Publications by authors named "Joseph B Morton"
Background: Early recurrence of atrial tachyarrhythmia (ERAT) is common after catheter ablation of atrial fibrillation (AF). The specific clinical and arrhythmia characteristics of ERAT influencing late recurrence risk in persistent AF are unclear. In addition, the impact of different ablation strategies on the incidence and prognostic significance of ERAT remains unknown.
View Article and Find Full Text PDFArticle Synopsis
- The left ventricular summit (LVS) is a key area where epicardial arrhythmias frequently occur, making it a significant focus for medical professionals.
- Ablating arrhythmias at the LVS is particularly challenging due to its complicated anatomical structure and proximity to other vital heart areas.
- This review provides an in-depth analysis of the LVS anatomy and offers a thorough overview of the techniques used for mapping and ablation of LVS-related arrhythmias.
Background: Many patients with persistent atrial fibrillation (PsAF) have progressed from an initial paroxysmal phenotype; however, there are patients in whom atrial fibrillation (AF) is persistent at diagnosis. Relatively little is known about this subgroup, but prior observational studies have suggested these patients have worse outcomes with ablation.
Objectives: This study sought to: 1) assess demographic and electrophysiologic characteristics of patients with PsAF at first diagnosis compared with those with who have progressed from paroxysmal atrial fibrillation (PAF); and 2) assess the impact of pattern of AF at diagnosis on recurrence post ablation.
Article Synopsis
- The study investigates the effect of the time from atrial fibrillation (AF) diagnosis to catheter ablation (DAT) on outcomes for patients with both AF and left ventricular systolic dysfunction (LVSD).
- Results show that a shorter DAT (less than 1 year) leads to better clinical outcomes, including higher rates of being free from arrhythmias and improved left ventricular ejection fraction (LVEF) after 12 months.
- The findings suggest that earlier catheter ablation in patients with AF and LVSD is linked to fewer hospitalizations and a better overall prognosis.
Background And Aims: Posterior wall isolation (PWI) is commonly incorporated into catheter ablation (CA) strategies for persistent atrial fibrillation (AF) in an attempt to improve outcomes. In the CAPLA randomized study, adjunctive PWI did not improve freedom from atrial arrhythmia at 12 months compared with pulmonary vein isolation (PVI) alone. Whether additional PWI reduces arrhythmia recurrence over the longer term remains unknown.
View Article and Find Full Text PDFDiagnosis to Ablation in Persistent AF: Any Time Can Be a Good Time to Ablate.
JACC Clin Electrophysiol
July 2024
Article Synopsis
- A study was conducted to evaluate how the time from diagnosis to catheter ablation (DAT) affects the recurrence of atrial fibrillation (AF) in patients.
- The trial involved 334 patients divided into quartiles based on their DAT, with results showing varying AF recurrence rates; longer DAT generally correlated with higher recurrence.
- Despite this trend, overall quality of life improved significantly for all patients, indicating positive outcomes regardless of the length of the DAT, with only the longest DAT group showing a statistically significant risk of recurrence.
Article Synopsis
- This study analyzes patterns of atrial fibrillation (AF) recurrence in patients with persistent AF (PsAF) after catheter ablation, revealing that nearly half of participants experienced recurrence within 12 months.
- Findings show that most recurrences were paroxysmal rather than persistent, and patients with PsAF faced higher healthcare costs and lower quality of life.
- The study highlights the impact of AF recurrence on health outcomes, emphasizing the need for effective strategies to manage recurrent PsAF post-ablation.
Background: Linear and complex electrogram ablation (LCEA) beyond pulmonary vein isolation (PVI) is associated with an increase in left atrial macro-re-entrant tachycardias (LAMTs). Posterior wall isolation (PWI) is increasingly performed to improve AF ablation outcomes. However, the impact of PWI on the incidence of LAMT is unknown.
View Article and Find Full Text PDFBackground: Sex-specific outcomes after catheter ablation (CA) for atrial fibrillation (AF) have reported conflicting findings.
Objective: We examined the impact of female sex on outcomes in patients with persistent AF (PsAF) from the Catheter Ablation for Persistent Atrial Fibrillation: A Multicentre Randomized Trial of Pulmonary Vein Isolation vs PVI with Posterior Left Atrial Wall Isolation (CAPLA) randomized trial.
Methods: A total of 338 patients with PsAF were randomized to pulmonary vein isolation (PVI) or PVI with posterior wall isolation (PWI).
Importance: Catheter ablation for patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) is associated with improved left ventricular ejection fraction (LVEF) and survival compared with medical therapy. Nonrandomized studies have reported improved success with posterior wall isolation (PWI).
