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Pericardial bleeding is a rare but life-threatening complication of atrial fibrillation (AF) ablation. Patients taking uninterrupted oral anticoagulation (AC) may be at increased risk for refractory bleeding despite pericardiocentesis and administration of protamine. In such cases, andexanet alfa can be given to reverse rivaroxaban or apixaban. In this study, we aim to describe the rate of acute hemostasis and thromboembolic complications with andexanet for refractory pericardial bleeding during AF ablation.In this multicenter, case series, participating centers identified patients who received a dose of apixaban or rivaroxaban within 24 hours of AF ablation, developed refractory pericardial bleeding during the procedure despite pericardiocentesis and administration of protamine and received andexanet. Eleven patients met inclusion criteria, with mean age of 73.5 ± 5.3 years and median CHAIn patients on uninterrupted apixaban or rivaroxaban, who develop refractory pericardial bleeding during AF ablation, andexanet can achieve hemostasis thereby avoiding the need for emergent surgery. However, there is a risk of thromboembolism following administration. This article is protected by copyright. All rights reserved.

Although efficacious, catheter ablation (CA) of ventricular arrhythmias (VAs) originating from left ventricular (LV) papillary muscles (PAPs) has the potential to affect mitral valve (MV) function.The aim of this study was to determine whether lesions delivered during CA of VAs from LV PAPs affected MV function.Consecutive patients undergoing CA of LV PAP VAs from January 2015 to December 2020 in whom both preprocedural and postprocedural transthoracic echocardiography was performed were included. Radiofrequency ablation was performed with an irrigated-tip catheter with or without contact force sensing and intracardiac echocardiographic guidance. The PAPs were delineated into segments: tip, body, and base. Pre- and post-CA transthoracic echocardiograms were reviewed to assess MV regurgitation, which was graded 0 (none), 1 (mild), 2 (moderate), or 3 (severe). A change of ≥2 grades from baseline was considered significant.A total of 103 patients (mean age 63 ± 15 years, 78% men) were included. VAs were ablated from the anterolateral PAP in 35% (n = 36), posteromedial PAP in 55% (n = 57), and both PAPs in 10% (n = 10). Lesion distribution was as follows: PAP tip in 52 (50%), PAP base in 34 (33%), PAP body in 13 (13%), and entire PAP in 4 (4%). The mean number of lesions delivered was 16 ± 13 (median 14). Of 103 patients, 102 (99%) showed no change in MV function.Using intracardiac echocardiographic guidance, lesions can be safely delivered on various aspects of this structure without adverse impact on MV function.

The right ventricle (RV) is uncommonly implicated in postinfarction ventricular tachycardia (VT). The prevalence and features of the RV substrate participating in postinfarction VT are undefined.The purpose of this study was to characterize critical right ventricular substrate (CRVS) involvement in patients with postinfarction VT.We retrospectively reviewed 1279 patients with postinfarction VT undergoing catheter ablation at our center from January 2000 through May 2020. Cases with CRVS defined by conclusive demonstration of participation in VT with activation, entrainment, and/or pacemapping during sinus rhythm were identified.CRVS was identified in 27 of 1279 patients (2.1%): age 65 ± 13 years, 96% male, median left ventricular (LV) ejection fraction 25%, and 93% with left bundle branch block (LBBB) morphology VT. CRVS was identified by RV activation and/or entrainment mapping (n = 19) or by the presence of low-voltage abnormal electrograms with excellent pacemap for the targeted VT and noninducibility after ablation (n = 8). VT termination during RV ablation occurred in 15 patients. After median follow-up of 20 months (interquartile range 9-53 months) and median of 2 procedures (interquartile range 1-3), 22 of 27 patients (80%) had no VT recurrence and 11 (41%) died.The RV contains critical substrate elements of postinfarction VT in at least 2.1% of cases. RV mapping should be considered in cases in which LV mapping fails to demonstrate adequate targets, particularly in patients with LBBB morphology VT.

Ventricular tachycardia (VT) substrate in left ventricular (LV) nonischemic cardiomyopathy (NICM) consists of fibrosis with surviving myocardium.The purpose of this study was to determine whether, in patients with LV NICM and sustained VT, reduced QRS amplitude and QRSf during sinus rhythm can identify the presence and location of abnormal septal (S-NICM) and/or free-wall (FW-NICM) VT substrate.We compared patients with NICM and VT (group 1) with electroanatomic mapping septal (S-NICM; n = 21) or free-wall (FW-NICM; n = 20) VT substrate to a 38-patient reference cohort (group 2) with cardiac magnetic resonance imaging (cMRI) and NICM but no VT referred for primary prevention implantable cardioverter-defibrillator (26 [68.4%] with late gadolinium enhancement).Group 1 had lower QRS amplitude in leads II (0.60 ± 0.22 vs 0.86 ± 0.35, P.001), aVR (0.60 ± 0.24 vs 0.75 ± 0.31, P = .002), aVF (0.48 ± 0.20 vs 0.70 ± 0.28, P.001), and VIn LV NICM, low frontal plane QRS (0.55 mV in aVF) is associated with VT substrate. Although multilead QRS fractionation is associated with the presence and location of VT substrate, it is frequently identified in patients without VT with cMRI abnormalities.

