Masry, Hicham El

Despite advances in ablative therapies, outcomes remain less favorable for persistent atrial fibrillation often due to presence of non-pulmonary vein triggers and abnormal atrial substrates. This review highlights advances in ablation technologies and notable scientific literature on clinical outcomes associated with pursuing adjunctive ablation targets and substrate modification during persistent atrial fibrillation ablation, while also highlighting notable future directions.

Cardiac sarcoidosis (CS) is characterized by various arrhythmic manifestations ranging from catastrophic sudden cardiac death secondary to ventricular arrhythmia, severe conduction disease, sinus node dysfunction, and atrial fibrillation. The management of CS is complex and includes not only addressing the arrhythmia but also controlling the myocardial inflammation resultant from the autoimmune reaction. Arrhythmic manifestations of CS carry significant prognostic implications and invariably affect long-term survival in these patients. In this review, we focus on management of arrhythmic manifestation of cardiac sarcoidosis as well as risk stratification for sudden cardiac death in these patients.

AbstractIntroductionVentricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years.MethodsWe performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006 to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed.ResultsA total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5–297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545 (IQR 152–1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES (hazards ratio [HR]: 1.92, 95% CI: 1.39–2.64, p < .001).ConclusionFollowing LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre‐implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Mechanical valves in both aortic and mitral positions pose a challenge for left ventricular (LV) access during ventricular tachycardia (VT) ablation using the antegrade transseptal or the retrograde transaortic approach. A 57 year-old male with ischemic cardiomyopathy, mechanical aortic and mitral valves, and recurrent VT underwent a combined endocardial and epicardial ablation via direct ventricular puncture via mini-thoracotomy. Successful mapping with endocardial and epicardial ablation was performed, with no recurrent VT on follow up. We showcase the feasibility of VT ablation using an open transapical approach for patients with mechanical aortic and mitral valves.

Although substantial progress has been made to prevent sudden cardiac death in repaired tetralogy of Fallot patients, ventricular arrhythmia and sudden death continue to be major causes of morbidity and mortality in these patients. Greater survival in contemporary cohorts has been attributed to enhanced surgical techniques, more effective management of heart failure, and increased efforts in risk stratification and management of ventricular arrhythmias. More recently, our understanding of predictive risk factors has evolved into personalized risk prediction tools that rely on comprehensive demographic, imaging, functional, and electrophysiological data. However, the universal applicability of these different scoring systems is limited due to differences between study cohorts, types of anatomic repair, imaging modalities, and disease complexity. Noninvasive risk stratification is critical to identify those who may derive benefit from catheter ablation or cardioverter defibrillator implantation for primary prevention. Ultimately, assessment and risk stratification by a multidisciplinary team is crucial to analyze the various complex factors for every individual patient and discuss further options with patients and their families.

AbstractBackgroundReal‐world clinical data on the adverse events related to the use of cryoballoon catheter for pulmonary vein isolation remains limited.ObjectiveTo report and describe the adverse events related to the use of Artic Front cryoballoon catheters (Arctic Front, Arctic Front Advance, and Arctic Front Advance Pro) reported in the Food and Drug Administration's (FDA) Manufacturers and User Defined Experience (MAUDE) database.MethodsWe reviewed all the adverse events reported to the FDA MAUDE database over a 10.7‐year study period from January 01, 2011 to September 31, 2021. All events were independently reviewed by two physicians.ResultsDuring the study period, a total of 320 procedural‐related adverse events reported in the MAUDE database were identified. The most common adverse event was transient or persistent phrenic nerve palsy (PNP), accounting for 48% of all events. This was followed by cardiac perforation (15%), pulmonary vein stenosis (8%), transient ischemic attack or stroke (6%), vascular injury (4%), transient or persistent ST‐elevation myocardial infarction (3%), hemoptysis (2%), pericarditis (2%), and esophageal ulcer or fistula (1%). There were six reported intra‐procedural death events as a result of cardiac perforation.ConclusionThe two most common procedural adverse events associated with cryoballoon ablation were PNP and cardiac perforation. All cases of procedural mortality were due to cardiac perforation.

Atrial fibrillation is a diverse clinical entity, with persistent atrial fibrillation (PeAF) being particularly challenging to manage. Through this paper, we discuss notable developments in our understanding of ablative strategies for managing PeAF, with a special focus on posterior wall isolation (PWI).

