Three dimensional reconstruction to visualize atrial fibrillation activation patterns on curved atrial geometry.

BACKGROUND: The rotational activation created by spiral waves may be a mechanism for atrial fibrillation (AF), yet it is unclear how activation patterns obtained from endocardial baskets are influenced by the 3D geometric curvature of the atrium or 'unfolding' into 2D maps. We develop algorithms that can visualize spiral waves and their tip locations on curved atrial geometries. We use these algorithms to quantify differences in AF maps and spiral tip locations between 3D basket reconstructions, projection onto 3D anatomical shells and unfolded 2D surfaces. METHODS: We tested our algorithms in N = 20 patients in whom AF was recorded from 64-pole baskets (Abbott, CA). Phase maps were generated by non-proprietary software to identify the tips of spiral waves, indicated by phase singularities. The number and density of spiral tips were compared in patient-specific 3D shells constructed from the basket, as well as 3D maps from clinical electroanatomic mapping systems and 2D maps. RESULTS: Patients (59.4±12.7 yrs, 60% M) showed 1.7±0.8 phase singularities/patient, in whom ablation terminated AF in 11/20 patients (55%). There was no difference in the location of phase singularities, between 3D curved surfaces and 2D unfolded surfaces, with a median correlation coefficient between phase singularity density maps of 0.985 (0.978-0.990). No significant impact was noted by phase singularities location in more curved regions or relative to the basket location (p>0.1). CONCLUSIONS: AF maps and phase singularities mapped by endocardial baskets are qualitatively and quantitatively similar whether calculated by 3D phase maps on patient-specific curved atrial geometries or in 2D. Phase maps on patient-specific geometries may be easier to interpret relative to critical structures for ablation planning.

Dynamic Atlas-Based Segmentation and Quantification of Neuromelanin-Rich Brainstem Structures in Parkinson Disease.

We present a dynamic atlas composed of neuromelanin-enhanced magnetic resonance brain images of 40 healthy subjects. The performance of this atlas is evaluated on the fully automated segmentation of two paired neuromelanin-rich brainstem healthy structures: the substantia nigra pars compacta and the locus coeruleus. We show that our dynamic atlas requires in average 60% less images and, therefore, 60% less computation time than a static multi-image atlas while achieving a similar segmentation performance. Then, we show that by applying our dynamic atlas, composed of healthy subjects, to the segmentation and neuromelanin quantification of a set of brain images of 39 Parkinson disease patients, we are able to find significant quantitative differences in the level of neuromelanin between healthy subjects and Parkinson disease patients, thus opening the door to the use of these structures as image biomarkers in future computer aided diagnosis systems for the diagnosis of Parkinson disease.

Importance of Evaluating Cardiovascular Risk and Hepatic Fibrosis in Patients With Newly Diagnosed Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is a well-recognized health problem, with an estimated worldwide prevalence of 25%.1 It is associated with metabolic syndrome (MetSx) and complications such as cirrhosis and hepatocellular carcinoma. However, the main cause of death in patients with NAFLD is derived from cardiovascular disease, and outcome seems to be determined by the degree of hepatic fibrosis.2 The prevalence of NAFLD and associated cardiovascular risk factors in asymptomatic patients in Mexico are poorly documented, despite having one of the highest rates of obesity and metabolic syndrome worldwide.3.

Hybrid treatment of dysphagia lusoria: right carotid to subclavian bypass and endovascular insertion of an Amplatzer II Vascular Plug

Compression of the esophagus by a retroesophageal aberrant right subclavian artery (ARSA) is a rare cause of dysphagia. We present the case of a 47-year-old female with symptoms of progressive dysphagia diagnosed with dysphagia lusoria using barium swallow and contrast computed tomography and successfully treated with a hybrid procedure: right carotid to subclavian bypass and endovascular insertion of an Amplatzer II Vascular Plug through the right superficial femoral artery. We consider this approach safer, less invasive and more complete to avoid recurrent dysphagia (AU)

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Hybrid treatment of dysphagia lusoria: right carotid to subclavian bypass and endovascular insertion of an Amplatzer II Vascular Plug.

Compression of the esophagus by a retroesophageal aberrant right subclavian artery (ARSA) is a rare cause of dysphagia. We present the case of a 47-year-old female with symptoms of progressive dysphagia diagnosed with dysphagia lusoria using barium swallow and contrast computed tomography and successfully treated with a hybrid procedure: right carotid to subclavian bypass and endovascular insertion of an Amplatzer II Vascular Plug through the right superficial femoral artery. We consider this approach safer, less invasive and more complete to avoid recurrent dysphagia.