Multicenter experience with andexanet alfa for refractory pericardial bleeding during catheter ablation of atrial fibrillation.

INTRODUCTION: 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. METHODS AND RESULTS: In this multicenter, case series, participating centers identified patients who received a dose of apixaban or rivaroxaban within 24 h 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 CHA2 DS2 -VASc score 4 [3-5]. All patients received protamine and pericardiocentesis, and 9 (82%) received blood products. All patients received a bolus of andexanet followed, in all but one, by a 2-h infusion. Acute hemostasis was achieved in eight patients (73%) while three required emergent surgery. One patient (9%) experienced acute ST-elevation myocardial infarction after receiving andexanet. Therapeutic AC was restarted after a mean of 2.2 ± 1.9 days and oral AC was restarted after a mean of 2.9 ± 1.6 days, with no recurrent bleeding. CONCLUSION: In 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.

Evaluating temperature gradients across the posterior left atrium with radiofrequency ablation.

INTRODUCTION: Esophageal injury is a well-known complication associated with catheter ablation. Though novel methods to mitigate esophageal injury have been developed, few studies have evaluated temperature gradients with catheter ablation across the posterior wall of the left atrium, interstitium, and esophagus. METHODS: To investigate temperature gradients across the tissue, we developed a porcine heart-esophageal model to perform ex vivo catheter ablation on the posterior wall of the left atrium (LA), with juxtaposed interstitial tissue and esophagus. Circulating saline (5 L/min) was used to mimic blood flow along the LA and alteration of ionic content to modulate impedance. Thermistors along the region of interest were used to analyze temperature gradients. Varying time and power, radiofrequency (RF) ablation lesions were applied with an externally irrigated ablation catheter. Ablation strategies were divided into standard approaches (SAs, 10-15 g, 25-35 W, 30 s) or high-power short duration (HPSD, 10-15 g, 40-50 W, 10 s). Temperature gradients, time to the maximum measured temperature, and the relationship between measured temperature as a function of distance from the site of ablation was analyzed. RESULTS: In total, five experiments were conducted each utilizing new porcine posterior LA wall-esophageal specimens for RF ablation (n = 60 lesions each for SA and HPSD). For both SA and HPSD, maximum temperature rise from baseline was markedly higher at the anterior wall (AW) of the esophagus compared to the esophageal lumen (SA: 4.29°C vs. 0.41°C, p < .0001 and HPSD: 3.13°C vs. 0.28°C, p < .0001). Across ablation strategies, the average temperature rise at the AW of the esophagus was significantly higher with SA relative to HPSD ablation (4.29°C vs. 3.13°C, p = .01). From the start of ablation, the average time to reach a maximum temperature as measured at the AW of the esophagus with SA was 36.49 ± 12.12 s, compared to 16.57 ± 4.54 s with HPSD ablation, p < .0001. Fit to a linear scale, a 0.37°C drop in temperature was seen for every 1 cm increase in distance from the site of ablation and thermistor location at the AW of the esophagus. CONCLUSION: Both SA and HPSD ablation strategies resulted in markedly higher temperatures measured at the AW of the esophagus compared to the esophageal lumen, raising concern about the value of clinical intraluminal temperature monitoring. The temperature rise at the AW was lower with HPSD. A significant time delay was seen to reach the maximum measured temperature and a modest increase in distance between the site of ablation and thermistor location impacted the accuracy of monitored temperatures.

PRIME score for prediction of permanent pacemaker implantation after transcatheter aortic valve replacement.