Right ventricular (RV) pacing-induced cardiomyopathy (PICM) is typically defined as left ventricular systolic dysfunction resulting from electrical and mechanical dyssynchrony caused by RV pacing. RV PICM is common, occurring in 10-20% of individuals exposed to frequent RV pacing. Multiple risk factors for PICM have been identified, including male sex, wider native and paced QRS durations, and higher RV pacing percentage, but the ability to predict which individuals will develop PICM remains modest. Biventricular and conduction system pacing, which better preserve electrical and mechanical synchrony, typically prevent the development of PICM and reverse left ventricular systolic dysfunction after PICM has occurred.

Despite the global COVID-19 pandemic, during the past 2 years, there have been numerous advances in our understanding of arrhythmia mechanisms and diagnosis and in new therapies. We increased our understanding of risk factors and mechanisms of atrial arrhythmias, the prediction of atrial arrhythmias, response to treatment, and outcomes using machine learning and artificial intelligence. There have been new technologies and techniques for atrial fibrillation ablation, including pulsed field ablation. There have been new randomized trials in atrial fibrillation ablation, giving insight about rhythm control, and long-term outcomes. There have been advances in our understanding of treatment of inherited disorders such as catecholaminergic polymorphic ventricular tachycardia. We have gained new insights into the recurrence of ventricular arrhythmias in the setting of various conditions such as myocarditis and inherited cardiomyopathic disorders. Novel computational approaches may help predict occurrence of ventricular arrhythmias and localize arrhythmias to guide ablation. There are further advances in our understanding of noninvasive radiotherapy. We have increased our understanding of the role of His bundle pacing and left bundle branch area pacing to maintain synchronous ventricular activation. There have also been significant advances in the defibrillators, cardiac resynchronization therapy, remote monitoring, and infection prevention. There have been advances in our understanding of the pathways and mechanisms involved in atrial and ventricular arrhythmogenesis.

Background Interatrial septal tachycardias (IAS-ATs) following atrial fibrillation (AF) ablation or cardiac surgery are rare, and their management is challenging. Objective The purpose of this study was to investigate the electrophysiological features and outcomes associated with catheter ablation of IAS-AT. Methods We screened 338 patients undergoing catheter ablation of ATs following AF ablation or cardiac surgery. Diagnosis of IAS-AT was based on activation mapping and analysis of response to atrial overdrive pacing. Results Twenty-nine patients (9%) had IAS-AT (cycle length [CL] 311 ± 104 ms); 16 (55%) had prior AF ablation procedures (median 3; range 1–5), 3 (10%) had prior surgical maze, and 12 (41%) had prior cardiac surgery (including atrial septal defect surgical repair in 5 and left atrial myxoma resection in 1). IAS substrate abnormalities were documented in all patients. Activation mapping always demonstrated a diffuse early IAS breakout with centrifugal biatrial activation, and atrial overdrive pacing showed a good postpacing interval (equal or within 25 ms of the AT CL) only at 1 or 2 anatomically opposite IAS sites in all cases. Ablation was acutely successful in 27 patients (93%) (from only the right IAS in 2, only the left IAS in 9, both IAS sides with sequential ablation in 13, and both IAS sides with bipolar ablation in 3). After median follow-up of 15 (6–52) months, 17 patients (59%) remained free from recurrent arrhythmias. Conclusion IAS-ATs are rare and typically occur in patients with evidence of IAS substrate abnormalities and prior cardiac surgery. Catheter ablation can be challenging and may require sequential unipolar ablation or bipolar ablation.

