responded that their decision for a virtual or office visit depended on indication, and 1 of 64 (1.6%) had no preference. A total of 14 cardiac electrophysiologists participated in 100 VVs. Nine visits were not included due to technical difficulty. Physician responses to survey questions were rated as excellent/very good in the ability to communicate (92%), accessing monitoring data (95%), and overall level of satisfaction (98%). Conclusion In our small study population, most patients and physicians prefer VVs. Convenience, cost, and reason for follow-up were important determinants that affected both patient and physician preference.

Background Injury to the cardiac venous structures can complicate left ventricular lead placement for cardiac resynchronization therapy (CRT). Little is known about the outcomes of coronary sinus (CS) dissection with or without perforation. Objective The purpose of this study was to determine the outcomes in patients who had a CS injury during CRT implantation. Methods All patients undergoing procedures for CRT implantation at the Cleveland Clinic (2001–2018) were enrolled in a prospectively maintained registry for procedural profiles and complications. All patients with cardiac venous injuries during the procedures were included. Results CS injury occurred in 35 of 5011 patients (0.7%; 6 perforations (17.1%), 29 dissections without perforation (82.9%)). In patients with dissection in the absence of perforation, attempts at CS lead placement after dissection were successful in 21 of 29 patients (72.4%). In those with perforation (n=6, 17.1%), CS lead placement was successful in one of them (16.7%). Cardiac tamponade occurred in 2 patients (5.7%), and the procedure was aborted in both of them. Overall, CS lead placement failed in 13 patients (37%) but 9 (25.7%) underwent subsequent CRT with CS lead placement (n=6, 17.1%; median 58 days later) or epicardial leads (n=3, 8.6%). Three of the remaining 4 patients (8.6%) refused to undergo further procedures, and the fourth (2.9%) died of a complicated course. Conclusion CS injury is not common during CRT implantation procedures and did not preclude successful lead placement in 23 of 35 patients (65.7%) during the index procedure and 6 of 6 (100%) during the subsequent attempted procedures. A low rate of mortality was observed in such patients, but CS injury was associated with increased morbidity.

Introduction Atrioventricular nodal re-entry tachycardia (AVNRT) is the most common, regular narrow-complex tachycardia. The established treatment is catheter ablation of the AV nodal slow pathway (SP). However, in a select group of patients with long PR intervals in sinus rhythm, SP ablation can lead to AV block due to the absence of robust anterograde conduction through the fast pathway (FP). This report aims to demonstrate that AV nodal FP ablation is a reasonable approach in patients with AVNRT and poor or absent anterograde FP conduction. Methods and results Standard electrophysiology study techniques were used in the electrophysiology laboratory. Catheter ablations were performed using radiofrequency energy. Mapping of intracardiac activation was performed with electroanatomical mapping systems. Outcomes were assessed acutely during the procedure and during routine clinical follow-up. Six patients with first-degree AV block and recurrent AVNRT who underwent ablation of their tachycardia at our institution are presented. One patient underwent ablation of AV nodal SP resulting in high-degree AV block necessitating pacemaker implantation. The remaining five patients underwent ablation of the AV nodal FP guided by electroanatomical mapping of the earliest atrial activation in tachycardia. These five had successful treatment of the tachycardia with preservation of anterograde AV nodal conduction. Mapping and ablation approach to eliminate retrograde FP conduction are described. Conclusion In select patients with AVNRT and poor anterograde FP conduction, retrograde FP ablation is reasonable and is less likely to result in AV block and pacemaker dependency.

Background Narrow QRS tachycardia or premature beat with bystander atrial activation or ventricular-atrial dissociation is an unusual arrhythmia that can present diagnostic and therapeutic challenges. When ventricular-atrial conduction is robust, these arrhythmias can be difficult to distinguish from atrioventricular nodal reentry. Objective The purpose of this study was to describe the electrophysiology characteristics, diagnostic maneuvers, and treatment of these types of arrhythmias in a series of 7 cases. Methods Standard multipolar recording and pacing electrodes were used during electrophysiology studies. Catheter ablation was performed using radiofrequency or cryoenergy. Results During electrophysiology studies, ventricular-nodal or ventricular-Hisian conducting pathways were demonstrated to be responsible for the arrhythmias in all 7 cases. Successful ablation of these pathways using radiofrequency energy was accomplished in 6 of the 7 cases. Conclusion Ventricular-Hisian and ventricular-nodal associated tachyarrhythmias should be distinguished from typical forms of atrioventricular nodal reentrant tachycardia. Catheter ablation of these pathways can be successfully accomplished using mapping techniques described in our report.