OBJECTIVES: We sought to produce a simple scoring system that can be applied at clinical visits before transcatheter aortic valve replacement (TAVR) to stratify the risk of permanent pacemaker (PPM) after the procedure. BACKGROUND: Atrioventricular block is a known complication of TAVR. Current models for predicting the risk of PPM after TAVR are not designed to be applied clinically to assist with preprocedural planning. METHODS: Patients undergoing TAVR at the University of Colorado were split into a training cohort for the development of a predictive model, and a testing cohort for model validation. Stepwise and binary logistic regressions were performed on the training cohort to produce a predictive model. Beta coefficients from the binary logistic regression were used to create a simple scoring system for predicting the need for PPM implantation. Scores were then applied to the validation cohort to assess predictive accuracy. RESULTS: Patients undergoing TAVR from 2013 to 2019 were analyzed: with 483 included in the training cohort and 123 included in the validation cohort. The need for a pacemaker was associated with five preprocedure variables in the training cohort: PR interval > 200 ms, Right bundle branch block, valve-In-valve procedure, prior Myocardial infarction, and self-Expandable valve. The PRIME score was developed using these clinical features, and was highly accurate for predicting PPM in both the training and model validation cohorts (area under the curve 0.804 and 0.830 in the model training and validation cohorts, respectively). CONCLUSIONS: The PRIME score is a simple and accurate preprocedural tool for predicting the need for PPM implantation after TAVR.

Design and characteristics of the prophylactic intra-operative ventricular arrhythmia ablation in high-risk LVAD candidates (PIVATAL) trial.

BACKGROUND: The use of a Left Ventricular Assist Device (LVAD) in patients with advanced heart failure refractory to optimal medical management has progressed steadily over the past two decades. Data have demonstrated reduced LVAD efficacy, worse clinical outcome, and higher mortality for patients who experience significant ventricular tachyarrhythmia (VTA). We hypothesize that a novel prophylactic intra-operative VTA ablation protocol at the time of LVAD implantation may reduce the recurrent VTA and adverse events postimplant. METHODS: We designed a prospective, multicenter, open-label, randomized-controlled clinical trial enrolling 100 patients who are LVAD candidates with a history of VTA in the previous 5 years. Enrolled patients will be randomized in a 1:1 fashion to intra-operative VTA ablation (n = 50) versus conventional medical management (n = 50) with LVAD implant. Arrhythmia outcomes data will be captured by an implantable cardioverter defibrillator (ICD) to monitor VTA events, with a uniform ICD programming protocol. Patients will be followed prospectively over a mean of 18 months (with a minimum of 9 months) after LVAD implantation to evaluate recurrent VTA, adverse events, and procedural outcomes. Secondary endpoints include right heart function/hemodynamics, healthcare utilization, and quality of life. CONCLUSION: The primary aim of this first-ever randomized trial is to assess the efficacy of intra-operative ablation during LVAD surgery in reducing VTA recurrence and improving clinical outcomes for patients with a history of VTA.

Procedural and short-term results of electroanatomic-mapping-guided ganglionated plexus ablation by first-time operators: A multicenter study.

INTRODUCTION: Single-center observational studies have shown promising results with fragmented electrogram (FE)-guided ganglionated plexus (GP) ablation in patients with vagally mediated bradyarrhythmia (VMB). We aimed to compare the acute procedural characteristics during FE-guided GP ablation in patients with VMB performed by first-time operators and those of a single high-volume operator. METHODS AND RESULTS: This international multicenter cohort study included data collected over 2 years from 16 cardiac hospitals. The primary operators were classified according to their prior GP ablation experience: a single high-volume operator who had performed > 50 GP ablation procedures (Group 1), and operators performing their first GP ablation cases (Group 2). Acute procedural characteristics and syncope recurrence were compared between groups. Forty-seven consecutive patients with VMB who underwent FE-guided GP ablation were enrolled, n = 31 in Group 1 and n = 16 in Group 2. The mean number of ablation points in each GP was comparable between groups. The ratio of positive vagal response during ablation on the left superior GP was higher in Group 1 (90.3% vs. 62.5%, p = .022). Ablation of the right superior GP increased heart rate acutely without any vagal response in 45 (95.7%) cases. The procedure time was longer in group 2 (83.4 ± 21 vs. 118.0 ± 21 min, respectively, p < .001). Over a mean follow-up duration of 8.0 ± 3 months (range 2-24 months), none of the patients suffered from syncope. CONCLUSION: This multi-center pilot study shows for the first time the feasibility of FE-guided GP ablation across a large group of procedure-naïve operators.

