Saturation recovery-prepared magnetic resonance angiography for assessment of left atrial and esophageal anatomy.

Objectives: Magnetic resonance angiography (MRA) has been established as an important imaging method in cardiac ablation procedures. In pulmonary vein (PV) isolation procedures, MRA has the potential to minimize the risk of severe complications, such as atrio-esophageal fistula, by providing detailed information on esophageal position relatively to cardiac structures. However, traditional non-gated, first-pass (FP) MRA approaches have several limitations, such as long breath-holds, non-uniform signal intensity throughout the left atrium (LA), and poor esophageal visualization.

Atrial fibrosis in non-atrial fibrillation individuals and prediction of atrial fibrillation by use of late gadolinium enhancement magnetic resonance imaging.

Introduction: Besides the traditional concept of atrial fibrillation (AF) perpetuating atrial structural remodeling, there is increasing evidence that atrial fibrosis might precede AF, highlighting the need for better characterization of the fibrotic substrate. We aimed to assess atrial fibrosis by use of late gadolinium enhancement magnetic resonance imaging (LGE-MRI) in non-AF individuals and to identify predisposing risk factors. A second aim was to establish a risk score for the prevalence of AF using atrial fibrosis in addition to established clinical variables.

Left atrial shape predicts recurrence after atrial fibrillation catheter ablation.

Introduction: Multiple markers left atrium (LA) remodeling, including LA shape, correlate with outcomes in atrial fibrillation (AF). Catheter ablation is an important treatment of AF, but better tools are needed to determine which patients will benefit. In this study, we use particle-based modeling to quantitatively assess LA shape, and determine to what degree it predicts AF recurrence after catheter ablation.

Exercise Capacity Correlates With Left Atrial Structural Remodeling as Detected by Late Gadolinium-Enhanced Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.

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.

Prognostic Implications of Left Ventricular Scar Determined by Late Gadolinium Enhanced Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.

Left ventricular (LV) scar identified by late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) is associated with adverse outcomes in coronary artery disease and cardiomyopathies. We sought to determine the prognostic significance of LV-LGE in atrial fibrillation (AF). We studied 778 consecutive patients referred for radiofrequency ablation of AF who underwent CMR.

Changes in left ventricular filling parameters following catheter ablation of atrial fibrillation.

Background: Atrial fibrillation (AF) is common in the setting of abnormal ventricular relaxation. We evaluated the association between ventricular relaxation grade and atrial fibrosis and examined the change in left ventricular filling parameters following catheter ablation.

Methods And Results: AF patients undergoing catheter ablation who had cardiac late gadolinium enhancement MRI (LGE-MRI) and echocardiographic examinations were included in the study.

Incidental LV LGE on CMR Imaging in Atrial Fibrillation Predicts Recurrence After Ablation Therapy.

Objectives: This study sought to evaluate the prognostic significance of left ventricular late gadolinium enhancement (LV-LGE) incidentally found in atrial fibrillation (AF) patients who undergo ablation therapy.

Background: LV-LGE provides prognostic information in patients with ischemic and nonischemic cardiomyopathies. However, data on the clinical significance of incidental LV-LGE in the AF population are limited.

Wideband late gadolinium enhanced magnetic resonance imaging for imaging myocardial scar without image artefacts induced by implantable cardioverter-defibrillator: a feasibility study at 3 T.

Aim: Late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is a useful tool for facilitating ventricular tachycardia (VT) ablation. Unfortunately, most VT ablation candidates often have prophylactic implantable cardioverter-defibrillator (ICD) and do not undergo cardiac MRI largely due to image artefacts generated by ICD. A prior study has reported success of 'wideband' LGE MRI for imaging myocardial scar without image artefacts induced by ICD at 1.

Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency.

Noninvasive diagnosis of chemotherapy related cardiotoxicity.

Chemotherapeutic agents reduce mortality and can prevent morbidity in a wide range of malignancies. These agents are, however, associated with toxicities of their own, and the treating physician must remain ever vigilant against the risk outgrowing the benefit of therapy. Thus, pre-treatment evaluation and monitoring for toxicity during and following administration is a fundamental tenet of oncologic practice.

Association of left atrial fibrosis detected by delayed-enhancement magnetic resonance imaging and the risk of stroke in patients with atrial fibrillation.

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.

Real-time magnetic resonance imaging-guided radiofrequency atrial ablation and visualization of lesion formation at 3 Tesla.

Background: Magnetic resonance imaging (MRI) allows visualization of location and extent of radiofrequency (RF) ablation lesion, myocardial scar formation, and real-time (RT) assessment of lesion formation. In this study, we report a novel 3-Tesla RT -RI based porcine RF ablation model and visualization of lesion formation in the atrium during RF energy delivery.

Objective: The purpose of this study was to develop a 3-Tesla RT MRI-based catheter ablation and lesion visualization system.

Evaluation of the left atrial substrate in patients with lone atrial fibrillation using delayed-enhanced MRI: implications for disease progression and response to catheter ablation.

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.

Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation.

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.

Estimating myocardial perfusion from dynamic contrast-enhanced CMR with a model-independent deconvolution method.

Background: Model-independent analysis with B-spline regularization has been used to quantify myocardial blood flow (perfusion) in dynamic contrast-enhanced cardiovascular magnetic resonance (CMR) studies. However, the model-independent approach has not been extensively evaluated to determine how the contrast-to-noise ratio between blood and tissue enhancement affects estimates of myocardial perfusion and the degree to which the regularization is dependent on the noise in the measured enhancement data. We investigated these questions with a model-independent analysis method that uses iterative minimization and a temporal smoothness regularizer.

New magnetic resonance imaging-based method for defining the extent of left atrial wall injury after the ablation of atrial fibrillation.

Objectives: We describe a noninvasive method of detecting and quantifying left atrial (LA) wall injury after pulmonary vein antrum isolation (PVAI) in patients with atrial fibrillation (AF). Using a 3-dimensional (3D) delayed-enhancement magnetic resonance imaging (MRI) sequence and novel processing methods, LA wall scarring is visualized at high resolution after radiofrequency ablation (RFA).

Background: Radiofrequency ablation to achieve PVAI is a promising approach to curing AF.

Quantitative myocardial distribution volume from dynamic contrast-enhanced MRI.

The objective of this study was to investigate if dynamic contrast-enhanced magnetic resonance imaging (MRI) can be used to quantitate the distribution volume (v(e)) in regions of normal and infarcted myocardium. v(e) reflects the volume of the extracellular, extravascular space within the myocardial tissue. In regions of the heart where an infarct has occurred, the loss of viable cardiac cells results in an elevated v(e) compared to normal regions.