OBJECTIVES
This study sought to assess the relationship between fibrosis and re-entrant activity in persistent atrial fibrillation (AF).
BACKGROUND
The mechanisms involved in sustaining re-entrant activity during AF are poorly understood.
METHODS
Forty-one patients with persistent AF (age 56 ± 12 years; 6 women) were evaluated. High-resolution electrocardiographic imaging (ECGI) was performed during AF by using a 252-chest electrode array, and phase mapping was applied to locate re-entrant activity. Sites of high re-entrant activity were defined as re-entrant regions. Late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) was performed at 1.25 × 1.25 × 2.5 mm resolution to characterize atrial fibrosis and measure atrial volumes. The relationship between LGE burden and the number of re-entrant regions was analyzed. Local LGE density was computed and characterized at re-entrant sites. All patients underwent catheter ablation targeting re-entrant regions, the procedural endpoint being AF termination. Clinical, CMR, and ECGI predictors of acute procedural success were then analyzed.
RESULTS
Left atrial (LA) LGE burden was 22.1 ± 5.9% of the wall, and LA volume was 74 ± 21 ml/m2. The number of re-entrant regions was 4.3 ± 1.7 per patient. LA LGE imaging was significantly associated with the number of re-entrant regions (R = 0.52, p = 0.001), LA volume (R = 0.62, p < 0.0001), and AF duration (R = 0.54, p = 0.0007). Regional analysis demonstrated a clustering of re-entrant activity at LGE borders. Areas with high re-entrant activity showed higher local LGE density as compared with the remaining atrial areas (p < 0.0001). Failure to achieve AF termination during ablation was associated with higher LA LGE burden (p < 0.001), higher number of re-entrant regions (p < 0.001), and longer AF duration (p = 0.008).
CONCLUSIONS
The number of re-entrant regions during AF relates to the extent of LGE on CMR, with the location of these regions clustering to LGE areas. These characteristics affect procedural outcomes of ablation.
• Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially treatable by surgery. • Dual-energy computed tomography (DECT) allows angiography and perfusion using a single acquisition. • Both DECT perfusion and angiography showed satisfactory diagnostic performance in CTEPH. • DECT perfusion was more accurate than angiography in identifying segmental abnormalities.
The purpose of this study was to evaluate the performance and complication rate of CT-guided percutaneous lung biopsy of pulmonary lesions using a coaxial automated biopsy device and to determine factors influencing the false negative rate for the diagnosis of malignancy. A prospective study of 605 consecutive biopsies performed in 595 patients was undertaken. The performances for the diagnosis of malignancy, for the specific diagnosis of benignity and the complication rate were calculated. Patients' characteristics and lesion and procedure variables were included in a logistic regression model and analyzed as potential predictive variables for occurrence of a false-negative diagnosis of malignancy. The sensitivity, specificity, positive predictive value and negative predictive value for a diagnosis of malignancy were 92.2, 99.1, 99.8 and 73.3%, respectively. A specific diagnosis of benignity was obtained in 43 cases (40%) biopsies. The pneumothorax rate was 17.4% (n = 105) with 3 (0.5%) requiring drainage. At multivariate analysis, the sole variable significantly associated with a higher rate of false negative diagnosis of malignancy was lesion size equal to or smaller than 10 mm in diameter. Using a coaxial automated device, CT-guided percutaneous biopsy of pulmonary lesions of size equal to or less than 10 mm in diameter provides a high diagnostic yield with an acceptable complication rate.
• Spatial resolution of lung MRI is limited using non-ultra-short TE MRI technique • Ultra-short echo time (UTE) technique enables submillimeter 3D-MRI of airways • 3D-UTE MRI shows very good concordance with CT in assessing cystic fibrosis • Radiation-free 3D-UTE MRI enables the Helbich-Bhalla scoring without a need for contrast injection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.