Factor XI (FXI) deficiency is an autosomal inherited, milder bleeding disorder that may predispose to a potential risk of life-threatening bleeding during childbirth or surgery. Unfortunately, data regarding obstetric and perioperative management of this condition are scarce, with limited cases reviewed in the last decade. Therefore, the present study aimed to expand this database and identify factors associated with increased bleeding risk. We performed a retrospective chart review of patients with FXI deficiency who underwent childbirth or other surgical procedures between August 2011 and April 2021 within a single academic health system and identified 198 patients who underwent 252 procedures, including 143 vaginal deliveries, 63 cesarean deliveries, and 46 other surgical procedures. Thirty-three of the 252 procedures resulted in bleeding complications. On multivariable logistic regression analysis, personal history of bleeding was the strongest predictor of perioperative or obstetric bleeding (odds ratio [OR], 5.92; P = .001). Higher FXI levels were correlated with lower odds of bleeding (OR, 0.72 with every 10 U/dL increase in FXI level; P = .05). On receiver operative characteristic analysis, FXI level of >40 U/dL predicted a lower bleeding risk with reasonable specificity (75%) but lacked sensitivity (47%). A family history of bleeding, ethnicity, genotype, preprocedural partial thromboplastin time, and platelet levels were not associated with bleeding risk. There were no cases of epidural or spinal hematoma associated with neuraxial anesthesia. FXI levels remain stable during pregnancy and repeated measurements may not be necessary.

Background: Data on atrial fibrillation (AF) ablation and outcomes are limited in patients with congenital heart disease (CHD). We aimed to investigate the characteristics of patients with CHD presenting for AF ablation and their outcomes. Methods: A multicenter, retrospective analysis was performed of patients with CHD undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using 2014 Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society guidelines. Clinical data were collected. One-year complete procedural success was defined as freedom from atrial tachycardia or AF in the absence of antiarrhythmic drugs or including previously failed antiarrhythmic drugs (partial success). Results: Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±13.3 years. CHD complexity categories included 147 (61.3%) simple, 68 (28.3%) intermediate, and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had trialed at least one antiarrhythmic drug. Forty-six patients (22.1%) had reduced systemic ventricular ejection fraction Conclusions: AF ablation in CHD was safe and resulted in AF control in a majority of patients, regardless of complexity. Future work should address the most appropriate ablation targets in this challenging population.

Data regarding the age-specific outcomes of VT ablation in patients with structural heart disease (SHD) are scarce. We performed a systematic review and meta-analysis to evaluate the outcomes of VT ablation in elderly vs. younger patients with SHD. MEDLINE/PubMed, Cochrane, and Google Scholar and references comparing VT ablation in elderly vs. younger patients were screened and studies included if matching inclusion and exclusion criteria. Five retrospective studies enrolling 2778 SHD patients (868 elderly vs. 1910 younger) were included. Compared to younger subjects, the elderly showed similar results in terms of acute ablation success (OR 0.78, 95% CI 0.54–1.13, p = 0.189) and minor complications (OR 1.74, 95% CI 0.74–4.09, p = 0.205), a trend toward a higher risk of major complications (OR 2.30, 95% CI 0.83–6.40, p = 0.110) and significantly higher rates of all complications (OR 2.67, 95% CI 1.51–4.71, p = 0.001) and periprocedural mortality (OR 1.93, 95% CI 1.24–3.01, p = 0.004). At a mean follow-up of 18 months, elderly patients showed similar long-term VT recurrence rate (OR 1.02, 95% CI 0.85–1.22, p = 0.861) and higher all-cause mortality (OR 2.00, 95% CI 1.40–2.86, p

Objectives The goal of this study was to characterize the relationship between DF, the electroanatomic mapping (EAM) substrate, and outcomes of catheter ablation of VT in NICM. Background A substantial proportion of patients with nonischemic dilated cardiomyopathy (NICM) and ventricular tachycardia (VT) do not have scar detectable by cardiac magnetic resonance late gadolinium enhancement (LGE) imaging. In these patients, the significance of diffuse fibrosis (DF) detected with T1 mapping has not been previously investigated. Methods This study included 51 patients with NICM and VT undergoing catheter ablation (median age 55 years; 77% male subjects) who had no evidence of LGE on pre-procedural cardiac magnetic resonance. Post-contrast T1 relaxation time determined on the septum was assessed as a surrogate of DF burden. The extent of endocardial low-voltage areas (LVAs) at EAM was correlated with T1 mapping data. Results Bipolar LVAs were present in 22 (43%) patients (median extent 15 cm2 [8 to 29 cm2]) and unipolar LVA in all patients (median extent 48 cm2 [26 to 120 cm2]). A significant inverse correlation was found between T1 values and both unipolar-LVA (R2 = 0.64; β = –0.85; p Conclusions In patients with NICM and no evidence of LGE undergoing catheter ablation of VT, DF estimated by using post-contrast T1 mapping correlates with the voltage abnormality at EAM and seems to affect post-ablation outcomes.

