Reference values of left atrial size and function according to age: should we redefine the normal upper limits?

Different cut-offs have been proposed for left atrial (LA) size. Furthermore, conflicting results have been reported about the influence of age on LA size and data on the impact of age on LA myocardial function are scanty. The aim of this study was to derive references values for LA size and function in healthy subjects and to evaluate the impact of age. We conducted a systematic literature search of MEDLINE database. We included only studies evaluating healthy subjects, with age ranged between 18 and 80 years. Parameters were compared among four age groups, < 30, 30–45, > 45–60, > 60 years. Three hundred twenty-six studies met the inclusion criteria and the final population consisted of 62,821 subjects. LA volume index (LAVi) did not differ among different age groups (p = 0.21). The normal upper limit of LAVi was 24 mL/m². LA reservoir function, measured by strain, did not differ among age groups (38 ± 3%, 32–43%; p = 0.74). Left ventricular (LV) size and function were not different among groups, except LV mass index. A decrease in E/A ratio and an increase in E/e′ ratio were found with advancing age (p < 0.0001 and p = 0.001, respectively). In healthy subjects the normal upper limit of LAVi was lower than that recommended and is not influenced by advancing age. Furthermore, also LA function measured by strain was not affected by age. The current reference values of LAVi should be used with caution when applied to healthy subjects.

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FixaTons: A collection of Human Fixations Datasets and Metrics for Scanpath Similarity

In the last three decades, human visual attention has been a topic of great interest in various disciplines. In computer vision, many models have been proposed to predict the distribution of human fixations on a visual input. Recently, thanks to the creation of large collections of data, machine learning algorithms have obtained state-of-the-art performance on the task of saliency map estimation. On the other hand, computational models of scanpath are much less studied. Works are often only descriptive or task specific. Computational models of scanpath with general purpose are present in the literature, but are then evaluated in tasks of saliency prediction, losing therefore information about the dynamics and the behaviour. This is due to the fact that the scanpath is harder to model because it must include the description of a dynamic. In addition to the difficulty of the problem itself, two technical reasons have limited the research. The first reason is the lack of robust and uniformly used set of metrics to compare the similarity between scanpath. The second reason is the lack of sufficiently large and varied scanpath datasets. In this report we want to help in both directions. We present FixaTons, a large collection of human scanpaths (and saliency maps). It comes along with a software library for easy data usage, statistics calculation and measures for scanpaths (and saliency maps) similarity.