Role of myocardial T1 mapping in arrhythmogenic right ventricular cardiomyopathy

Background

T1 mapping by cardiovascular magnetic resonance (CMR) is an accurate tool to assess myocardial extracellular space with wider clinical applications in the aetiological characterization of cardiomyopathies. The aims of the study were to explore a possible role of myocardial T1 mapping in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and in first-degree relatives at risk and to investigate the possible relationship between left ventricular (LV) involvement at CMR and ECG features.

Methods

Thirty patients with ARVC (47% males, mean age 42±22 years) and 59 first-degree relatives who did not fulfil ARVC diagnostic Task Force criteria, underwent full diagnostic work-up including CMR with native and post-contrast T1 mapping.

Results

The CMR was abnormal in 26 (86%) patients with ARVC. The RV was affected in isolation in 13 (43%) patients. Prior to T1 mapping assessment, 2 (7%) patients exhibited isolated LV involvement and 11 (36%) patients showed features of biventricular disease. Left ventricular involvement was manifested as detectable LV late gadolinium enhancement (LGE) in 12 out of 13 cases. According to pre-specified septal T1 mapping thresholds, 11 (37%) patients showed abnormally high native T1 values. Myocardial T1 mapping was higher than normal in 5 (17%) patients who would have been classified as exhibiting a normal LV by conventional imaging. The proportion of patients with abnormal T1 values was similar in patients with or without LGE. Myocardial T1 mapping was higher than normal in 22 (37%) of the 59 first-degree relatives.

Conclusions

Native and/or post contrast myocardial T1 values are raised in almost half of patients with ARVC and in a similar proportion of unaffected first-degree relatives. T1 mapping offers the potential for early detection of LV involvement in patients with ARVC and in first-degree relatives at risk.

Funding Acknowledgement

Type of funding source: None

A versatile robotic platform for the design of natural, three-dimensional reaching and grasping tasks in monkeys

OBJECTIVE

Translational studies on motor control and neurological disorders require detailed monitoring of sensorimotor components of natural limb movements in relevant animal models. However, available experimental tools do not provide a sufficiently rich repertoire of behavioral signals. Here, we developed a robotic platform that enables the monitoring of kinematics, interaction forces, and neurophysiological signals during user-defined upper limb tasks for monkeys.

APPROACH

We configured the platform to position instrumented objects in a three-dimensional workspace and provide an interactive dynamic force-field.

MAIN RESULTS

We show the relevance of our platform for fundamental and translational studies with three example applications. First, we study the kinematics of natural grasp in response to variable interaction forces. We then show simultaneous and independent encoding of kinematic and forces in single unit intra-cortical recordings from sensorimotor cortical areas. Lastly, we demonstrate the relevance of our platform to develop clinically relevant brain computer interfaces in a kinematically unconstrained motor task.

SIGNIFICANCE

Our versatile control structure does not depend on the specific robotic arm used and allows for the design and implementation of a variety of tasks that can support both fundamental and translational studies of motor control.

Assessment of person-to-person transmission of hantavirus pulmonary syndrome in a Chilean hospital setting

Person-to-person transmission of Andes hantavirus among healthcare workers was reported in Argentina for the first time in 1996. To determine whether such transmission of the virus occurred during a 1997 outbreak of hantavirus pulmonary syndrome (HPS) in southern Chile due to Andes virus, we conducted a serological and epidemiological study in the Coyhaique Regional Hospital, where the majority of HPS patients were admitted. Workers in every department of the hospital were evaluated for immunoglobulin G (IgG) and IgM hantavirus antibodies using the enzyme-linked immunosorbent assay (ELISA). A standardized questionnaire was used to determine the type and extent of exposure to HPS patients, as well as other potential risk factors and previous febrile respiratory illnesses requiring hospitalization. Less than half (44%) reported always using gloves when touching patients or their secretions; respiratory protection was not used. Of the 319 participants (87.9% of those eligible), 12 (3.7%) had IgG antibodies. This finding is consistent with the antibody prevalence in the community in which the participants lived. Of the 12 positive healthcare workers, six reported contact with HPS patients. A similar exposure was found in those who tested negative [6/140 (4%) compared to 6/179 (3%), P = 0.66]. There was no significant difference in the types of hospital activities performed or the number of hospitalizations for febrile respiratory illnesses between antibody-positive and antibody-negative individuals. These data suggest that there was no person-to-person transmission among healthcare workers during a recent outbreak of HPS in Southern Chile in 1997, despite the inconsistent use of any precautions against transmission.