Publications by authors named "Kenneth A Ellenbogen"

Background: The mechanisms underlying postoperative atrial fibrillation (POAF) remain unclear.

Objectives: The aim of this study was to test the hypothesis that targeted chemical ganglionated plexi (GP) modulation of all major left atrial-pulmonary vein GP using novel nanoformulated calcium chloride (nCaCl) can reverse postoperative neuroelectrical remodeling by suppressing vagosympathetic nerve activity and the localized inflammatory process, both critical substrates of POAF.

Methods: In a novel canine model of POAF with serial thoracopericardiotomies, sympathetic nerve activity (SNA), vagal nerve activity (VNA) and GP nerve activity (GPNA) were recorded; spontaneous and in vivo AF vulnerability were assessed; and atrial and circulating inflammatory markers and norepinephrine (NE) were measured to determine the neuroelectrical remodeling that promotes POAF and its subsequent modulation with nCaCl GP treatment (n = 6) vs saline sham controls (n = 6).

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Background: Understanding the conduction axis location aids in avoiding iatrogenic damage and guiding targeted heart rhythm therapy.

Objective: Cardiac structures visible with clinical imaging have been demonstrated to correlate with variability in the conduction system course. We aimed to standardize and assess the reproducibility of predicting the location of the atrioventricular conduction axis by cardiac computed tomography.

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Conduction disturbances (CDs) are common after transcatheter aortic valve replacement. Continuous improvements in preprocedural planification, implant techniques, and device design have markedly reduced periprocedural complications. However, CDs rate remains in the double-digit range.

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Left bundle branch block (LBBB) is frequently associated with structural heart disease, and predicts higher rates of morbidity and mortality. In patients with cardiomyopathy (ejection fraction <35%) and LBBB, current guidelines recommend cardiac resynchronisation therapy (CRT) after 3 months of medical therapy. However, studies have suggested that medical therapy alone would be less effective, and the majority of patients would still need CRT at the end of 3 months.

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Article Synopsis
  • Premature ventricular contractions (PVCs) are common in individuals with left ventricular (LV) systolic dysfunction, yet their prevalence in the general population is not well understood.
  • A multicenter study evaluated the prevalence of frequent (PVCs >5%) and high burden (PVCs >10%) PVCs among patients monitored with ambulatory Holter monitors, analyzing demographics and left ventricle ejection fraction (LVEF).
  • Results showed that PVCs >5% and >10% were present in 4% and 5% of participants, respectively, with higher prevalence in older males, while females had a lower occurrence of PVCs despite similar rates when LVEF <50%.
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  • Management of persistent atrial fibrillation (AF) remains challenging despite improvements in catheter-based treatments and repeat ablation procedures.
  • Atrioventricular node ablation (AVNA) has regained importance as a treatment option due to advancements in cardiac pacing technology, which address pacing-induced cardiomyopathy concerns.
  • The review will explore the role of permanent pacemaker implantation and AVNA in AF management, highlighting its effects on haemodynamics, benefits of 'pace-and-ablate therapy', and identifying patient groups that might benefit from this approach earlier.
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  • * Recent advancements, particularly using hierarchical phase-contrast tomography (HiP-CT), allow for a detailed, three-dimensional view of the conduction axis in heart specimens.
  • * By integrating these findings with 3D scans of living patients, researchers can now better predict the conduction axis's location, improving clinical insights and treatments.
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Background: Cardiac resynchronization therapy (CRT) is a guideline-recommended therapy in patients with heart failure with mildly reduced ejection fraction (HFmrEF, 36%-50%) and left bundle branch block or indication for ventricular pacing. Conduction system pacing (CSP) using left bundle branch area pacing or His bundle pacing has been shown to be a safe and physiologic alternative to biventricular pacing (BVP).

Objective: The aim of this study was to compare the clinical outcomes between BVP and CSP for patients with HFmrEF undergoing CRT.

