The power of three: Atrial rate limit power-on-reset - A non-electromagnetic cause of pacemaker-induced extracardiac stimulation.

Background: Power-on reset (PoR) is most commonly due to electromagnetic interference. Full PoR results in a switch to an inhibited mode (VVI) pacing and resets pacing outputs to maximal unipolar settings, leading to extracardiac stimulation.

Methods: We present a case of PoR occurrence in the absence of electromagnetic interference, resulting in pectoral stimulation triggered by violation of the atrial rate limit.

Incidence and Predictors of New-Onset Atrial Fibrillation After Transcatheter Edge-to-Edge Repair of the Mitral Valve (from the Nationwide Readmissions Database).

Patients who underwent transcatheter edge-to-edge repair (TEER) for mitral regurgitation with atrial fibrillation (AF) at baseline have higher mortality than those without AF. Data on new-onset AF (NOAF) after TEER are limited. Using the 2016 to 2018 Nationwide Readmissions Database, we identified a cohort of patients who underwent TEER and classified them into 3 groups based on AF presence during the study period.

The missing link: Unlocking the power of cardiac rhythm monitoring device based QT interval detection.

Background: The QT interval is of high clinical value as QT prolongation can lead to Torsades de Pointes (TdP) and sudden cardiac death. Insertable cardiac monitors (ICMs) have the capability of detecting both absolute and relative changes in QT interval. In order to determine feasibility for long-term ICM based QT detection, we developed and validated an algorithm for continuous long-term QT monitoring in patients with ICM.

Cardiac Resynchronization and Circulating Markers of Sarcoplasmic Reticulum Calcium Handling and Sudden Death Risk.

Cardiac resynchronization therapy (CRT) can improve heart function and decrease arrhythmic events. We tested whether CRT altered circulating markers of calcium handling and sudden death risk. Circulating cardiac sodium channel messenger RNA (mRNA) splicing variants indicate arrhythmic risk, and a reduction in sarco/endoplasmic reticulum calcium adenosine triphosphatase 2a (SERCA2a) is thought to diminish contractility in heart failure.

Hemodynamic effects of left atrial appendage occlusion.

Background: Percutaneous left atrial appendage occlusion (LAAO) devices have emerged as alternatives to anticoagulation for embolic stroke prevention in patients with non-valvular atrial fibrillation (NVAF). The left atrial appendage is known to produce vasoactive neuroendocrine hormones involved in cardiovascular homeostasis. The hemodynamic impact of LAA occlusion on cardiac function remains poorly characterized.

Impact of Racial and Gender Variations in Patients With Out-of-hospital Cardiac Arrest: A Nation-Wide Study.

The overall incidence of Out-of-hospital Cardiac Arrest (OHCA) is decreasing worldwide due to emergency responses, but there are gender and racial differences in the incidence of OHCA, which remain under investigation. Our aim was to identify the incidence, gender, and racial disparities in patients admitted with OHCA. The National Inpatient Sample Database is one of the largest all-payer inpatient database.

Thirty-day readmissions after atrial fibrillation catheter ablation in patients with heart failure.

Background: Randomized clinical trial data have demonstrated catheter ablation (CA) as a viable treatment modality for atrial fibrillation (AF). Patients with heart failure (HF) undergoing AF CA appear to derive improvements in quality of life and mortality compared to those treated with medical therapy (MT). Contemporary national data on 30-day readmissions after CA compared to MT among patients with HF are lacking.

Cardiac implantable electronic device placement following alcohol septal ablation for hypertrophic cardiomyopathy in the United States.

Background: Cardiac implantable electronic devices (CIED) are sometimes required after alcohol septal ablation (ASA) for hypertrophic cardiomyopathy (HCM). The primary objectives of this study were to characterize the incidence, timing, and predictors of CIED placement after ASA for HCM.

Methods: Patients were identified from the 2010-2015 Nationwide Readmissions Databases.

Aortic Valve Calcification as a Predictor of Post-Transcatheter Aortic Valve Replacement Pacemaker Dependence.

Background: Atrioventricular block requiring permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve replacement (TAVR). The mechanism of atrioventricular (AV) block during TAVR is not fully understood, but it may be due to the mechanical stress of TAVR deployment, resulting in possible injury to the nearby compact AV node. Aortic valve calcification (AVC) may worsen this condition and has been associated with an increased risk for post-TAVR PPM implantation.

Incidence and Risk Factors for Atrial Fibrillation Recurrence after Ablation of Nodal and Atrioventricular Reentrant Tachycardia: A Meta-analysis.

Introduction Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) are frequently associated with atrial fibrillation (AF). Targeting the slow or accessory pathways has been advocated as therapy for coexisting AF. But in practice, AF has frequently recurred after ablation, possibly because of various risk factors.

Sudden death in a patient with long QT syndrome presenting with an epileptic phenotype.

Patients with epilepsy suffer from a higher mortality rate than the general population, a portion of which is not due to epilepsy itself or comorbid conditions. Sudden unexpected death in epilepsy (SUDEP) is a common but poorly understood cause of death in patients with intractable epilepsy and often afflicts younger patients. The pathophysiology of SUDEP is poorly defined but does not appear to be related to prolonged seizure activity or resultant injury.

Atrial Fibrillation in Hypertrophic Cardiomyopathy: Evidence-based Review About Mechanism, Complications and Management.

Hypertrophic cardiomyopathy (HCM) is 1 of the most frequent genetic cardiovascular diseases affecting 1 out of every 500 individuals in general population. Atrial Fibrillation incidences were 3.8% per 100 patients per year and overall prevalence among HCM patients are 27.