Objectives This study sought to assess the incidence and outcomes of life-threatening complications from atrial fibrillation ablations in a high volume center. Background With increasing rates of atrial fibrillation ablation procedures, an increase in life-threatening procedure-related complications has been reported despite improvements in technology and ablation strategies. Methods Between 2000 and 2015, 10,378 patients underwent atrial fibrillation ablation at our institution and were enrolled in a prospectively maintained data registry. We identified all patients who had life-threatening cardiac, neurological, respiratory, or vascular complications to the ablation resulting in death or requiring emergent intervention. Results Major life-threatening complications occurred in 100 patients (0.9%). The most common was pericardial effusion requiring pericardiocentesis (0.5%), with 7 (0.07%) requiring emergent surgical repair for cardiac perforation. Stroke occurred in 27 patients (0.3%) with a vast majority having an ischemic stroke (93%) followed by hemorrhagic (3.5%) and ischemic stroke with hemorrhagic conversion (3.5%). The yearly incidence of stroke decreased from an average of 1.1% per year in the first tertile (2000 to 2004) to 0.2% per year in the last 2 tertiles (2005 to 2015). Permanent neurological deficits occurred in 23 patients. Vascular complications causing hemorrhagic shock occurred in 7 patients (0.06%), 5 of whom required urgent surgical intervention. Acute coronary syndrome requiring urgent percutaneous coronary revascularization occurred in 2 patients whereas 1 developed a right coronary artery air embolus. No procedural death or atrio-esophageal fistulae occurred. Conclusions In a large quaternary care center, the incidence of life-threatening complications is low. Experienced operators, high volume, continuous quality improvement initiatives, and efficient back-up support have allowed exemplary safety profiles and 0 procedure-related deaths over 16 years.

Background Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (Coherent™, Biosense Webster "Investigational"). Objective We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. Methods This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data was analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. Results A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 milliseconds). Of those, 67 cases with confirmed mechanism of the arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs 44.8%, P=0.009). In 5 patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (P for trend: 0.05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa 0.62 vs 0.47). Conclusions In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination. This article is protected by copyright. All rights reserved.

Objective To investigate left atrial shape differences on CT scans of atrial fibrillation (AF) patients with (AF+) versus without (AF−) post-ablation recurrence and whether these shape differences predict AF recurrence. Methods This retrospective study included 68 AF patients who had pre-catheter ablation cardiac CT scans with contrast. AF recurrence was defined at 1 year, excluding a 3-month post-ablation blanking period. After creating atlases of atrial models from segmented AF+ and AF− CT images, an atlas-based implicit shape differentiation method was used to identify surface of interest (SOI). After registering the SOI to each patient model, statistics of the deformation on the SOI were used to create shape descriptors. The performance in predicting AF recurrence using shape features at and outside the SOI and eight clinical factors (age, sex, left atrial volume, left ventricular ejection fraction, body mass index, sinus rhythm, and AF type [persistent vs paroxysmal], catheter-ablation type [Cryoablation vs Irrigated RF]) were compared using 100 runs of fivefold cross validation. Results Differences in atrial shape were found surrounding the pulmonary vein ostia and the base of the left atrial appendage. In the prediction of AF recurrence, the area under the receiver-operating characteristics curve (AUC) was 0.67 for shape features from the SOI, 0.58 for shape features outside the SOI, 0.71 for the clinical parameters, and 0.78 combining shape and clinical features. Conclusion Differences in left atrial shape were identified between AF recurrent and non-recurrent patients using pre-procedure CT scans. New radiomic features corresponding to the differences in shape were found to predict post-ablation AF recurrence.

