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Current therapies for pulmonary vein stenosis (PVS) or pulmonary vein total occlusion (PVTO) involving angioplasty and stenting are hindered by high rates of restenosis.

Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular substrate modification (FSM) approaches have been suggested to treat recurrent VF in case reports and small case series.

Epicardial (Epi) access is commonly required during ventricular tachycardia ablation. Conventional Epi (ConvEpi) access targets a “dry” pericardial space presenting technical challenges and risk of complications. Recently, intentional puncture of coronary venous branches with Epi carbon dioxide insufflation (EpiCO2) has been described as a technique to improve Epi access. The safety of this technique relative to conventional methods remains unproven.

Wildlife and zoonotic diseases are increasingly impacting human society, the food chain, and wildlife; therefore, proactive mitigation tools for predicting large-scale risk of the relevant pathogens are urgently needed. Birds and bats are large-scale disease reservoirs and transmitters. However, holistic understanding for which bird and bat species act as reservoirs for pathogens remains understudied. Here, we test the extent to which the features related to the mobile species and local climate identify reservoir hosts for the 18 most-sampled pathogens across Europe. Species with slower pace of life (i.e., larger bodied and longer lived), sedentary species, and forest species had high pathogen prevalence. Temperature was the most important predictor for pathogen prevalence, but its effects varied in different directions. Overall, host species traits and climatic gradients robustly predicted pathogen prevalence, especially for non-vector-transmitted pathogens. We offer a data-driven basis for developing targeted interventions to mitigate impacts of zoonotic diseases, particularly in the face of climate change.

Implantable cardioverter‐defibrillator (ICD) offers an opportunity to study inducibility of ventricular tachycardia (VT) or ventricular fibrillation (VF) by performing noninvasive programmed ventricular stimulation (NIPS). Whether NIPS can predict future arrhythmic events or mortality in patients with primary prevention ICD, has not yet been examined. From the NIPS‐ICD study (ClinicalTrials ID: NCT02373306) 41 consecutive patients (34 males, age 64 ± 11 years, 76% ischemic cardiomyopathy [ICM]) had ICD for primary prevention indication. Patients underwent NIPS using a standardized protocol of up to three premature extrastimuli at 600, 500 and 400 ms drive cycle lengths. NIPS was classified as positive if sustained VT or VF was induced. The study endpoint was occurrence of sustained VT/VF during the follow‐up. At baseline NIPS, VT/VF was induced in 8 (20%) ICM patients. During the 5‐year follow‐up, the VT/VF occurred in 7 (17%) patients, all with ICM. The difference between NIPS‐inducible versus NIPS‐noninducible patients regarding VT/VF occurrence did not meet statistical significance (38% vs. 12%, log rank test p= .11). After a 5‐year follow‐up, the mortality rate was significantly higher in patients who had VT/VF induced at NIPS versus no VT/VF at NIPS (38% vs. 12%, p= .043). The occurrence of a composite endpoint consisting of VT/VF recurrence or death in patients with ICM was also most frequent in the NIPS‐inducible group (75% vs. 35%, p= .037). Inducibility of VT/VF during NIPS in ICM patients with primary prevention ICD is associated with higher mortality and higher incidence of composite endpoint consisting of death or VT/VF during a long‐term observation. Whether NIPS can predict future arrhythmic events or mortality in patients with primary prevention ICD, has not yet been examined. The NIPS‐ICD study indicates that inducibility of VT/VF during NIPS in patients with primary prevention ICD is associated with higher mortality and higher incidence of composite endpoint consisting of death or VT/VF during a long‐term observation.

In patients with structural heart disease and ventricular tachycardia (VT) undergoing catheter ablation, the response to programmed electrical stimulation (PES) at the end of the procedure has been traditionally used to evaluate the acute success and predict long-term outcomes. Although noninducibility at PES has been extensively investigated and validated in clinical trials and large multicenter registries, its performance in predicting long-term freedom from VT is suboptimal. In addition, PES has inherent limitations related to the influence of background antiarrhythmic drug therapy, periprocedural use of anesthesia, and the heterogeneity in PES protocols. The increased utilization of substrate-based ablation approaches that focus on ablation of abnormal electrograms identified with mapping in sinus or paced rhythm has been paralleled by a need for additional procedural endpoints beyond VT noninducibility at PES. This article critically appraises the relative merits and limitations of different procedural endpoints according to different ablation techniques for catheter ablation of scar-related VT.

The efficacy of pulsed field ablation (PFA) for redo procedures is unknown.

Entrainment and pace mapping are used to identify critical components (CCs) of ventricular tachycardia (VT) circuits. In patients with dense myocardial scarring, VT circuits may elude capture at standard high pacing outputs (up to 10 mA at a 2-millisecond pulse width).