Adverse structural and electrical remodeling underlie persistent atrial fibrillation (PersAF). Restoration of sinus rhythm (SR) prior to ablation in PersAF may improve the underlying substrate, thus improving arrhythmia outcomes. The aim of this study was to evaluate if the presence of SR at time of ablation is associated with improved long-term arrhythmia outcomes of a limited catheter ablation (CA) strategy in PersAF.Patients with PersAF undergoing pulmonary vein isolation at our institution from 2014-2018 were included. We compared patients who presented for ablation in SR (by cardioversion and/or antiarrhythmic drugs [AADs]) to those who presented in AF. Primary outcome of interest was freedom from atrial arrhythmias (AAs) on or off AADs at 1 year after single ablation. Secondary outcomes included freedom from AAs on or off AADs overall, freedom from AAs off AADs at 1 year, and time to recurrent AF.Five hundred seventeen patients were included (322 presented in AF, 195 SR). The primary outcome was higher in those who presented for CA in SR as compared to AF (85.6% vs. 77.0%, p = 0.017). Freedom from AAs off AAD at 12 months was also higher in those presenting in SR (59.0% vs. 44.4%; p = 0.001) and time to recurrent AF was longer (p = 0.008). Presence of SR at CA was independently associated with the primary outcome at 12 months (OR 1.77; 95% CI 1.08-2.90) and overall (OR 1.89; 95% CI 1.26-2.82).Presence of SR at time of ablation is associated with improved long-term arrhythmia outcomes of limited CA in PersAF.

The type 1 electrocardiographic (ECG) pattern diagnostic of Brugada syndrome (BrS) can be dynamic. Limited studies have rigorously evaluated the temporal stability of the Brugada ECG pattern.We sought to evaluate fluctuations of the Brugada pattern in serial resting ECGs from BrS patients managed within a large health care system.In our cohort of BrS patients with at least 2 standard, resting ECGs recorded on separate clinical encounters, we evaluated serial changes in the Brugada pattern and categorized patients into 1 of 3 groups: dynamic was defined as the presence of both type 1 and non-type 1 patterns in available ECGs; the provoked-only group was defined as having a non-type 1 Brugada pattern across resting ECGs; and the persistent group was defined as having a type 1 pattern on all ECGs. We also evaluated the clinical risk in this cohort according to the Shanghai risk score.In 72 patients with BrS (mean age 46 ± 15 years, 69% male), 828 standard, resting ECGs were recorded over a median duration of 30.2 (interquartile range 6.3-68.1) months. The dynamic group comprised 50 (69% of the cohort) patients, the provoked-only group consisted of 17 patients (24% of the cohort), and the persistent group included 5 patients. No significant differences were detected in the total number of ECGs evaluated during the follow-up period between any of the groups. Only sinus node dysfunction and a prior cardiac arrest were associated with the persistent type 1 group. The majority of patients had a low annualized risk of lethal arrhythmic events.Most BrS patients have a dynamic Brugada pattern noted on longitudinal, resting ECGs. Expert consensus statements should provide clarity on the frequency of obtaining resting ECGs in patients suspected of having BrS during follow-up.

Background: Left ventricular (LV) scar on late gadolinium enhancement (LGE) cardiac magnetic resonance has been correlated with life-threatening arrhythmic events in patients with apparently idiopathic ventricular arrhythmias (VAs). We investigated the prognostic significance of a specific LV-LGE phenotype characterized by a ringlike pattern of fibrosis. Methods: A total of 686 patients with apparently idiopathic nonsustained VA underwent contrast-enhanced cardiac magnetic resonance. A ringlike pattern of LV scar was defined as LV subepicardial/midmyocardial LGE involving at least 3 contiguous segments in the same short-axis slice. The end point of the study was time to the composite outcome of all-cause death, resuscitated cardiac arrest because of ventricular fibrillation or hemodynamically unstable ventricular tachycardia and appropriate implantable cardioverter defibrillator therapy. Results: A total of 28 patients (4%) had a ringlike pattern of scar (group A), 78 (11%) had a non-ringlike pattern (group B), and 580 (85%) had normal cardiac magnetic resonance with no LGE (group C). Group A patients were younger compared with groups B and C (median age, 40 vs 52 vs 45 years; P, SCOPUS: ar.j, info:eu-repo/semantics/published