Objective: To determine the impact of pulmonary vein isolation (PVI) with PWI vs PVI alone on outcomes in patients with HFrEF.
Background: Pulmonary vein isolation (PVI) is less effective in patients with persistent atrial fibrillation (PsAF). Adjunctive ablation targeting low voltage areas (LVAs) may improve arrhythmia outcomes.
Objectives: This study aims to compare the outcomes of adding posterior wall isolation (PWI) to PVI, vs PVI alone in PsAF patients with posterior wall LVAs.
Background: Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs.
View Article and Find Full Text PDFArticle Synopsis
- Aberrant ventricular conduction, a concept introduced over 100 years ago, is often misunderstood despite advancements in cardiac science, as it primarily originates from the His-Purkinje system's physiological refractoriness rather than true conduction system disease.
- This phenomenon can present itself through various patterns such as premature atrial ectopics and the Ashman phenomenon, which complicate the diagnosis and management of broad complex tachycardia.
- Recognizing and differentiating aberrant ventricular conduction from ventricular tachyarrhythmias is crucial, as they have different treatment strategies and prognostic outcomes; the review aims to clarify ECG characteristics for precise interpretation.
Background: Patients with heart failure with preserved ejection fraction (HFpEF) frequently develop atrial fibrillation (AF). There are no randomized trials examining the effects of AF ablation on HFpEF outcomes.
Objectives: The aim of this study is to compare the effects of AF ablation vs usual medical therapy on markers of HFpEF severity, including exercise hemodynamics, natriuretic peptide levels, and patient symptoms.
Importance: Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison.
View Article and Find Full Text PDFAims: Epidemiological studies report the beneficial effects of habitual coffee consumption on incident arrhythmia, cardiovascular disease (CVD), and mortality. However, the impact of different coffee preparations on cardiovascular outcomes and survival is largely unknown. The aim of this study was to evaluate associations between coffee subtypes on incident outcomes, utilizing the UK Biobank.
View Article and Find Full Text PDFBackground: Observational studies report that obstructive sleep apnea (OSA) is associated with an increasingly remodeled atrial substrate in atrial fibrillation (AF). However, the impact of OSA management on the electrophysiologic substrate has not been evaluated.
Objectives: In this study, the authors sought to determine the impact of OSA management on the atrial substrate in AF.
Background: Mitral valve prolapse (MVP) is relatively common condition and while generally benign a small subset of patient suffers from malignant ventricular arrhythmias (MVA) and sudden cardiac death (SCD).
Method And Material: We report three cases of mitral valve prolapse, mitral regurgitation and malignant ventricular arrhythmias refractory to medical therapy, who had surgical cryoablation at the time of surgery on the mitral valve.
Results: During a follow-up period ranging from 3 to 11 years all three patients have remained free of ventricular arrhythmias and cryoablation lesions targeting the base of the papillary muscles have not caused any detrimental effect on the valve function.
Background: The success of pulmonary vein isolation (PVI) is reduced in persistent AF (PsAF) compared to paroxysmal AF. Adjunctive ablation strategies have failed to show consistent incremental benefit over PVI alone in randomized studies. The left atrial posterior wall is a potential source of non-PV triggers and atrial substrate which may promote the initiation and maintenance of PsAF.
View Article and Find Full Text PDFBackground: Catheter ablation is highly effective for atrioventricular nodal re-entrant tachycardia (AVNRT). Generally junctional rhythm (JR) is an accepted requirement for successful ablation however there is a lack of detailed prospective studies to determine the characteristics of JR and the impact on slow pathway conduction.
Methods: Multicentre prospective observational study evaluating the impact of individual radiofrequency (RF) applications in typical AVNRT (slow/fast).
Aims: Obstructive sleep apnoea (OSA) associates with atrial fibrillation (AF), but the relationship of OSA severity and AF phenotype with the atrial substrate remains poorly defined. We sought to define the atrial substrate across the spectrum of OSA severity utilizing high-density mapping.
Methods And Results: Sixty-six consecutive patients (male 71%, age 61 ± 9) having AF ablation (paroxysmal AF 36, persistent AF 30) were recruited.
Aims: Prior studies have described a variety of mechanisms for atrial fibrillation (AF) originating in the right atrium (RA). In this study, we report a series of patients in whom an extensive right atrial free wall low-voltage zone (LVZ) served as the AF substrate.
Methods And Results: Five patients with a clinical syndrome of paroxysmal AF and atrial tachycardia (AT) underwent electrophysiologic evaluation.