This study sought to describe the electrophysiologic characteristics, diagnostic maneuvers, and treatment of a series of arrhythmias using concealed nodoventricular (cNV) or His-ventricular (cHV) pathways.Confirming the presence and participation of cNV or cHV pathways in tachyarrhythmias is challenging.We present 4 cases of tachycardias with a participatory cNV or cHV pathway.The first patient had a narrow complex tachycardia with ventriculoatrial dissociation. Findings of an entrainment pacing from the right ventricle and fused premature ventricular complexes suggested cNV pathway involvement. The second patient had nonsustained narrow complex tachycardia with more ventricular than atrial complexes. The tachycardia exhibited an anterograde His-right bundle (RB) activation sequence and normal His-ventricular (HV) interval and consistently terminated with fused ventricular extra stimuli, suggesting cNV pathway participation. The third patient had a wide complex tachycardia (WCT) with either a right or left bundle branch block pattern. The WCT showed an eccentric His-RB activation sequence and short HV interval and terminated with fused premature ventricular complexes, suggesting a cHV (or concealed fasciculoventricular) pathway involvement. The fourth patient had a WCT with alternating bundle branch block morphologies with a short HV interval. Entrainment from the basal right ventricle demonstrated fusion and a short postpacing interval, suggesting cHV (or fasciculoventricular) pathway involvement. Ablation at the proximal RB rendered the tachycardia noninducible.A structured approach can help diagnose and treat cNV or cHV pathways. We emphasize the importance of evaluating both the His-RB activation pattern and HV interval during sinus rhythm and tachycardia as well as the ventricular pacing study.

Background: We hypothesized that computerized morphological analysis of the left atrium (LA) and pulmonary veins (PVs) via fractal measurements of shape and texture features of the LA myocardial wall could predict atrial fibrillation (AF) recurrence after ablation. Methods: Preablation contrast computed tomography scans were collected for 203 patients who underwent AF ablation. The LA body, PVs, and myocardial wall were segmented using a semi-automated region growing method. Twenty-eight fractal-based shape and texture-based features were extracted from resulting segments. The top features most associated with postablation recurrence were identified using feature selection and subsequently evaluated with a Random Forest classifier. Feature selection and classifier construction were performed on a discovery cohort (D 1 ) of 137 patients; classifiers were subsequently validated on an independent set (D 2 ) of 66 patients. Dedicated classifiers to capture the fractal and morphological properties of LA body (C LA ), PVs (C PV ), and LA myocardial (C LAM ) tissue were constructed, as well as a model (C All ) capturing properties of all segmented compartments. Fractal-based models were also compared against a model employing machine estimation of LA volume. To assess the effect of clinical parameters, such as AF type and catheter technique, a clinical model (C clin ) was also compared against C All . Results: Statistically significant differences were observed for fractal features of C LA , C LAM , and C All in distinguishing AF recurrence ( P 1 . Using the 5 top features, C All had the best prediction performance (area under the receiver operating characteristic curve [AUROC], 0.81 [95% CI, 0.78–0.85]), followed by C PV (AUROC, 0.78 [95% CI, 0.74–0.80]), and C LA (AUROC, 0.70 [95% CI, 0.63–0.78]) on D 2 . The clinical parameter model C clin yielded an AUROC, 0.70 (95% CI, 0.65–0.77), while the atrial volume model yielded an AUROC, 0.59. Combining C All and C clin on D 2 improved the AUROC to 0.87 (95% CI, 0.82–0.93). Conclusions: Fractal measurements of the LA, PVs, and atrial myocardium on computed tomography scans were associated with likelihood of postablation AF recurrence.

