Correlation of ECG and cardiac MRI for assessment of ventricular hypertrophy and dilatation in adults with repaired tetralogy of Fallot.

Background: Surgically repaired Tetralogy of Fallot (rTOF) is associated with progressive right ventricular hypertrophy (RVH) and dilation (RVD). Accurate estimation of RVH/RVD is vital for the ongoing management of this patient population. The utility of the ECG in evaluating patients with rTOF with pre-existing right bundle branch block (RBBB) has not been studied.

Long-term outcomes of catheter ablation compared with medical therapy in atrial fibrillation.

Background: The long-term effects of catheter ablation (CA) compared with medical therapy on cardiovascular outcomes for atrial fibrillation (AF) remain undetermined.

Objective: Using a population-based cohort, we sought to determine what the association between CA and medical therapy was on these outcomes.

Methods: By use of Alberta administrative data, patients with AF as the primary diagnosis during hospitalization, emergency department visit, or physician visit were included between October 1, 2008, and March 31, 2018.

Catheter Ablation or Antiarrhythmic Drugs for Ventricular Tachycardia.

Background: Patients with ventricular tachycardia and ischemic cardiomyopathy are at high risk for adverse outcomes. Catheter ablation is commonly used when antiarrhythmic drugs do not suppress ventricular tachycardia. Whether catheter ablation is more effective than antiarrhythmic drugs as a first-line therapy in patients with ventricular tachycardia is uncertain.

Long-Term Differences in Autonomic Alterations After Cryoballoon vs Radiofrequency Atrial Fibrillation Ablation.

Background: The long-term natural history of autonomic alterations following catheter ablation of drug-refractory paroxysmal atrial fibrillation is poorly defined.

Objectives: The authors sought to define the long-term impact of thermal catheter ablation on the cardiac autonomic system.

Methods: The study included 346 patients with drug-refractory paroxysmal atrial fibrillation undergoing pulmonary vein isolation using thermal ablation energy (radiofrequency or cryoballoon ablation).

Association Between Oral Anticoagulant Adherence and Serious Clinical Outcomes in Patients With Atrial Fibrillation: A Long-Term Retrospective Cohort Study.

Background: Patients with atrial fibrillation are frequently nonadherent to oral anticoagulants (OACs) prescribed for stroke and systemic embolism (SSE) prevention. We quantified the relationship between OAC adherence and atrial fibrillation clinical outcomes using methods not previously applied to this problem.

Methods And Results: Retrospective observational cohort study of incident cases of atrial fibrillation from population-based administrative data over 23 years.

The Diagnostic Utility of Holter Monitoring in Catecholaminergic Polymorphic Ventricular Tachycardia.

Background: Holter monitoring may raise suspicion of an underlying catecholaminergic polymorphic ventricular tachycardia (CPVT) diagnosis. Although not a primary investigation for CPVT, Holter monitoring is ubiquitously used as a diagnostic tool in the heart rhythm clinic.

Objectives: The objective of this study was to explore Holter monitoring in CPVT diagnosis.

Development and Application of an Attribute-Based Taxonomy on the Benefits of Oral Anticoagulant Switching in Atrial Fibrillation: A Delphi Study.

Introduction: Patients with atrial fibrillation (AF) often switch between oral anticoagulants (OACs). It can be hard to know why a patient has switched outside of a clinical setting. Medication attribute comparisons can suggest benefits.

Analysis of left ventricle regional myocardial motion for cardiac radioablation: Left ventricular motion analysis.

Purpose: Left ventricle (LV) regional myocardial displacement due to cardiac motion was assessed using cardiovascular magnetic resonance (CMR) cine images to establish region-specific margins for cardiac radioablation treatments.

Methods: CMR breath-hold cine images and LV myocardial tissue contour points were analyzed for 200 subjects, including controls (n = 50) and heart failure (HF) patients with preserved ejection fraction (HFpEF, n = 50), mid-range ejection fraction (HFmrEF, n = 50), and reduced ejection fraction (HFrEF, n = 50). Contour points were divided into segments according to the 17-segment model.

Left ventricle segment-specific motion assessment for cardiac-gated radiosurgery.

Cardiac radiosurgery is a non-invasive treatment modality for ventricular tachycardia, where a linear accelerator is used to irradiate the arrhythmogenic region within the heart. In this work, cardiac magnetic resonance (CMR) cine images were used to quantify left ventricle (LV) segment-specific motion during the cardiac cycle and to assess potential advantages of cardiac-gated radiosurgery.CMR breath-hold cine images and LV contour points were analyzed for 50 controls and 50 heart failure patients with reduced ejection fraction (HFrEF, EF < 40%).

Adherence to direct or vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: a long-term observational study.

Our objectives were to measure long-term adherence to oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and to identify patient factors associated with adherence. Using linked, population-based administrative data from British Columbia, Canada, an incident cohort of adults prescribed OACs for AF was identified. We calculated the proportion of days covered (PDC) as a time-dependent covariate for each 90-day window from OAC initiation until the end of follow-up.

Atrial fibrillation progression after cryoablation vs. radiofrequency ablation: the CIRCA-DOSE trial.

Background And Aims: Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression.

Assessment and management of asymptomatic atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia encountered in practice. It is currently estimated that AF affects approximately 2% of the general population; however, the true prevalence of AF is likely to be at least 3%-4% when asymptomatic AF is considered. For clinically apparent AF, the investigations and management are relatively well established.

Trigger and Substrate Mapping and Ablation for Ventricular Fibrillation in the Structurally Normal Heart.

Sudden cardiac death (SCD) represents approximately 50% of all cardiovascular mortality in the United States. The majority of SCD occurs in individuals with structural heart disease; however, around 5% of individuals have no identifiable cause on autopsy. This proportion is even higher in those <40 years old, where SCD is particularly devastating.

PV Isolation Using a Spherical Array PFA Catheter: Preclinical Assessment and Comparison to Radiofrequency Ablation.

Background: A multielectrode spherical array catheter capable of single-shot mapping and ablation has been introduced.

Objectives: This study sought to compare the efficacy and safety of circumferential, linear, and focal ablation using either microsecond pulsed field (PF) and radiofrequency (RF) ablation in preclinical model.

Methods: Under general anesthesia, a 122 gold-plated multielectrode array was introduced into the left atrium.

Rhythms from Two Competing Periodic Sources Embedded in an Excitable Medium.

In an excitable medium, a stimulus generates a wave that propagates in space until it reaches the boundary or collides with another wave and annihilates. We study the dynamics generated by two periodic sources with different frequencies in excitable cardiac tissue culture using optogenetic techniques. The observed rhythms, which can be modeled using cellular automata and studied analytically, show unexpected regularities related to classic results in number theory.

Patient experiences of implantable cardiac monitoring in hypertrophic cardiomyopathy: an exploratory study.

Aims: Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease. Insertable cardiac monitors (ICMs) are increasingly used in this population to provide closer monitoring, with the potential for notification systems. However, little is known regarding the psychological impact this information may have on patients.

Correlation of unipolar electrogram modification with ablation index during pulmonary vein isolation: A pilot study.

Background: Pulmonary vein isolation (PVI) using radiofrequency catheter ablation is a widely accepted therapy for drug-refractory atrial fibrillation patients. Elimination of the negative component of the local unipolar electrogram (UEGM) during PVI is a marker of transmural lesion formation. The ablation index (AI) can predict the quality of ablation lesion.