Severe endoscopically detected esophageal thermal lesions (EDELs) have been associated with higher risk of progression to atrio-esophageal fistula (AEF) following radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). We sought to evaluate safety and feasibility of active esophageal cooling using the Attune Medical Esophageal Heat Transfer Device (EnsoETM) to limit frequency or severity of EDELs. We sought To evaluate safety and feasibility of active esophageal cooling using the Attune Medical Esophageal Heat Transfer Device (EnsoETM) to limit frequency or severity of EDELs Consecutive patients undergoing first-time RFCA were randomized in a 1:1 fashion to esophageal cooling (device group) or standard temperature monitoring (control group). Ablation on the posterior wall was performed with a maximum power of 30W for up to 20s. All patients underwent EGD within 48 h. Endoscopy findings were classified as 1, erythema–mild injury; 2, superficial ulceration–moderate injury; 3, deep ulceration–significant injury; and 4, fistula/perforation. Severe EDELs were defined as grade 3 or 4 lesions. Forty-four patients completed the study (22 device group, 22 control group). Adjunctive posterior wall isolation was performed more frequently in the device group (11/22, 50% vs. 4/22, 18%). EDELs were detected in 5/22 (23%) control group patients, with mild or moderate injury in 2/5 patients (40%) and severe thermal injury in 3/5 patients (60%). In the device group, EDELs were detected in 8/22 (36%) patients, with mild or moderate injury in 7/8 (87%) patients and severe thermal injury in 1/8 (12%) patients. There was no acute perforation or AEF during follow-up. Active esophageal cooling may reduce the occurrence of severe EDELs. A larger randomized study is warranted to further evaluate the benefit of this strategy.

ObjectiveTo evaluate the prognosis of patients with ischemic stroke according to the timing of an atrial fibrillation (AF) diagnosis, we created an inception cohort of incident stroke events and compared the risk of death between patients with stroke with (1) sinus rhythm, (2) known AF (KAF), and (3) AF diagnosed after stroke (AFDAS).MethodsWe used the Penn AF Free study to create an inception cohort of patients with incident stroke. Mortality events were identified after linkage with the National Death Index through June 30, 2017. We also evaluated initiation of anticoagulants and antiplatelets across the study duration. Cox proportional hazards models evaluated associations between stroke subtypes and death.ResultsWe identified 1,489 individuals who developed an incident ischemic stroke event: 985 did not develop AF at any point during the study period, 215 had KAF before stroke, 160 had AF detected ≤6 months after stroke, and 129 had AF detected >6 months after stroke. After a median follow-up of 4.9 years (interquartile range 1.9–6.8), 686 deaths occurred. The annualized mortality rate was 8.8% in the stroke, no AF group; 12.2% in the KAF group; 15.8% in the AFDAS ≤6 months group; and 12.7% in the AFDAS >6 months group. Patients in the AFDAS ≤6 months group had the highest independent risk of all-cause mortality even after multivariable adjustment for demographics, clinical risk factors, and the use of antithrombotic therapies (hazard ratio 1.62 [1.22–2.14]). Compared to the stroke, no AF group, those with KAF had a higher mortality risk that was rendered nonsignificant after adjustment.ConclusionsThe AFDAS group had the highest risk of death, which was not explained by comorbidities or use of antithrombotic therapies.

INTRODUCTION Cryoballoon ablation (CBA) is an alternative to radiofrequency ablation (RFA) for ablation of atrial fibrillation (AF) and real-world comparisons of this strategy are lacking. As such, we sought to compare patient and periprocedural characteristics and outcomes of CBA versus RFA in the Get With the Guidelines AFIB Registry. METHODS Categorical variables were compared via the χ2 test and continuous variables were compared via the Wilcoxon rank-sum test. Adjusted analyses were performed using overlap weighting of propensity scores. RESULTS A total of 5247 (1465 CBA, 3782 RFA) ablation procedures were reported from 33 sites. Those undergoing CBA more often had paroxysmal AF (60.0% vs. 48.8%) and no prior AF ablation (87.5% vs. 73.8%). CHA2 DS2 -VASc scores were similar. Among de novo ablations, most ablations involved intracardiac echocardiography and electroanatomic mapping, but both were less common with CBA (87.3% vs. 93.9%, p

Guidelines recommend that initial trial of a "pill-in-the-pocket" (PIP) Class 1C antiarrhythmic drug (AAD) for cardioversion of atrial fibrillation (AF) be performed in a monitored setting because of the potential for adverse reactions.This study sought to characterize real-world, contemporary use of the PIP approach, including the setting of initiation and incidence of adverse events.This retrospective cohort study included all patients at the Hospital of the University of Pennsylvania treated with a PIP approach for AF between 2007 and 2020.A total of 273 patients (age 56 ± 13 years; 182 [67%] male; CHAOur data support the current recommendation to initiate PIP AAD in a monitored setting because of rare significant adverse reactions that can require urgent intervention.