Targeting nonpulmonary vein triggers (NPVTs) of atrial fibrillation (AF) after pulmonary vein isolation can be challenging. NPVTs are often single ectopic beats with a surface P-wave obscured by a QRS or T-wave.

Monomorphic ventricular tachycardia (VT) electrical storm (ES) in patients with coronary artery disease is dependent on scarred myocardium. The role of routine ischemic or coronary evaluations before ablation in patients presenting with monomorphic VT storm, without acute coronary syndrome (ACS), remains unknown.

Intraprocedural identification of intramural septal substrate for ventricular tachycardia (ISS-VT) in nonischemic cardiomyopathy (NICM) is challenging. Delayed (>40 ms) transmural conduction time (DCT) with right ventricular basal septal pacing has been previously shown to identify ISS-VT.

In the setting of structural heart disease, ventricular tachycardia (VT) is typically associated with a re-entrant mechanism. In patients with hemodynamically tolerated VTs, activation and entrainment mapping remain the gold standard for the identification of the critical parts of the circuit. However, this is rarely accomplished, as most VTs are not hemodynamically tolerated to permit mapping during tachycardia. Other limitations include noninducibility of arrhythmia or nonsustained VT. This has led to the development of substrate mapping techniques during sinus rhythm, eliminating the need for prolonged periods of mapping during tachycardia. Recurrence rates following VT ablation are high; therefore, new mapping techniques for substrate characterization are required. Advances in catheter technology and especially multielectrode mapping of abnormal electrograms has increased the ability to identify the mechanism of scar-related VT. Several substrate-guided approaches have been developed to overcome this, including scar homogenization and late potential mapping. Dynamic substrate changes are mainly identified within regions of myocardial scar and can be identified as local abnormal ventricular activities. Furthermore, mapping strategies incorporating ventricular extrastimulation, including from different directions and coupling intervals, have been shown to increase the accuracy of substrate mapping. The implementation of extrastimulus substrate mapping and automated annotation require less extensive ablation and would make VT ablation procedures less cumbersome and accessible to more patients.

Venous ethanol ablation (VEA) can be effective for ventricular arrhythmias from the left ventricular summit (LVS); however, there are concerns about excessive ablation by VEA.

High-power, short-duration (HPSD) radiofrequency ablation (RFA) may reduce ablation time. Concerns that catheter-mounted thermocouples (TCs) can underestimate tissue temperature, resulting in elevated risk of steam pop formation, potentially limit widespread adoption of HPSD ablation.

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.

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.

Post–myocardial infarction ventricular tachycardia (VT) is due to re-entry through surviving conductive myocardial corridors across infarcted tissue. However, not all conductive corridors participate in re-entry.

Background: Implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden cardiac death have been proven effective in several clinical trials. Purpose: To summarize evidence about the effectiveness of ICDs versus standard medical therapy for the primary prevention of sudden cardiac death in different age groups of patients with severe left ventricular dysfunction. Data Sources: MEDLINE, Embase, CENTRAL, BioMed Central, Cardiosource, ClinicalTrials.gov, and ISI Web of Science (January 1970 to April 2010) were searched with no language restrictions. Study Selection: Two independent reviewers screened titles and abstracts to identify randomized, controlled trials of prophylactic ICD versus medical therapy in patients with severe left ventricular dysfunction that provided data about mortality outcomes for different age groups. Data Extraction: Two independent reviewers assessed risk for bias of trials and extracted patient and study characteristics and hazard ratios (HRs) relevant to all-cause mortality. Data Synthesis: Five trials (MADIT-II, DEFINITE, DINAMIT, SCDHEFT, and IRIS) that enrolled 5783 patients (44% were elderly) were included. The primary analysis, which excluded the 2 trials enrolling patients early after acute myocardial infarction (DINAMIT and IRIS), found that prophylactic ICD therapy reduced mortality in younger patients (HR, 0.65 [95% CI, 0.50 to 0.83]; P < 0.001). A smaller and statistically nonsignificant survival benefit was found in elderly patients (HR, 0.81 [CI, 0.62 to 1.05]; P = 0.11). The inclusion of data from DINAMIT and IRIS did not change these results. Limitations: Four potentially eligible trials were not included in the meta-analysis because mortality data by age group were not available. Adjustment for differences in comorbid conditions and medical therapies among patients enrolled in the trials was not possible. Conclusion: Available data do not conclusively show that prophylactic ICD therapy improves survival in elderly patients with severe left ventricular dysfunction. Primary Funding Source: None.

This study sought to explore whether prolonged duration (PD) radiofrequency ablation (RFA) from adjacent endocardial locations can improve catheter ablation (CA) outcomes of left ventricular summit (LVS) ventricular arrhythmias (Vas).