Evaluation of a novel cardiac signal processing system for electrophysiology procedures: The PURE EP 2.0 study.

BACKGROUND: Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has known shortcomings and has not advanced in several decades. OBJECTIVE: The purpose of this study was to evaluate a new signal processing platform, the PURE EP™ system (PURE), in a multi-center, prospective study. METHODS: Intracardiac signal data of clinical interest were collected from 51 patients undergoing ablation procedures with PURE, the signal recording system, and the 3D mapping system at the same time stamps. The samples were randomized and subjected to blinded, controlled evaluation by three independent electrophysiologists to determine the overall quality and clinical utility of PURE signals when compared to conventional sources. Each reviewer assessed the same (92) signal sample sets and responded to (235) questions using a 10-point rating scale. If two or more reviewers rated the PURE signal higher than the control, it was deemed superior. RESULTS: A total of 93% of question responses showed consensus amongst the blinded reviewers. Based on the ratings for each pair of signals, a cumulative total of 164 PURE signals out of 218 (75.2%) were statistically rated as Superior for this data set (p < .001). Only 14 PURE signals out of 218 were rated as Inferior (6.4%). CONCLUSION: The PURE intracardiac signals were statistically rated as superior when compared to conventional systems.

Catheter ablation of ventricular tachycardia in patients with prior cardiac surgery: An analysis from the International VT Ablation Center Collaborative Group.

INTRODUCTION: Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation. METHODS: We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival. RESULTS: There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p < .01), with lower left ventricular ejection fraction (30.2 ± 11.5% vs. 34.8 ± 13.6%, p < .01) and more ischemic heart disease (82.5% vs. 39.3%, p < .01) but less likely to undergo epicardial mapping or ablation (9.0% vs. 38.1%, p<.01) compared to those without prior surgery. When epicardial mapping was performed, a significantly greater proportion required surgical intervention for access (19/52 [36.5%] vs. 14/504 [2.8%]; p < .01). Procedural complications, including epicardial access-related complications, were lower (5.7% vs. 7.0%, p < .01) in patients with versus without prior cardiac surgery. VT-free survival (75.1% vs. 74.1%, p = .805) and survival (86.5% vs. 87.9%, p = .397) were not different between those with and without prior heart surgery, regardless of etiology of cardiomyopathy. VT recurrence was associated with increased mortality in patients with and without prior cardiac surgery. CONCLUSION: Despite different clinical characteristics and fewer epicardial procedures, the safety and efficacy of VT ablation in patients with prior cardiac surgery is similar to others in this cohort. The incremental yield of epicardial mapping in predominant ischemic cardiomyopathy population prior heart surgery may be low but appears safe in experienced centers.

Uncovering a unique path: Antidromic AVRT utilizing a left anteroseptal Mahaim-like accessory pathway.

A 40-year-old man presented to our emergency department 2 hours after onset of shortness of breath, palpitations, and presyncope secondary to an adenosine-responsive wide complex tachycardia. Electrophysiology study was diagnostic for antidromic atrioventricular (AV) reentrant tachycardia utilizing a muscular connection from the anterior interventricular vein to the left ventricle with Mahaim-like properties, successfully treated with ablation in the distal coronary sinus (CS) system. This case highlights accessory pathways (a) with unique features (i.e., Mahaim-like characteristics) and (b) involving musculature from the distal CS system, thereby limiting the value of endocardial ablation for durable treatment. Importantly, the coronary venous system is an accessible vascular network for evaluation and catheter ablation of such arrhythmias.

A Disruptive Technology: Determining Need for Permanent Pacing After TAVR.