Background: Many centers continue to routinely perform transesophageal echocardiograms before atrial fibrillation (AF) ablation procedures in patients treated with direct oral anticoagulants (DOACs). One study suggested that the procedures could be done without transesophageal echocardiogram but used intracardiac echocardiography imaging of the appendage from the right ventricular outflow. This study aimed to assess the safety of ablation for AF without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage in DOAC compliant patients. Methods: All patients undergoing AF ablation at the Cleveland Clinic (2011–2018) were enrolled in a prospectively maintained data registry. All consecutive patients presenting with AF or atrial flutter on DOAC were included. Periprocedural thromboembolic complications were assessed. Results: A total of 900 patients were included. Their median CHA 2 DS 2 -VASc score was 2 (interquartile range 1–3). All were on DOACs (333 rivaroxaban, 285 dabigatran, 281 apixaban, and 1 edoxaban). Thromboembolic complications occurred in 4 patients (0.3%): 2 ischemic strokes, 1 transient ischemic attack without residual deficit, and 1 splenic infarct; all with no further complications. Bleeding complications occurred in 5 patients (0.4%): 2 pericardial effusions (1 intraoperative, 1 after 30 days, both drained), 3 groin hematomas (1 of them due to needing heparin for venous thrombosis, none required interventions). No patients required emergent surgeries. Conclusions: In DOAC compliant patients who present for ablation in AF/atrial flutter, the procedures could be performed without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage; with low risk of complications.

Background: Dofetilide is one of the only anti-arrhythmic agents approved for atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF). However, postapproval data and safety outcomes are limited. In this study, we assessed the incidence and predictors of LVEF improvement, safety, and outcomes in patients with AF with LVEF ≤35% without prior implantable cardioverter defibrillator, cardiac resynchronization therapy, or AF ablation. Methods: An analysis of 168 consecutive patients from 2007 to 2016 was performed. Incidences of adverse events, drug continuation, implantable cardioverter defibrillator and cardiac resynchronization therapy implantation, LVEF improvement (>35%) and recovery (≥50%), AF recurrence, and AF ablation were determined. Multivariable regression analysis to identify predictors of LVEF improvement/recovery was performed. Results: The mean age was 64±12 years. Dofetilide was discontinued before hospital discharge in 46 (27%) because of QT prolongation (14%), torsades de pointe or polymorphic ventricular tachycardia/fibrillation (6% [sustained 3%, nonsustained 3%]), ineffectiveness (5%), or other causes (3%). At 1 year, 43% remained on dofetilide. Freedom from AF was 42% at 1 year, and 40% underwent future AF ablation. LVEF recovered (≥50%) in 45% and improved to >35% in 73%. Predictors of LVEF improvement included presence of AF during echocardiogram (odds ratio, 4.22 [95% CI, 1.71–10.4], P =0.002), coronary artery disease (odds ratio, 0.35 [95% CI, 0.16–0.79], P =0.01), left atrial diameter (odds ratio, 0.52 per 1 cm increase [95% CI, 0.30–0.90], P =0.01), and LVEF (odds ratio, per 1% increase, 1.09 [95% CI, 1.02–1.16], P =0.006). The C statistic was 0.78. Conclusions: In patients with LVEF ≤35%, who are potential implantable cardioverter defibrillator candidates, treated with dofetilide as an initial anti-arrhythmic strategy for AF, drug discontinuation rates were high, and many underwent future AF ablation. However, most patients had improvement in LVEF, obviating the need for primary prevention implantable cardioverter defibrillator.

Background: There is paucity of data regarding radiofrequency ablation for ventricular tachycardia (VT) in patients with cardiogenic shock and concomitant VT refractory to antiarrhythmic drugs on mechanical support. Methods: Patients undergoing VT ablation at our center were enrolled in a prospectively maintained registry and screened for the current study (2010–2017). Results: All 21 consecutive patients with cardiogenic shock and concomitant refractory ventricular arrhythmia undergoing bailout ablation due to inability to wean off mechanical support were included. Median age was 61 years, 86% were men, median left ventricular ejection fraction was 20%, 81% had ischemic cardiomyopathy, and PAINESD score was 18±5. The type of mechanical support in place before the procedure was intra-aortic balloon pump in 14 patients (67%), Impella CP in 2, extracorporeal membrane oxygenation in 2, extracorporeal membrane oxygenation and intra-aortic balloon pump in 2, and extracorporeal membrane oxygenation and Impella CP in 1. Endocardial voltage maps showed myocardial scar in 19 patients (90%). The clinical VTs were inducible in 13 patients (62%), whereas 6 patients had premature ventricular contraction–induced ventricular fibrillation/VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 with inducible clinical VTs. Substrate modification was performed in 15 patients with scar (79%). After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully, but 6 (29%) died during the index admission from persistent cardiogenic shock. Patients who had ventricular arrhythmia and cardiogenic shock on presentation had a trend toward lower in-hospital mortality compared with those who presented with cardiogenic shock and later developed ventricular arrhythmia. Conclusions: Bailout ablation for refractory ventricular arrhythmia in cardiogenic shock allowed successful weaning from mechanical support in a large proportion of patients. Mortality remains high, but the majority of patients were discharged home and survived beyond 1 year.