BACKGROUND Ablation of septal substrate-associated ventricular tachycardia (VT) in patients with nonischemic cardiomyopathy (NICM) is challenging. We sought to standardize the characterization of septal substrates on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) and to examine the association of that substrate with VT exit and isthmus sites on invasive mapping. METHODS LGE-CMR was performed before electroanatomic mapping and ablation for VT in 20 NICM patients. LGE extent and distribution were quantified using myocardial signal-intensity Z scores (SI-Z). The SI-Z thresholds correlating to previously validated voltage thresholds, for abnormal tissue and dense scar were defined. RESULTS Bipolar and unipolar (electrogram) voltage amplitude measurements from the LV and RV were negatively associated with SI-Z from LGE-CMR imaging (p

Objectives This study sought to address whether technological innovations such as contact force sensing (CFS) can improve acute and long-term ablation outcomes of left ventricular papillar...

Background Twelve-lead electrocardiogram (ECG) criteria have been developed to identify idiopathic ventricular arrhythmias (VAs) from the left ventricular (LV) papillary muscles (PAPs), but accurate localization remains a challenge. Objective The purpose of this study was to develop ECG criteria for accurate localization of LV PAP VAs using lead V1 exclusively. Methods Consecutive patients undergoing mapping and ablation of VAs from the LV PAPs guided by intracardiac echocardiography from 2007 to 2018 were reviewed (study group). The QRS morphology in lead V1 was compared to patients with VAs with a "right bundle branch block" morphology from other LV locations (reference group). Patients with structural heart disease were excluded. Results One hundred eleven patients with LV PAP VAs (mean age 54 ± 16 years; 65% men) were identified, including 64 (55%) from the posteromedial PAP and 47 (42%) from the anterolateral PAP. The reference group included patients with VAs from the following LV locations: fascicles (n = 21), outflow tract (n = 36), ostium (n = 37), inferobasal segment (n = 12), and apex (5). PAP VAs showed 3 distinct QRS morphologies in lead V1 93% of the time: Rr (53%), R with a slurred downslope (29%), and RR (11%). Sensitivity, specificity, positive predictive value, and negative predictive value for the 3 morphologies combined are 93%, 98%, 98%, and 93%, respectively. The intrinsicoid deflection of PAP VAs in lead V1 was shorter than that of the reference group (63 ± 13 ms vs 79 ± 24 ms; P Conclusion VAs originating from the LV PAPs manifest unique QRS morphologies in lead V1, which can aid in rapid and accurate localization.

Background Early studies suggest that coronavirus disease 2019 (COVID-19) is associated with a high incidence of cardiac arrhythmias. SARS-CoV-2 infection may cause injury to cardiac myocytes and increase arrhythmia risk. Objective To evaluate the risk of cardiac arrest and arrhythmias including incident atrial fibrillation (AF), bradyarrhythmias, and nonsustained ventricular tachycardia (NSVT) in a large urban population hospitalized for COVID-19. We also evaluated correlations between the presence of these arrhythmias and mortality. Methods We reviewed the characteristics of all COVID-19 patients admitted to our center over a 9-week period. Throughout hospitalization, we evaluated the incidence of cardiac arrests, arrhythmias and in-patient mortality. We also used logistic regression to evaluate age, sex, race, body mass index, prevalent cardiovascular disease, diabetes, hypertension, kidney disease and ICU status as potential risk factors for each arrhythmia. Results Among 700 patients (mean age 50±18 years, 45% men, 71% African American, and 11% received ICU care), there were 9 cardiac arrests, 25 incident AF events, 9 clinically significant bradyarrhythmias, and 10 NSVTs. All cardiac arrests occurred among patients admitted to the ICU. In addition, admission to the ICU was associated with incident AF (OR 4.68 [95% CI 1.66 – 13.18]) and NSVT (OR 8.92 [95% CI 1.73 – 46.06]) after multivariable adjustment. Also, age and incident AF (OR 1.05 [95% CI 1.02 – 1.09]); and prevalent heart failure and bradyarrhythmias (OR 9.75 [95% CI 1.95 – 48.65]) were independently associated. Only cardiac arrests were associated with acute, in-hospital mortality. Conclusion Cardiac arrests and arrhythmias are likely the consequence of systemic illness and not solely the direct effects of COVID-19 infection., Graphical abstract

INTRODUCTION Functional tricuspid regurgitation (TR) remains a challenging clinical problem with poor outcomes and few effective treatments. Atrial fibrillation (AF) has been associated with functional TR. We sought to determine whether restoring sinus rhythm through catheter ablation of AF can decrease the degree of TR. METHODS AND RESULTS A retrospective cohort study of patients undergoing AF ablation between 2011 and 2017 at a single center was conducted. We included patients with at least moderate TR on echocardiogram within the year preceding ablation, who underwent repeat echocardiogram within the year following ablation. Formal quantitative analysis was performed by an experienced research echocardiographer, blinded to arrhythmia outcomes. Arrhythmia-free survival was correlated to the extent of improvement in TR. Thirty-six patients met the inclusion criteria. A baseline echocardiogram was performed 37 ± 68 days before ablation and follow-up echocardiogram 139 ± 112 days following ablation. Patients were 63.7 ± 11.1 years old with a mean CHA2 DS2 -VASc score of 2.7 ± 1.7. The degree of TR improved by at least one grade in 23 patients (64%). TR area decreased from 11.6 ± 3.4 to 7.0 ± 3.5 cm2 (p