PURPOSE OF REVIEW: Transcatheter aortic valve replacement (TAVR) has changed the paradigm for management of severe aortic stenosis. Despite evolution of TAVR over the past 2 decades, conduction system disturbances remain a concern post-TAVR. In this review, we describe (1) permanent pacemaker (PP) implant rates associated with TAVR, (2) risk factors predicting need for PP therapy post-TAVR, (3) management of perioperative conduction abnormalities, and (4) novel areas of research. RECENT FINDINGS: Conduction disturbances remain a common issue post-TAVR, in particular, left bundle branch block (LBBB). Though newer data describes resolution of a significant fraction of these disturbances over time, rates of pacemaker therapy remain high despite improvements in valve technology and procedural technique. Recent consensus statements and guideline documents are important first steps in standardizing an approach to post-TAVR conduction disturbances. New areas of research show promise in both prediction and treatment of conduction disturbances post-TAVR.

Electrophysiologic Implications of Transcatheter Aortic Valve Replacement: Incidence, Outcomes, and Current Management Strategies.

PURPOSE OF REVIEW: Transcatheter aortic valve replacement (TAVR) has changed the paradigm for management of severe aortic stenosis. Despite substantial procedural advancements, conduction system abnormalities remain a common complication following TAVR. In this review, we describe (1) incidence and risk factors for the development of conduction disturbances following TAVR, along with their prognostic significance, (2) the incidence and prognostic significance of new-onset arrhythmias following TAVR, (3) approach to management of perioperative and post-procedural conduction disturbances and arrhythmias, and (4) novel areas of research. RECENT FINDINGS: Conduction disturbances including left bundle branch block (LBBB) and high-grade atrioventricular block (HAVB) remain common issues post-TAVR despite advancements in valve technology and improvements in procedural technique. Despite data showing most conduction abnormalities resolve over time, rates of post-procedural permanent pacemaker implantation remain high. Similarly, rates of new-onset or newly detected arrhythmia, particularly atrial fibrillation, have been widely reported post-implantation of all types of TAVR valves. Recent consensus statements and decision pathway documents have been helpful in standardizing an approach to post-TAVR conduction disturbances. New areas of research show promise both for predicting which patients will develop conduction disturbances post-TAVR and for management of HAVB with novel pacing techniques. On the other hand, management of new-onset or newly detected atrial fibrillation after TAVR remains a significant challenge without standardized treatment strategy.

A multicenter trial of a shared DECision Support Intervention for Patients offered implantable Cardioverter-DEfibrillators: DECIDE-ICD rationale, design, Medicare changes, and pilot data.

Shared decision making (SDM) facilitates delivery of medical therapies that are in alignment with patients' goals and values. Medicare national coverage decision for several interventions now includes SDM mandates, but few have been evaluated in nationwide studies. Based upon a detailed needs assessment with diverse stakeholders, we developed pamphlet and video patient decision aids (PtDAs) for implantable cardioverter/defibrillator (ICD) implantation, ICD replacement, and cardiac resynchronization therapy with defibrillation to help patients contemplate, forecast, and deliberate their options. These PtDAs are the foundation of the Multicenter Trial of a Shared Decision Support Intervention for Patients Offered Implantable Cardioverter-Defibrillators (DECIDE-ICD), a multicenter, randomized trial sponsored by the National Heart, Lung, and Blood Institute aimed at understanding the effectiveness and implementation of an SDM support intervention for patients considering ICDs. Finalization of a Medicare coverage decision mandating the inclusion of SDM for new ICD implantation occurred shortly after trial initiation, raising novel practical and statistical considerations for evaluating study end points. METHODS/DESIGN: A stepped-wedge randomized controlled trial was designed, guided by the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) planning and evaluation framework using an effectiveness-implementation hybrid type II design. Six electrophysiology programs from across the United States will participate. The primary effectiveness outcome is decision quality (defined by knowledge and values-treatment concordance). Patients with heart failure who are clinically eligible for an ICD are eligible for the study. Target enrollment is 900 participants. DISCUSSION: Study findings will provide a foundation for implementing decision support interventions, including PtDAs, with patients who have chronic progressive illness and are facing decisions involving invasive, preference-sensitive therapy options.

