Publications by authors named "Nathan S Burgon"
Objectives: The purpose of this study is to evaluate the spatial distribution of late gadolinium enhancement (LGE) of the left atrium (LA) by LGE-magnetic resonance imaging in an atrial fibrillation (AF) population.
Background: LGE of the LA can be a surrogate of pre-existing structural remodeling of LA.
Methods: LGE-magnetic resonance imaging scans were used for 160 patients with AF (mean age 66 ± 11 years) before AF ablation.
Objectives: This study hypothesized that left atrial structural remodeling (LA-TR) correlates with exercise capacity (EC) in a cohort of patients with atrial fibrillation (AF).
Background: Late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging provides a method of assessing LA-TR in patients with AF.
Methods: A total of 145 patients (32% female, mean age 63.
Background: Three-dimensional electroanatomic mapping (EAM) is routinely used to mark ablated areas during radiofrequency ablation. We hypothesized that, in atrial fibrillation (AF) ablation, EAM overestimates scar formation in the left atrium (LA) when compared to the scar seen on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI).
Methods And Results: Of the 235 patients who underwent initial ablation for AF at our institution between August 2011 and December 2012, we retrospectively identified 70 patients who had preprocedural magnetic resonance angiography merged with LA anatomy in EAM software and had a 3-month postablation LGE-MRI for assessment of scar.
Atrial fibrillation ablation outcome is predicted by left atrial remodeling on MRI.
Circ Arrhythm Electrophysiol
February 2014
Background: Although catheter ablation therapy for atrial fibrillation (AF) is becoming more common, results vary widely, and patient selection criteria remain poorly defined. We hypothesized that late gadolinium enhancement MRI (LGE-MRI) can identify left atrial (LA) wall structural remodeling (SRM) and stratify patients who are likely or not to benefit from ablation therapy.
Methods And Results: LGE-MRI was performed on 426 consecutive patients with AF without contraindications to MRI before undergoing their first ablation procedure and on 21 non-AF control subjects.
Background: Catheter ablation significantly improves the left ventricular (LV) function in patients with atrial fibrillation (AF) and LV systolic dysfunction. In this study, we compared the degree of left atrial structural remodeling (LA-SRM) in patients with normal versus reduced LV ejection fraction (LVEF). We also studied the impact of LA-SRM on LVEF improvement in patients undergoing ablation of AF.
View Article and Find Full Text PDFBackground: Magnetic resonance imaging (MRI) can visualize locations of both the ablation scar on the left atrium (LA) after atrial fibrillation (AF) ablation and epicardial fat pads (FPs) containing ganglionated plexi (GP).
Methods: We investigated 60 patients who underwent pulmonary vein antrum (PVA) isolation along with LA posterior wall and septal debulking for AF. FPs around the LA surface in well-known GP areas (which were considered as the substitution of GP areas around the LA) were segmented from the dark-blood MRI.
Objectives: This study tried to determine the association between left atrial (LA) fibrosis, detected using delayed-enhanced magnetic resonance imaging (DE-MRI), and the CHADS(2) score (point system based on individual clinical risk factors including congestive heart failure, hypertension, age, diabetes, and prior stroke) variables, specifically stroke.
Background: In patients with atrial fibrillation (AF), conventional markers for the risk of stroke base their higher predictive effect on clinical features, particularly previous stroke history, and not individual LA pathophysiological properties. We aimed to determine the association between LA fibrosis, detected using DE-MRI, and the CHADS(2) score variables, specifically stroke.
Background: Atrial fibrosis is a hallmark of atrial structural remodeling (SRM) and leads to structural and functional impairment of left atrial (LA) and persistence of atrial fibrillation (AF). This study was conducted to assess LA reverse remodeling after catheter ablation of AF in mild and moderate-severe LA SRM.
Methods: Catheter ablation was performed in 68 patients (age 62 ± 14 years, 68% males) with paroxysmal (n = 26) and persistent (n = 42) AF.
Background: Lone atrial fibrillation (AF) is thought to be a benign type or an early stage of the disease.
Objective: This study sought to compare the left atrium (LA) substrate using delayed-enhanced magnetic resonance imaging (DE-MRI) in patients with lone AF versus those with comorbidities.
Methods: Forty of 333 included patients met criteria for lone AF.
Background: We evaluated scar lesions after initial and repeat catheter ablation of atrial fibrillation (AF) and correlated these regions to low-voltage tissue on repeat electroanatomic mapping. We also identified gaps in lesion sets that could be targeted and closed during repeat procedures.
Methods And Results: One hundred forty-four patients underwent AF ablation and received a delayed-enhancement MRI at 3 months after ablation.
Background: Atrial fibrillation (AF) is a progressive condition that begins with hemodynamic and/or structural changes in the left atrium (LA) and evolves through paroxysmal and persistent stages. Because of limitations with current noninvasive imaging techniques, the relationship between LA structure and function is not well understood.
Methods And Results: Sixty-five patients (age, 61.
Background: Esophageal wall thermal injury after atrial fibrillation ablation is a potentially serious complication. However, no noninvasive modality has been used to describe and screen patients to examine whether esophageal wall injury has occurred. We describe a noninvasive method of using delayed-enhancement MRI to detect esophageal wall injury and subsequent recovery after atrial fibrillation ablation.
View Article and Find Full Text PDFIntroduction: Though pulmonary vein (PV) isolation has been widely adopted for treatment of atrial fibrillation (AF), recurrence rates remain unacceptably high with persistent and longstanding AF. As evidence emerges for non-PV substrate changes in the pathogenesis of AF, more extensive ablation strategies need further study.
Methods: We modified our PV antrum isolation procedure to include abatement of posterior and septal wall potentials.
Background: Atrial fibrillation (AF) is associated with diffuse left atrial fibrosis and a reduction in endocardial voltage. These changes are indicators of AF severity and appear to be predictors of treatment outcome. In this study, we report the utility of delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome.
View Article and Find Full Text PDFBackground: Atrial fibrillation (AF) ablation uses radiofrequency (RF) energy to induce thermal damage to the left atrium (LA) in an attempt to isolate AF circuits. This injury can be seen using delayed enhancement magnetic resonance imaging (DE-MRI).
Objective: The purpose of this study was to describe DE-MRI findings of the LA in the acute and chronic stages postablation.