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  • Conduction system pacing (CSP) is being explored as a better option than traditional right ventricular (RV) pacing, but previous studies have been limited.
  • This large study analyzed Medicare data to compare outcomes between patients using CSP and those with dual-chamber (DC) RV pacing, separating CSP patients into two groups: left bundle branch area pacing (LBBAP) and His bundle pacing (HBP).
  • Results showed that CSP patients had significantly lower rates of heart failure hospitalizations and all-cause mortality compared to DC RV patients, with LBBAP patients experiencing fewer complications than HBP patients.
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Background: The current standard of practice for cremating patients with cardiac implantable electronic devices (CIEDs) is surgical explantation before cremation to mitigate the risk of device explosion. This surgery may conflict with patient or family beliefs, whereas cremation of CIEDs may create occupational hazards.

Objective: This study sought to establish an ex vivo model for screening CIED behavior during cremation.

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Background: Despite their improved safety, by and large, cardiac electrophysiology procedures including catheter ablation (CA), are presently performed in hospital outpatient departments.

Objective: This large multicenter study investigated the safety and outcomes associated with various cardiac electrophysiology procedures performed at 6 ambulatory surgery centers (ASCs), primarily during the coronavirus disease 2019 pandemic under the Center for Medicare and Medicaid Services Hospitals Without Walls program.

Methods: We retrospectively analyzed the outcomes from consecutive electrophysiology procedures performed in ASCs with same-day discharge, including transesophageal echocardiography, cardioversion, cardiac implantable electronic device (CIED) implantation, electrophysiology studies, and CA for atrial fibrillation (AF), atrial flutter (AFL)/supraventricular tachycardia, ventricular premature complexes (VPCs), and atrioventricular node.

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  • The study aimed to evaluate the day-to-day variability in the frequency of premature atrial complexes (PACs) and premature ventricular complexes (PVCs) using 14-day ECG recordings from 8245 patients.
  • Results showed that significant daily variability exists; for PACs, 25% of patients had daily frequencies that differed by over 50% from their 14-day average after just 3 days, while for PVCs, it took 7 days to see similar variation.
  • The findings indicate that when patients report very high frequencies (≥10,000), single-day ECG results are highly specific and do not require longer recordings for confirmation.
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  • Multiple states have implemented CPR training for high school students and staff to reduce sudden cardiac death (SCD), but the quality and execution of these mandates differ significantly across the country.
  • A scoring system was created to objectively assess CPR training mandates in all 50 states and the District of Columbia, revealing a wide range in scores that indicate the robustness of these mandates.
  • The study's findings suggest that although there is variability in state mandates, no strong link was found between CPR training requirements and reduced SCD rates, underscoring the need for more consistent and effective policies.
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Background: The significance of autonomic dysfunction in premature ventricular contraction-induced cardiomyopathy (PVC-CM) remain unknown.

Objectives: Utilizing a novel "dual stressor" provocative challenge combining exercise with premature ventricular contraction (PVCs), the authors characterized the functional and molecular mechanisms of cardiac autonomic (cardiac autonomic nervous system) remodeling in a PVC-CM animal model.

Methods: In 15 canines (8 experimental, 7 sham), we implanted pacemakers and neurotelemetry devices and subjected animals to 12 weeks of bigeminal PVCs to induce PVC-CM.

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  • The study investigates the impact of periprocedural myocardial injury (PMI) on clinical outcomes in patients undergoing Left Bundle Branch Area Pacing (LBBAP), finding that PMI is common and might worsen outcomes.
  • Among 130 patients, 55% experienced PMI, with those showing significant increases in troponin levels (above four times the normal threshold) facing higher hospitalization rates, particularly for acute coronary syndrome.
  • Factors like multiple lead reposition attempts and specific lead types were linked to a greater risk of experiencing PMI during the procedure.
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Background: Autonomic denervation is an ancillary phenomenon during thermal ablation of atrial fibrillation (AF), that may have synergistic effects on symptomatic improvement and long-term freedom from AF. Pulsed field ablation (PFA), a nonthermal ablation modality, was noninferior to thermal ablation in treating AF; however, PFA's relative myocardial selectivity may minimize autonomic effects.

Objectives: This study sought to compare heart rate (HR) and heart rate variability (HRV) metrics as markers of autonomic function after ablation using PFA vs thermal ablation.

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Arrhythmias frequently accompany heart failure and left ventricular dysfunction. Tachycardias, atrial fibrillation, and premature ventricular contractions can induce a reversible form of dilated cardiomyopathy (CM) known as arrhythmia-induced CM (AiCM). The intriguing question is why certain individuals are more susceptible to AiCM, despite similar arrhythmia burdens.

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