Impact of epicardial adipose tissue and catheter ablation strategy on biophysical parameters and ablation lesion characteristics.

BACKGROUND: Epicardial adipose (EA) tissue may limit effective radiofrequency ablation (RFA). OBJECTIVES: We sought to evaluate the lesion formation of different ablation strategies on ventricular myocardium with overlying EA. METHODS: Bovine myocardium with EA was placed in a circulating saline bath in an ex vivo model. Open-irrigated (OI) RFA was performed, parallel to the myocardium, over fat at 50 W for variable RF durations, variable contact force, catheter configurations (unipolar RF vs bipolar RF), and catheter irrigants (normal saline vs half-normal saline). Ablation was also performed with a needle-tipped ablation catheter (NTAC), perpendicular to the myocardium. RESULTS: Increasingly thick EA attenuated lesion size regardless of ablation strategy. RF applied with longer durations and increasing CF produced larger lesion volumes and deeper lesions with ablation over EA more than 3 mm but was unable to produce measurable lesions when EA less than 3 mm. Similarly, ablation with half normal saline irrigant created slightly deeper lesions than bipolar RF and unipolar RF with normal saline as EA thickness increased, but was unable to produce measurable lesions when EA more than 3 mm. Of all ablation strategies, only NTAC produced effective lesion volumes when ablating over thick (>3 mm) EA. CONCLUSIONS: While EA attenuates lesion depth and size, relatively larger, and deeper lesions can be achieved with longer RFA duration, higher CF, half normal saline irrigant, and, to a greater extent, by utilizing bipolar RF or NTAC, but only over thin adipose (<3 mm). Of those catheters/strategies tested, only NTAC was able to effectively deliver RF over thick (>3 mm) EA with this model.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias: executive summary.

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/HRS Expert 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.

Implantable cardioverter-defibrillators in cardiac transplant recipients: A systematic review from the Electrophysiology Collaborative Consortium for Meta-analysis-ELECTRAM investigators.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) in patients with heart failure with reduced ejection fraction reduces mortality secondary to malignant arrhythmias. Whether cardiac transplant patients considered high risk for sudden death (SD) derive similar benefits remains controversial. METHODS: Systematic search, without language restriction, using PubMed, EMBASE, SCOPUS, Google Scholar, and ClinicalTrials.gov was performed from inception to June 4, 2020, for studies that had reported outcomes in patients who had ICD implanted after cardiac transplant. The outcomes studied were as follows: (a) SD and (b) appropriate and inappropriate ICD therapies. RESULTS: Seven studies (from 1983 through 2018) with a total of 338 cardiac transplant patients who received ICD met study inclusion criteria. The mean age was 48.37 ± 14.85 years, and 70.4% were men. The pooled incidence of SD was 16.3% (95% CI 6.2-29.0%; I2  = 66%). Appropriate and inappropriate ICD therapies were observed in 12.1% (95% CI 5.3-20.4; I2  = 0%) and 3.5% (95% CI 0.11-9.58%; I2  = 0%), respectively during the follow-up period (27.48 ± 24.27 months). The most common cause for SD was heart failure (15.6%), followed by electromechanical disassociation, malignant ventricular arrhythmias (4.7% each, respectively), and cardiac allograft vasculopathy (CAV) (3.1%). Furthermore, approximately 60% (10/17) of patients with appropriate ICD shocks had CAV. CONCLUSION: Despite, low incidence of arrhythmic mortality, there remains an increased burden of ventricular arrhythmias, as evident by a 12% appropriate ICD shock rates, suggesting ICD might be a practical decision in selected cardiac transplant patients deemed high risk of SD (i.e., patients with advanced CAV and left ventricular systolic dysfunction).

