This work presents the results of a new tool for 3-D segmentation, quantification and visualization of cardiac left atrium fibrosis, based on late gadolinium enhancement magnetic resonance imaging (LGE-MRI), for stratifying patients with atrial fibrillation (AF) that are candidates for radio-frequency catheter ablation. In this study 10 consecutive patients suffering AF with different grades of atrial fibrosis were considered. LGE-MRI and magnetic resonance angiography (MRA) images were used to detect and quantify fibrosis of the left atrium using a threshold and 2-D skeleton based approach. Quantification and 3-D volumetric views of atrial fibrosis were compared with quantification and 3-D bipolar voltage maps measured with an electro-anatomical mapping (EAM) system, the clinical reference standard technique for atrial substrate characterization. Segmentation and quantification of fibrosis areas proved to be clinically reliable among all different fibrosis stages. The proposed tool obtains discrepancies in fibrosis quantification less than 4% from EAM results and yields accurate 3-D volumetric views of fibrosis of left atrium. The novel 3-D visualization and quantification tool based on LGE-MRI allows detection of cardiac left atrium fibrosis areas. This noninvasive method provides a clinical alternative to EAM systems for quantification and localization of atrial fibrosis.

Rheumatoid arthritis (RA) is associated with higher risk of heart failure. Several studies report that left ventricular (LV) diastolic dysfunction (LVDD), a silent precursor of heart failure, is widely present in RA patients. Very little is known about the factors related to the development of LVDD in this disease. In this study we assessed the incidence and the predictors of new-onset LVDD in RA patients. Two-hundred-ninety-five adults with RA without overt cardiac disease were prospectively analyzed from March 2014 to March 2015 by Doppler echocardiography. Among the 295 subjects evaluated, 217 (73.6%) had normal LV diastolic function and represented the final study population. At 1-year follow-up, 53 of 217 patients (24%) developed LVDD, which was of degree I (mild dysfunction) in all of them. By multivariate logistic regression analysis, lower E/A ratio of transmitral flow (ratio between the peak velocity of early diastolic “E” wave and late diastolic “A” wave of transmitral flow) was independently associated with new-onset LVDD [OR 0.17 (CI 0.09-0.57)], together with older age and higher systolic blood pressure. In a clinical predictive model derived from multivariate analysis, the new-onset LVDD rate event ranged from 0% (patients without any factor) to 75% (patients in whom the three predictors coexisted). A significant portion of patients with RA without overt cardiac disease develop LVDD at 1-year follow-up. This condition can be predicted by a simple clinical model which could improve the clinical management and the prognostic stratification of patients with RA.

Despite the small size of the sample studied, the LE-MR sequence proved more useful for excluding the presence of AF than for confirming its existence. Identification of AF prior to RFCA is paramount to select those patients who are truly amenable to the ablation procedure, which is expensive and not entirely free of risks.

The prevalence of p.(Ser64Arg) mutation is low in the general population as is the prevalence of atrial fibrillation in mutation carriers (1/10). Atrial fibrillation in the affected mutated patient was lone at onset and progressively evolved with peculiar electrophysiological patterns.

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