IMPORTANCE: Ventricular tachycardia (VT) is associated with high mortality in patients with cardiac sarcoidosis (CS), and medical management of CS-associated VT is limited by high failure rates. The role of catheter ablation has been investigated in small, single-center studies. OBJECTIVE: To investigate outcomes associated with VT ablation in patients with CS. DESIGN, SETTING, AND PARTICIPANTS: This cohort study from the Cardiac Sarcoidosis Consortium registry (2003-2019) included 16 tertiary referral centers in the US, Europe, and Asia. A total of 158 consecutive patients with CS and VT were included (33% female; mean [SD] age, 52 [11] years; 53% with ejection fraction [EF] &lt;50%). EXPOSURES: Catheter ablation of CS-associated VT and, as appropriate, medical treatment. MAIN OUTCOMES AND MEASURES: Immediate and short-term outcomes included procedural success, elimination of VT storm, and reduction in defibrillator shocks. The primary long-term outcome was the composite of VT recurrence, heart transplant (HT), or death. RESULTS: Complete procedural success (no inducible VT postablation) was achieved in 85 patients (54%). Sixty-five patients (41%) had preablation VT storm that did not recur postablation in 53 (82%). Defibrillator shocks were significantly reduced from a median (IQR) of 2 (1-5) to 0 (0-0) in the 30 days before and after ablation (P &lt; .001). During median (IQR) follow-up of 2.5 (1.1-4.9) years, 73 patients (46%) experienced VT recurrence and 81 (51%) experienced the composite primary outcome. One- and 2-year rates of survival free of VT recurrence, HT, or death were 60% and 52%, respectively. EF less than 50% and myocardial inflammation on preprocedural 18F-fluorodeoxyglucose positron emission tomography were significantly associated with adverse prognosis in multivariable analysis for the primary outcome (HR, 2.24; 95% CI, 1.37-3.64; P = .001 and HR, 2.93; 95% CI, 1.31-6.55; P = .009, respectively). History of hypertension was associated with a favorable long-term outcome (adjusted HR, 0.51; 95% CI, 0.28-0.92; P = .02). CONCLUSIONS AND RELEVANCE: In this observational study of selected patients with CS and VT, catheter ablation was associated with reductions in defibrillator shocks and recurrent VT storm. Preablation LV dysfunction and myocardial inflammation were associated with adverse long-term prognosis. These data support the role of catheter ablation in conjunction with medical therapy in the management of CS-associated VT.

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It remains unclear whether additional left atrial posterior wall isolation (LAPWI) beyond pulmonary vein reisolation (PVRI) is beneficial in atrial fibrillation (AF) patients undergoing repeat ablation.

The MgGeO3system is a low-pressure analog for the Earth-forming (Mg,Fe)SiO3system and exhibits recoverable orthopyroxene, clinopyroxene, and ilmenite structures below 6 GPa. The pressure-temperature conditions of the clinopyroxene to ilmenite phase transition are reasonably consistent between studies, having a positive Clapeyron slope and occurring between 4 and 7 GPa in the temperature range 900–1600 K. There are, though, significant discrepancies in the Clapeyron slope of the orthopyroxene to clinopyroxene phase transition in existing works that also disagree on the stable phase at ambient conditions. The most significant factor in these differences is the method used; high-pressure experiments and thermophysical property measurements yield apparently contradicting results. Here, we perform both high pressure and temperature experiments as well as thermal expansion measurements to reconcile the measurements. High-pressure and -temperature experiments yield a Clapeyron slope of –1.0–+1.0-0.7MPa/K for the MgGeO3orthopyroxene-clinopyroxene phase transition, consistent with previous high-pressure and -temperature experiments. The MgGeO3orthopyroxene-clinopyroxene-ilmenite triple point is determined to be at 0.98 GPa and 752 K, with the ilmenite phase stable at ambient conditions. The high-temperature (>600 K) thermal expansion of the clinopyroxene phase is greater than that of the other phases. Debye-Grüneisen relationships fitted to the volume-temperature data give Debye temperatures for the orthopyroxene, clinopyroxene, and ilmenite phases of 602(7), 693(10), and 758(13) K and V0of 897.299(16), 433.192(10), and 289.156(6) Å3, respectively. The Clapeyron slopes calculated directly from the Debye-Grüneisen relationships are consistent with previous thermophysical property measurements. The presence of significant anharmonicity and/or formation of defects in the clinopyroxene phase at high-temperatures, which is not apparent in the other phases, accounts for the previous contradictions between studies. The inferred increased heat capacity of the clinopyroxene corresponds to an increase in entropy and an expanded phase field at high temperatures.

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.