Bipolar radiofrequency ablation creates different lesion characteristics compared to simultaneous unipolar ablation.

INTRODUCTION: Both bipolar and simultaneous radiofrequency ablation (bRFA, simRFA) have been used to treat thick midmyocardial substrate as well as during circular, multipolar ablation between shorter distances. OBJECTIVES: We sought to evaluate the biophysical parameters of simRFA, sequential unipolar RFA (seqRFA), and bRFA. METHODS: Bovine myocardium was placed in a circulating saline bath. To simulate thick substrate conditions, two open irrigated ablation catheters were oriented across from each other, with myocardium in between. Thermocouples were placed in the center, ±2 mm, of the myocardium. Unipolar ablations were performed sequentially or simultaneously at 50 W for 60 seconds and compared to bRFA using the same settings. In addition, to simulate multipolar ablation, two open irrigated ablation catheters were oriented on the same side and perpendicular to myocardium at 1, 2, and 4 mm spacing. SimRFA were performed at 15 and 25 W for 60 seconds and compared to bRFA. RESULTS: For thicker tissue, simRFA produced similar lesion volume and depth compared to bRFA but with a lesion geometry similar to seqRFA. Unlike seqRFA and simRFA, bRFA had a necrotic core spanning the myocardium. Core depths, volumes, and temperatures were significantly greater for bRFA lesions compared to simRFA or seqRFA (Figure, P < .001). Similar results were consistent for bRFA and simRFA at shorter spacings. CONCLUSIONS: BRFA has greater core lesion temperatures, corresponding to a denser and larger necrotic core, than either simRFA or seqRFA. This may have implications for considering the optimal strategy for deep midmyocardial substrates or during multipolar ablation.

Electrophysiologic testing for diagnostic evaluation and risk stratification in patients with suspected cardiac sarcoidosis with preserved left and right ventricular systolic function.

INTRODUCTION: While cardiac sarcoidosis (CS) carries a risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD), risk stratification of patients with CS and preserved left ventricular/right ventricular (LV/RV) systolic function remains challenging. We sought to evaluate the role of electrophysiologic testing and programmed electrical stimulation of the ventricle (EPS) in patients with suspected CS with preserved ventricular function. METHODS: One hundred twenty consecutive patients with biopsy-proven extracardiac sarcoidosis and preserved LV/RV systolic function underwent EPS. All patients had either probable CS defined by an abnormal cardiac positron emission tomography or cardiac magnetic resonance imaging, or possible CS with normal advanced imaging but abnormal echocardiogram (ECG), SAECG, Holter, or clinical factors. Patients were followed for 4.5 ± 2.6 years for SCD and VAs. RESULTS: Seven of 120 patients (6%) had inducible ventricular tachycardia (VT) with EPS and received an implantable cardioverter defibrillator (ICD). Three patients (43%) with positive EPS later had ICD therapies for VAs. Kaplan-Meier analysis stratified by EPS demonstrated a significant difference in freedom from VAs and SCD (P = 0.009), though this finding was driven entirely by patients within the cohort with probable CS (P = 0.018, n = 69). One patient with possible CS and negative EPS had unrecognized progression of the disease and unexplained death with evidence of CS at autopsy. CONCLUSIONS: EPS is useful in the risk stratification of patients with probable CS with preserved LV and RV function. A positive EPS was associated with VAs. While a negative EPS appeared to confer low risk, close follow-up is needed as EPS cannot predict fatal VAs related to new cardiac involvement or disease progression.

Long term follow-up after ventricular tachycardia ablation in patients with congenital heart disease.