To investigate the learning curve for atrial fibrillation (AF), supraventricular tachycardia (SVT), and premature ventricular contraction (PVC) radiofrequency ablation (RFA) using zero fluoroscopy. This is a retrospective, single-center study of 167 patients undergoing ablation between 2016 and 2019. Minimal fluoroscopy approach was initiated after the first 20 cases of PVI and SVT RFA. Procedures were divided consecutively into increments of 10 cases to determine operator learning curve. A total of 64 (38%) had SVT ablations, 26 (16%) had PVC ablations, and 77 (46%) had AF and underwent PVI. For SVT RFA, fluoroscopy time improved from 4.1 ± 3.5 min during the first 10 cases to 0.8 ± 1.2 min after 50 cases (p = 0.0001). Sixty-two out of 64 (97%) of cases were successful. In PVC RFA, fluoroscopy time was 7.7 ± 5.5 min for the first 5, 2.3 ± 3.4 min after 15, and 0 min after 20 cases (p = 0.0008). Twenty-four out of 26 (92%) of cases were acutely successful with recurrence in 2/26 (8%) of patients over 9 ± 9 months. In PVI, fluoroscopy time was 9.9 ± 3.3 min over the first 20 cases, 2.6 ± 2.3 min after 40 cases, and 0.1 min after 50 cases (p

Background Programmed long AV delays and intrinsic long first degree AV block may increase risk for competitive atrial pacing (CAP) in devices without CAP avoidance algorithms. Methods Patients identified with CAP-induced mode switch episodes were followed clinically from September 2013 to August 2019. Attempts to avoid CAP included shortening of postventricular atrial refractory period (PVARP) or postventricular atrial blanking period (PVAB), or change to AAI or DDI modes. After observing associations with sensor-driven pacing, rate response was inactivated in a subset. Results Among 23 patients identified with CAP (22 St Jude Medical [Abbott]; one Boston Scientific Corporation devices), atrial fibrillation (AF) was induced in 12 (52%), lasting 10 seconds to 28 hours and 32 minutes. In one patient with an ICD CAP-induced AF with rapid ventricular rates that triggered a shock, inducing ventricular fibrillation, syncope, and another shock. Changing AV delays and shortening of PVARP failed to resolve CAP. After noting that all had CAP during sensor-driven pacing, rate response was inactivated in seven, resolving further device-induced AF in the three of seven that had prior CAP-induced AF. In two patients with intact AV conduction, AAI(R) pacing resolved further documentation of CAP. Conclusions CAP predominantly occurs during sensor-driven atrial pacing that competes with intrinsic atrial events falling in PVARP. Inactivation of the activity sensor or change to atrial-based pacing modes (AAI/R) appears to effectively prevent induction of device-induced atrial proarrhythmia. Ultimately, a corrective algorithm is needed to avoid CAP-induced proarrhythmia.