Background Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are attractive for preventing sudden cardiac death in hypertrophic cardiomyopathy (HCM) as they mitigate risks of transvenous leads in young patients. However, S-ICDs may be associated with increased inappropriate shock (IAS) in HCM patients. Objective The purpose of this study was to assess the incidence and predictors of appropriate shock and IAS in a contemporary HCM S-ICD cohort. Methods We collected electrocardiographic and clinical data from HCM patients who underwent S-ICD implantation at 4 centers. Etiologies of all S-ICD shocks were adjudicated. We used Firth penalized logistic regression to derive adjusted odds ratios (aORs) for predictors of IAS. Results Eighty-eight HCM patients received S-ICDs (81 for primary and 7 for secondary prevention) with a mean follow-up of 2.7 years. Five patients (5.7%) had 9 IAS episodes (3.8 IAS per 100 patient-years) most often because of sinus tachycardia and/or T-wave oversensing. Independent predictors of IAS were higher 12-lead electrocardiographic R-wave amplitude (aOR 2.55 per 1 mV; 95% confidence interval 1.15–6.38) and abnormal T-wave inversions (aOR 0.16; 95% confidence interval 0.02–0.97). There were 2 appropriate shocks in 7 secondary prevention patients and none in 81 primary prevention patients, despite 96% meeting Enhanced American College of Cardiology/American Heart Association criteria and the mean European HCM Risk-SCD score predicting 5.7% 5-year risk. No patients had sudden death or untreated sustained ventricular arrhythmias. Conclusion In this multicenter HCM S-ICD study, IAS were rare and appropriate shocks confined to secondary prevention patients. The R-wave amplitude increased IAS risk, whereas T-wave inversions were protective. HCM primary prevention implantable cardioverter-defibrillator guidelines overestimated the risk of appropriate shocks in our cohort.

Objectives This study investigated the impact of the type of catheter irrigant used during delivery of radiofrequency ablation. Background The use of half-normal saline (HNS) as an irrigant has been suggested as a method for increasing ablation lesion size but has not been rigorously studied in the beating heart or the use of a low-flow irrigation catheter. Methods Sixteen swine underwent left ventricular mapping and ablation using either normal saline (NS) (group 1: n = 9) or half-normal saline (HNS) (group 2: n = 7). All lesions were delivered using identical parameters (40 W with 10-second ramp, 30-second duration, 15 ml/min flow, and 8- to14-g target contact force). An occurrence of steam pop, catheter char, or thrombus was assessed using intracardiac echocardiography and catheter inspection following each application. Lesion depth, width, and area were measured using electronic calibers. Results A total of 109 lesions were delivered in group 1 and 77 in group 2. There were significantly more steam pops in group 2 (32 of 77 [42%] vs. 24 of 109 [22%], respectively). The frequencies of catheter tip char were similar (group 1: 9 of 109 [8%] vs. group 2: 10 of 77 [13%]; p = 0.29). Lesion depths, widths, and areas also were similar in both groups. Conclusions The use of an HNS irrigant using a low-flow open irrigated ablation catheter platform results in more tissue heating due to higher radiofrequency current delivery directed to tissue, but this can lead to higher rate of steam pops. In this in vivo porcine beating-heart model, the use of HNS does not appear to significantly increase lesion size in normal myocardium despite evidence of increased radiofrequency heating.

Objectives This study investigated the prevalence and prognostic significance of concealed myocardial abnormalities identified by cardiac magnetic resonance (CMR) imaging in patients with apparently idiopathic premature ventricular contractions (PVCs). Background The role of CMR imaging in patients with frequent PVCs and otherwise negative diagnostic workup is uncertain. Methods This was a multicenter, international study that included 518 patients (44 ± 15 years; 57% men) with frequent (>1,000/24 h) PVCs and negative routine diagnostic workup. Patients underwent a comprehensive CMR protocol including late gadolinium enhancement imaging for detection of necrosis and/or fibrosis. The study endpoint was a composite of sudden cardiac death, resuscitated cardiac arrest, and nonfatal episodes of ventricular fibrillation or sustained ventricular tachycardia that required appropriate implantable cardioverter-defibrillator therapy. Results Myocardial abnormalities were found in 85 (16%) patients. Male gender (odds ratio [OR]: 4.28; 95% confidence interval [CI]: 2.06 to 8.93; p = 0.01), family history of sudden cardiac death and/or cardiomyopathy (OR: 3.61; 95% CI: 1.33 to 9.82; p = 0.01), multifocal PVCs (OR: 11.12; 95% CI: 4.35 to 28.46; p Conclusions CMR can identify concealed myocardial abnormalities in 16% of patients with apparently idiopathic frequent PVCs. Presence of myocardial abnormalities on CMR predict worse clinical outcomes.