Maternal monitoring and safety considerations during antiarrhythmic treatment for fetal supraventricular tachycardia.

Fetal tachycardia is a rare complication during pregnancy. After exclusion of maternal and fetal conditions that can result in a secondary fetal tachycardia, supraventricular tachycardia is the most common cause of a primary sustained fetal tachyarrhythmia. In cases of sustained fetal supraventricular tachycardia, maternal administration of digoxin, flecainide, sotalol, and more rarely amiodarone, is considered.

Brugada Syndrome: Death Reveals its Perpetrator.

Rapid diagnosis of Brugada syndrome is critical to therapy, which is aimed at reversing provoking factors to suppress/terminate malignant arrhythmias. This case highlights the diagnosis and peri-operative management of patients with Brugada syndrome at high risk for sudden cardiac death. ().

Atrial Infarction-Induced Spontaneous Focal Discharges and Atrial Fibrillation in Sheep: Role of Dantrolene-Sensitive Aberrant Ryanodine Receptor Calcium Release.

Background: The mechanisms underlying spontaneous atrial fibrillation (AF) associated with atrial ischemia/infarction are incompletely elucidated. Here, we investigate the mechanisms underlying spontaneous AF in an ovine model of left atrial myocardial infarction (LAMI).

Methods And Results: LAMI was created by ligating the atrial branch of the left anterior descending coronary artery.

A Simple Score That Predicts Paroxysmal Atrial Fibrillation on Outpatient Cardiac Monitoring after Embolic Stroke of Unknown Source.

Background: Occult paroxysmal atrial fibrillation (AF) is detected in 16%-30% of patients with embolic stroke of unknown source (ESUS). The identification of AF predictors on outpatient cardiac monitoring can help guide clinicians decide on a duration or method of cardiac monitoring after ESUS.

Methods: We included all patients with ESUS who underwent an inpatient diagnostic evaluation and outpatient cardiac monitoring between January 1, 2013, and December 31, 2016.

Left Atrial Appendage Morphology and Embolic Stroke of Undetermined Source: A Cross-Sectional Multicenter Pilot Study.

Background: The left atrial appendage (LAA) is the main source of thrombus in atrial fibrillation, and there is an association between non-chicken wing (NCW) LAA morphology and stroke. We hypothesized that the prevalence of NCW LAA morphology would be higher among patients with cardioembolic (CE) stroke and embolic stroke of undetermined source (ESUS) than among those with noncardioembolic stroke (NCS).

Methods: This multicenter retrospective pilot study included consecutive patients with ischemic stroke from 3 comprehensive stroke centers who previously underwent a qualifying chest computed tomography (CT) to assess LAA morphology.

Predictors of right ventricular pacing and pacemaker dependence in transcatheter aortic valve replacement patients.

Purpose: Transcatheter aortic valve replacement (TAVR) is an increasingly prevalent therapy in patients with severe symptomatic aortic stenosis. Conduction disturbances requiring permanent pacemaker (PPM) implantation are a known complication of TAVR. This study investigated the progression of cardiac conduction disease in the post-TAVR pacemaker population and identified predictors of post-TAVR right ventricular (RV) pacing dependence.

Leadless Cardiac Pacemakers: The Next Evolution in Pacemaker Technology.

Implantable pacemakers stand as a mainstay in our therapeutic arsenal, affording those suffering from advanced cardiac conduction system disease both an improved quality of life and reduced mortality. Annually, over 225,000 new pacemakers are implanted in the United States for bradyarrhythmias and heart block. The first implantable transvenous pacemakers appeared in 1965; they were bulky devices, hobbled by a short battery life, and a single pacing mode.

Left Atrial Enlargement and Anticoagulation Status in Patients with Acute Ischemic Stroke and Atrial Fibrillation.

Background: Despite anticoagulation therapy, ischemic stroke risk in atrial fibrillation (AF) remains substantial. We hypothesize that left atrial enlargement (LAE) is more prevalent in AF patients admitted with ischemic stroke who are therapeutic, as opposed to nontherapeutic, on anticoagulation.

Methods: We included consecutive patients with AF admitted with ischemic stroke between April 1, 2015, and December 31, 2016.

PR Interval Prolongation and Cryptogenic Stroke: A Multicenter Retrospective Study.

Background: Atrial dysfunction or "cardiopathy" has been recently proposed as a mechanism in cryptogenic stroke. A prolonged PR interval may reflect impaired atrial conduction and thus may be a biomarker of atrial cardiopathy. We aim to compare the prevalence of PR interval prolongation in patients with cryptogenic stroke (CS) when compared with known non-cryptogenic non-cardioembolic stroke (NCNCS) subtypes.

PVCs, PVC-Induced Cardiomyopathy, and the Role of Catheter Ablation.

Premature ventricular contractions (PVCs) are common arrhythmias noticed in the clinical setting because of premature depolarization of the ventricular myocytes. Although often thought to be reflective of underlying disease rather than intrinsically harmful, PVCs have recently been linked with worse outcomes in patients without significant cardiac disease. Long-term exposure to a high PVC burden can lead to the development of PVC-induced cardiomyopathy.

Minimally Invasive Closure of the Left Atrial Appendage: A Non-Pharmacologic Approach to Prevention of Stroke in Patients with Atrial Fibrillation.

Atrial Fibrillation's (AF) role in the pathogenesis of thromboembolic stroke has been well established, with estimates from trials of approximately 15-20% of all strokes in the U.S. Research shows more than 90% of atrial thrombi originate from the left atrial appendage (LAA).