Purpose/objective(s) To study the heart motion using cardiac gated computed tomographies (CGCT) to provide guidance on treatment planning margins during cardiac stereotactic body radiation therapy (SBRT). Materials/methods Ten patients were selected for this study, who received CGCT scans that were acquired with intravenous contrast under a voluntary breath‐hold using a dual source CT scanner. For each patient, CGCT images were reconstructed in multiple phases (10%–90%) of the cardiac cycle and the left ventricle (LV), right ventricle (RV), ascending aorta (AAo), ostia of the right coronary artery (O‐RCA), left coronary artery (O‐LCA), and left anterior descending artery (LAD) were contoured at each phase. For these contours, the centroid displacements from their corresponding average positions were measured at each phase in the superior–inferior (SI), medial–lateral (ML), and anterior–posterior (AP). The average volumes as well as the maximum to minimum ratios were analyzed for the LV and RV. Results For the six contoured substructures, more than 90% of the measured displacements were

Background: Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (CoherentTM, Biosense Webster "Investigational"). Objective: We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. Methods: This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data was analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. Results: A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 milliseconds). Of those, 67 cases with confirmed mechanism of the arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs 44.8%, P=0.009). In 5 patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (P for trend: 0.05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa 0.62 vs 0.47). Conclusions: In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination.

Background The diagnosis and management of cardiac sarcoidosis (CS) along with the recognition of high risk features remains a significant challenge. Failing to identify reliable disease prognosticators often results in fatal ventricular arrhythmia or heart failure. Aims This study sought to determine the association of regional fluorodeoxyglucose positron emission tomography (18FDG PET) patterns and the presence of ventricular tachycardia (VT) storm and conduction disease in patients with CS. Methods In an observational cohort analysis, patients with a working diagnosis of CS who underwent 18FDG PET imaging were included. Baseline clinical data and 18FDG PET data were collected and analysed. Results A total of 57 patients with CS were studied. All had abnormal 18FDG PET imaging consisting of inflammation, scar or combination of both. VT storm was present in 33 per cent of the cohort, while 63 per cent had high grade conduction disease. Mean inflammatory burden noted on 18FDG PET in those with VT storm was 12 per cent. Inflammation involving ≥2 basal septal or mid septal segments (> 15 per cent myocardium) was an independent predictor of VT storm (OR: 9.62, 95 per cent CI 1.97–46.9, p=0.005). The degree of inflammatory burden and regional inflammation pattern on 18FDG PET demonstrated significant concordance with the presentation of VT storm. Inflammation in the anteroseptal segment was associated with high grade conduction disease (OR: 8.00, 95 per cent CI 0.94–68, p=0.029). Conclusion The presence of > 15 per cent myocardial inflammation on 18FDG PET imaging and regional inflammation ≥2 basal or mid septal segment significantly correlated with risk of ventricular arrhythmia specifically VT storm regardless of scar burden.

The aims of this study were to assess outcomes of pulmonary vein isolation (PVI) performed on athletes at a tertiary care center and to characterize its efficacy and physiological effects.The incidence of atrial fibrillation (AF) is increased in highly trained athletes and poses unique management challenges.Athletes were identified through a database of patients undergoing PVI from January 2000 through October 2015. Outcomes of AF ablation were defined in accordance with published guidelines. Available electrocardiographic, echocardiographic, and exercise treadmill testing data were also analyzed.The study population included 144 athletes (93% men; mean age 50.4 ± 8.6 years; 97 paroxysmal, 38 persistent, and 9 long-standing persistent) with median follow-up of 3 years. Single-procedure freedom from arrhythmia was 75%, 68%, and 33% at 1 year for paroxysmal, persistent, and long-standing persistent AF, respectively. Multiple-procedure freedom from arrhythmia off antiarrhythmic drugs was 86%, 76%, and 56% in respective groups at the end of follow-up (mean 1.4 ± 0.7 ablations per athlete). Compared with a matched cohort of nonathletes who underwent PVI, there was no difference in arrhythmia recurrence (log-rank p = 0.23). Excluding long-standing persistent AF, longer diagnosis-to-ablation time was the only variable in Cox proportional hazards analyses associated with arrhythmia recurrence (adjusted heart rate per log increase: 1.92; 95% confidence interval: 1.40 to 2.73; p 0.0001), and PVI within 2 years of diagnosis was notably associated with successful outcomes (log-rank p = 0.002). Sinus rate increased following the index ablation (mean 54 beats/min vs. 64 beats/min at1 year; p 0.0001), but maximum metabolic equivalents on exercise treadmill testing were unchanged (13.1 ± 1.2 vs. 12.7 ± 1.4; p = 0.44).PVI is an effective therapy in athletes with paroxysmal and persistent AF, and arrhythmia recurrence was no different from that among matched nonathletes. Early ablation was associated with improved success rates. Sustained cardioautonomic effects were observed following ablation, but exercise capacity was preserved.