BACKGROUND: Ventricular tachycardia (VT) is frequently encountered in patients with repaired and unrepaired congenital heart disease (CHD), causing significant morbidity and sudden cardiac death. Data regarding underlying VT mechanisms and optimal ablation strategies in these patients remain limited. OBJECTIVE: To describe the electrophysiologic mechanisms, ablation strategies, and long-term outcomes in patients with CHD undergoing VT ablation. METHODS: Forty-eight patients (mean age 41.3 ± 13.3 years, 77.1% male) with CHD underwent a total of 57 VT ablation procedures at two centers from 2000 to 2017. Electrophysiologic and follow-up data were analyzed. RESULTS: Of the 77 different VTs induced at initial or repeat ablation, the underlying mechanism in 62 (81.0%) was due to scar-related re-entry; the remaining included four His-Purkinje system-related macrore-entry VTs and focal VTs mainly originating from the outflow tract region (8 of 11, 72.7%). VT-free survival after a single procedure was 72.9% (35 of 48) at a median follow-up of 53 months. VT-free survival after multiple procedures was 85.4% (41 of 48) at a median follow-up of 52 months. There were no major complications. Three patients died during the follow-up period from nonarrhythmic causes, including heart failure and cardiac surgery complication. CONCLUSION: While scar-related re-entry is the most common VT mechanism in patients with CHD, importantly, nonscar-related VT may also be present. In experienced tertiary care centers, ablation of both scar-related and nonscar-related VT in patients with CHD is safe, feasible, and effective over long-term follow-up.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias.

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/HRS Expert 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.

Use of half-normal saline irrigant with cooled radiofrequency ablation within the great cardiac vein to ablate premature ventricular contractions arising from the left ventricular summit.

A 62-year-old man was referred to our institution for high-density, symptomatic premature ventricular contractions (PVCs) with resultant decrease in left ventricular (LV) function having failed prior ablation attempts. Successful, durable ablation of the patient's mid-myocardial PVC arising from the LV summit region was achieved through the proximal great cardiac vein with ablation depth augmented by use of half-normal saline irrigant. Though standard ablation of ventricular arrhythmias using normal saline irrigation from the coronary venous system has been well-reported, this may be of limited value in addressing mid-myocardial sites of origin. This novel case describes the safe use of cooled radiofrequency ablation with use of half-normal saline irrigant from the distal coronary sinus as an option to address complex sites of PVC origin such as the LV summit.

Esophageal position, measured luminal temperatures, and risk of atrioesophageal fistula with atrial fibrillation ablation.

BACKGROUND: Despite improvement in catheter ablation for atrial fibrillation (AF), ability to recognize and prevent esophageal injury remains challenging. We hypothesized that esophageal course may impact esophageal heating, as measured through ablation, and thereby, risk of injury. METHODS: We evaluated all patients undergoing first-time AF ablation with preprocedural computed tomography (CT) imaging from 2014 to 2016 at our institution, focusing on esophageal position at the left atrial (LA)/pulmonary vein junction. Esophageal luminal temperatures (ELTs) were analyzed by esophageal course. In exploratory work by investigation of published reports of atrioesophageal fistula (AEF), we evaluated for a relationship between esophageal course and risk of AEF. RESULTS: Of 68 patients, 48.5% had midline, 36.8% leftward, and 14.7% rightward esophageal positions. Of 20 patients (29% of cohort) with esophageal confinement-defined as a midline or leftward position relative to the LA, vertebrae, and aorta, with luminal distortion-14 had leftward position. No significant differences in patient or procedure characteristics were noted between confinement and nonconfinement cohorts. The average peak ELT was significantly higher in those with confinement (36.9°C vs 36.2°C, P < 0.05) and confinement with a left-sided esophagus (37.1°C vs 36.2°C, P < 0.05). There was a significant correlation between esophageal confinement and risk of AEF (odds ratio [OR]: 2.7, 95% confidence interval [CI]: 1.2-6.2, P < 0.01). CONCLUSION: Approximately one-third of patients undergoing AF ablation display leftward esophageal course along the ablation zone on preprocedure CT imaging, with a significant portion exhibiting esophageal confinement. In those with confinement, higher peak ELTs are noted with ablation. Esophageal confinement may be a risk factor for development of AEF.