IMPORTANCE: In patients with mechanical valves in the aortic and mitral positions, percutaneous access to the left ventricle (LV) via a transfemoral approach for catheter ablation of ventricular tachycardia (VT) has been considered infeasible. OBJECTIVE: To describe the outcomes of a novel percutaneous trans–right atrial (RA) access to the LV via a femoral venous approach for catheter ablation of VT in patients with mechanical aortic and mitral valves. DESIGN, SETTING, AND PARTICIPANTS: This observational study included consecutive patients with mechanical valves in the aortic and mitral positions and recurrent monomorphic drug-refractory VT associated with an LV substrate. Percutaneous LV access was performed from a transfemoral venous route with the aid of a deflectable sheath and a radiofrequency wire by creating an iatrogenic Gerbode defect with direct puncture of the inferior and medial aspect of the RA, adjacent to the inferior-septal process of the LV (ISP-LV), under intracardiac echography guidance. Once the wire crossed to the LV, balloon dilatation of the ventriculotomy site (with a noncompliant balloon; diameter, 8 to 10 mm) was performed to facilitate passage of the sheath within the LV. EXPOSURES: Percutaneous trans-RA access to the LV via puncture of the ISP-LV to perform catheter ablation of VT in patients with mechanical aortic and mitral valves. MAIN OUTCOMES AND MEASURES: Feasibility and safety of a trans-RA access to the LV for catheter ablation of VT. RESULTS: A total of 4 patients (mean [SD] age, 60 [7] years; mean [SD] LV ejection fraction, 31% [9%]) with recurrent VT associated with an LV substrate (ischemic cardiomyopathy, 3 patients; nonischemic cardiomyopathy, 1 patient) and mechanical valves in the aortic and mitral position underwent trans-RA access through the ISP-LV for catheter ablation of VT. The time to obtain LV access ranged from 60 minutes (first case) to 22 minutes (last case) (mean [SD], 36 [15] minutes). No complications associated with the access occurred. In particular, in the 3 patients with preserved atrioventricular conduction at baseline, no new conduction abnormalities were observed after the access. Complete VT noninducibility at programmed ventricular stimulation was achieved in 3 cases, and no patient had VT recurrence at a median follow-up of 14 months (range, 6-21 months). CONCLUSIONS AND RELEVANCE: A percutaneous trans-RA access to the LV via a femoral venous approach for catheter ablation of VT in patients with mechanical aortic and mitral valves is feasible and appears safe. This novel technique may allow for catheter ablation of VT in a population of patients in whom conventional LV access via retrograde aortic or atrial transseptal routes is not possible.

In this study the authors hypothesized that “Lean management” within a dedicated ablation protocol could standardize the pulmonary vein isolation (PVI) procedure and improve quality.

This study sought to examine the impact of periprocedural acute kidney injury (AKI) in scar-related ventricular tachycardia (VT) patients undergoing radiofrequency catheter ablation (RFCA) on short- and long-term outcomes.

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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 papillary muscle (LV PAP) ventricular arrhythmias (VAs).

This study aimed to characterize the incidence, clinical characteristics, and electrocardiographic and electrophysiologic features of LVA VA in the absence of CAD and to describe the experience with catheter ablation (CA) in this group.

This study investigated the impact of the type of catheter irrigant used during delivery of radiofrequency ablation.

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).

This study describes the technique and outcomes of atrial fibrillation (AF) ablation via a superior approach in patients with interrupted or absent inferior vena cavas (IVCs).

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRSExpert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta‐analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow‐up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

This study sought to evaluate the prevalence, mapping features, and ablation outcomes of non–scar-related ventricular tachycardia (NonScar-VT) and Purkinje-related VT (Purkinje-VT) in patients with structural heart disease.

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.

This study sought to compare efficacy and safety of the septal mitral isthmus line (SMIL) with that of the lateral mitral isthmus line (LMIL) for treatment of mitral annular flutter (MAF).

This article has been withdrawn because it is a duplicate. The correct published version of the article can be found at http://dx.doi.org/10.1016/j.jacep.2015.03.005. The Publisher apologizes for any inconvenience this may cause.

Long-term rhythm monitoring to detect atrial fibrillation (AF) following a cryptogenic stroke (CS) is well established. However, the burden of organized atrial arrhythmias in this population is not well defined.

This study sought to characterize ventricular arrhythmia (VA) ablated from the basal inferoseptal left ventricular endocardium (BIS-LVe) and identify electrocardiographic characteristics to differentiate from inferobasal crux (IBC) VA.

This study sought to assess the performance of established risk models in predicting outcomes after catheter ablation (CA) in patients with nonischemic dilated cardiomyopathy (NIDCM) and ventricular tachycardia (VT).

This study describes the use of septal coronary venous mapping to facilitate substrate characterization and ablation of intramural septal ventricular arrhythmia (VA).

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRSExpert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta‐analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow‐up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

This study sought to determine the impact of repeat catheter ablation (CA) prior to hospital discharge based on inducibility of clinical ventricular tachycardia (VT) during noninvasive programmed ventricular stimulation (NIPS).