This study sought to characterize the presentations, electrophysiological features and diagnostic maneuvers for a series of unique arrhythmias involving the HPS.By virtue of its unique anatomy and ion channel composition, the His-Purkinje system (HPS) is prone to a variety of arrhythmic perturbations.The authors present a collaborative multicenter case series of 6 patients with HPS-related arrhythmias. All patients underwent electrophysiological studies using standard multipolar catheters.In 3 patients, both typical and reverse bundle branch re-entry were seen, with 1 patient demonstrating "figure of 8" re-entry likely involving the septal fascicle. One patient presented with systolic dysfunction associated with a high premature ventricular complex burden, with the mechanism being bundle-to-bundle re-entrant beats masquerading as dual response to a single sinus impulse. Two patients were diagnosed with interfascicular re-entry. Diagnosis was aided by careful assessment of HV interval in sinus rhythm and ventricular tachycardia, multipolar catheters to assess the activation sequence of the His-right bundle branch, and fascicles and entrainment of different components of the HPS. Cure of the arrhythmia was achieved by ablation of the right bundle branch block in 3 patients, the left septal fascicle in 2 patients, and the left posterior fascicle in 1 patient.Proper diagnosis of re-entrant arrhythmias involving the HPS may prove challenging. We emphasize a structured approach for diagnosis and effective therapy.

Background Limited medical options are available for rhythm control in patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM). There are no published reports of dofetilide use in this population. Methods A retrospective chart review was conducted on 1,404 patients loaded on dofetilide for AF suppression at the Cleveland Clinic from 2008 to 2012, 25 of whom were found to have HCM. Results The HCM cohort was 32% female, 76% with persistent AF, mean age of 59 ± 10 years, and mean ejection fraction of 54 ± 9 %. Of the 25 patients, 21 were discharged on dofetilide, three discontinued during loading due to QTc prolongation, and one due to inefficacy. There were no adverse events during loading. Of those discharged on dofetilide, 11/21 (52%) were still on it at a median follow-up of 396 (198, 699) days at the time of the chart review. For those in whom it was discontinued, the median time on the drug was 301 (111, 738) days. Of the 10 patients who discontinued dofetilide during follow-up, six were due to inefficacy, one postablation, one postheart transplant, one due to death secondary to lung cancer, and one due to worsening edema. Conclusions Dofetilide was well tolerated in this group of patients with AF and HCM and it facilitated management of AF in 21/25 (84%) patients. Further research is needed to assess the safety and efficacy of dofetilide in order to develop evidence-based guidelines for the pharmacological management of AF in this population.

INTRODUCTION Management of persistent atrial fibrillation (PersAF) remains challenging, and many patients are left on medical therapy after a failed first ablation. In patients with recurrent symptomatic arrhythmias after PersAF ablation, we aimed to compare outcomes of repeat ablation and medical therapy versus medical therapy alone. METHODS AND RESULTS All 682 consecutive patients with recurrent symptomatic arrhythmia after a first ablation for PersAF at our institution (2005-2012) were included. Repeat ablation with continuation of medical therapy was performed in 364 patients (Group 1) and 318 were only medically managed (Group 2). The outcome of interest was freedom from arrhythmia recurrence beyond a 3-month blanking period. Separate analyses were performed to assess this endpoint totally off antiarrhythmics (primary endpoint) or alternatively with/without use of antiarrhythmics (secondary endpoint). Over a median follow-up of 26 months, 41.5% of Group 1 patients met the primary endpoint and remained free from arrhythmia recurrence off antiarrhythmics (vs. 14.5% in Group 2, P