In patients with nonischemic cardiomyopathy (NICM) little is known about the clinical impact of catheter ablation (CA) of septal ventricular tachycardia (VT) resulting in the collateral injury of the conduction system (CICS).Ninety-five consecutive patients with NICM underwent CA of septal VT. Outcomes in patients with no baseline conduction abnormalities who developed CICS (group 1, n = 28 [29%]) were compared to patients with no CICS (group 2, n = 17 [18%]) and to patients with preexisting conduction abnormalities or biventricular pacing (group 3, n = 50 [53%]). Group-1 patients were younger, had a higher left ventricular ejection fraction and a lower prevalence of New York Heart Association III/IV class compared to group 3 while no significant differences were observed with group 2. After a median follow-up of 15 months, VT recurred in 14% of patients in group 1, 12% in group 2 (P = .94) and 32% in group 3 (P = .08) while death/transplant occurred in 14% of patients in group 1, 18% in group 2 (P = .69) and 28% in group 3 (P = .15). A worsening of left ventricular ejection fraction (LVEF) (median LVEF variation, -5%) was observed in group 1 compared to group 2 (median LVEF variation, 0%; P .01) but not group-3 patients (median LVEF variation, -4%; P = .08) with a consequent higher need for new biventricular pacing in group 1 (43%) compared to group 2 (12%; P = .03) and group 3 (16%; P .01).In patients with NICM and septal substrate, sparing the abnormal substrate harboring the conduction system provides acceptable VT control while preventing a worsening of the systolic function.

Background Innominate vein stenosis and venous tortuosity are common findings during cardiac implantable electronic device upgrades or replacements and present a challenge to the implanting physician. Various techniques have been described to facilitate lead placement, including serial dilation, balloon venoplasty, and percutaneous access medial to the stenosis, each with its own benefits and risks. Objective The purpose of this study was to assess the feasibility, safety, and efficacy of the wire countertraction ("body flossing") technique to facilitate sheath placement through tortuous and stenotic vessels. Methods Patients undergoing cardiac implantable electronic device procedures requiring the body flossing technique due to inability to place vascular sheaths over the wire through stenoses or tortuosity were retrospectively analyzed. Clinical characteristics, procedural equipment, and outcomes were analyzed. Results Simultaneous countertraction was successful in all attempted cases, including 8 patients with stenoses and 2 with tortuosity. In 2 of the stenosis cases, venoplasty had previously failed. No complications occurred. Conclusion Simultaneous countertraction (body flossing) is an effective tool to overcome venous stenosis and tortuosity that are amenable to wire advancement but not to vascular sheaths. It seems to be a safe and effective alternative to other techniques used in these scenarios.

This study sought to examine clinical characteristics of procedural and long-term outcomes in patients undergoing catheter ablation (CA) of outflow tract ventricular arrhythmias (OT-VAs) over 16 years.CA is an effective treatment strategy for OT-VAs.Patients undergoing CA for OT-VAs from 1999 to 2015 were divided into 3 periods: 1999 to 2004 (early), 2005 to 2010 (middle), and 2011 to 2015 (recent). Successful ablation site (right ventricular OT, aortic cusps/left ventricular OT, or coronary venous system/epicardium), VA morphology (right bundle branch block or left bundle branch block), and acute and clinical success rates were assessed.Six hundred eighty-two patients (336 female) were included (early: n = 97; middle: n = 204; recent: n = 381). Over time there was increase in use of irrigated ablation catheters and electroanatomic mapping, and more VAs were ablated from the aortic cusp/left ventricular OT or coronary venous system/epicardium (14% vs. 45% vs. 56%; p 0.0001). Acute procedural success was achieved in 585 patients (86%) and was similar between groups (82% vs. 84% vs. 88%; p = 0.27). Clinical success was also similar between groups (86% vs. 87% vs. 88%; p = 0.94), but more patients in earlier periods required repeat ablation (18% vs. 17% vs. 9%; p = 0.02). Overall complication rate was 2% (similar between groups).Over a 16-year period there was an increase in patients undergoing CA for OT-VTs, with more ablations performed at non-right ventricular outflow tract locations using electroanatomic mapping and irrigated-tip catheters. Over time, single procedure success has improved and complications have remained limited.