Introduction: Studies on leadless pacemakers (LP) are very limited and they often fail to reflect real population outcomes. Hypothesis: We sought to evaluate the effect of leadless pacemaker implantation on the echocardiographic parameters including ventricular function and valvular competence. Methods: A retrospective review including 162 patients (81 Micra Leadless pacemaker implant and 81 dual-chamber transvenous pacemakers) from 3 centers were included. Follow-up clinical, echocardiographic, and pacing characteristics were obtained over a median of 14+/-2 months. Results: baseline demographics and clinical characteristics were comparable between the 2 groups including age (78.6+/-9.9, Range 35-95) and gender (49 males, 69.5%). Compared to conventional pacemakers, LP patients had worsening tricuspid regurgitation noted on follow-up echo in 59.3% of patients compared to baseline(P<0.001). This difference was independent of the RV pacing percentage and device location. In addition, LP implantation resulted in a reduction of RV function (P=0.003) and left ventricular ejection fraction (P=0.03). The RV Pacing burden in LP patient patients was not associated with a change in LVEF during the follow-up period (95% CI -0.24, 0.20, p = 0.846). Conclusions: LP therapy is associated with worsening tricuspid valve regurgitation and biventricular dysfunction over a mean 1 year of follow-up. Additional prospective randomized studies are warranted to further evaluate these findings.

Background: Recognition of the causes of early mortality after ventricular tachycardia (VT) ablation in patients with reduced left ventricular ejection fraction is an essential step toward improving post-procedural outcomes. Objective: This study sought to determine the causes of early mortality (≤30-days) after VT ablation in patients with reduced left ventricular ejection fraction and to understand further the circumstances surrounding death after the procedure. Methods: We performed a retrospective analysis of all patients undergoing VT ablation in patients with reduced left ventricular ejection fraction from January 1, 2013, to November 10, 2021, at the Mayo Clinic (Rochester, Phoenix, and Jacksonville). Causes of death were identified through a detailed chart review of the electronic health record within the Mayo Clinic system and outside records. Results: A total of 503 patients (mean age 63 ± 13 years, 11.2% female) with EF <50% were included in the study. The 30-day all-cause mortality rate was 5% (n=25), and the mortality rate due to a procedural complication was 0.4%. Among all 30-day deaths, recurrent VT was the most common primary cause of death (44%). This was followed by decompensated heart failure (28%), procedure-related death (8%), cerebrovascular accident (CVA) (4%), and infection (4%). Most patients (91%) who died from VT had the VT recurrence within three days of the ablation. 76% of patients with early mortality had delayed referral for VT ablation, and 72% opted for comfort care before death. Conclusions: The overall early mortality (≤30-days) rate after catheter ablation of VT in patients with reduced left ventricular ejection fraction was 5%, but the death rate directly due to a procedural complication was only 0.4%. The most common cause of death was recurrent VT, followed by heart failure. Further research into ablation strategies is vital to improving the safety, efficacy, and durability of VT ablation.

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Immune checkpoint inhibitor (ICI) myocarditis is a life-threatening condition characterized by lymphocytic myocardial infiltration[1]. Complete heart block (CHB) occurs in 15% of cases and is often fatal[2-4]. The nature and optimal management of this often-malignant condition is poorly understood[5]. Purpose This case series assesses prognostic factors associated with survival at 90 days among people with ICI myocarditis and CHB. Methods The electronic patient record system was used to identify patients admitted with ICI myocarditis. A two-physician review was used to assess the presence of ICI-associated CHB. Wilcoxon rank sum and Spearman’s rank correlation were used for categorical and quantitative variables respectively. Data was analysed using STATA/IC 16.1. The primary outcome was person-day survival 90 days after presenting symptom onset. Results Six patients were included in the final analysis. Mean survival was 47 person days. All had metastatic disease and presented 15 to 32 days after the first ICI infusion. All had muscle weakness. Other common self-symptoms were shortness of breath (4), blurred vision (4), double vision (3), collapse (3), and leg swelling (1). Proximal myopathy (2), fatigable myopathy (1), ptosis (3), and peripheral oedema (1) were present on examination. Raised troponin T and white blood cell count (WBC) were associated with 90-day survival (see Table 1). Nt-pro BNP, AST, and CK levels were raised in all patients. Two patients were tested for anti-striated muscle antibody titres, and both were strongly positive. Increase in QRS duration compared to baseline ECG was associated with lower survival at 90 days. Only one patient had CHB on admission. Steroid dose, IVIG, and plasmapheresis weren’t associated with survival. One patient declined device therapy. One declined permanent pacemaker (PPM) after insertion of transvenous pacemaker (TVP). Both died within 2 weeks. Three people underwent insertion of a transvenous pacemaker (TVP) followed by PPM insertion (table 2). All three eventually died within 100 days. One person received isoproterenol and immunosuppression as a bridge to PPM and survived. One patient was managed initially with TVP but subsequently declined PPM insertion. TVP removal resulted in CHB recurrence, and they died shortly after discharge. One person declined device therapy and died while receiving comfort care. Lead malfunction was frequent. One patient experienced bradycardia arrest with failure of a TVP lead to capture, while another experienced lead dislodgement. Conclusion CHB secondary to ICI is often fatal. It should be considered in patients presenting with symptoms of myositis, raised troponin and increased QRS duration. Despite a small sample size, this study identifies several prognostic factors which can guide both patients and physicians with decision-making. Larger studies are needed to better understand the role of device therapy in this population.