Characterization of onset mechanism and waveform analysis in patients with atrial fibrillation using a high-resolution noncontact mapping system

INTRODUCTION: Information on the spatiotemporal organization of atrial activity at the onset of atrial fibrillation (AF) is limited. METHODS AND RESULTS: The study consisted of 26 consecutive patients (22 men and 4 women; mean age 56 +/- 9 years) with AF in whom the left atrium (LA) was mapped using a noncontact mapping system. At the onset of AF, the AF cycle lengths and wavefronts were analyzed at the site of origin of the triggering atrial premature complex (APC) and five predefined sites within the LA (superior, anterior, posterior, lateral, and septal walls). If repetitive activity was observed at the site of origin of APCs, triggered AF episodes were considered as focally driven. APCs that induced AF had shorter coupling intervals than APCs that did not induce AF (300 +/- 41 msec vs 392 +/- 64 msec, P < 0.001). Immediately after AF onset, repetitive firing was crucial for maintenance of arrhythmia in 52 (80%) of 65 AF episodes. In 13 AF onset episodes (20%), AF was maintained by other mechanisms. The number of LA wavefronts after AF onset was lower in focally driven AF episodes compared with episodes in which no focally driven activity was observed (1.9 +/- 0.6 v. 2.3 +/- 2.3 wavefronts, P < 0.05). After the onset of AF, the posterior wall of the LA showed the earliest disorganized activity (after 5.2 +/- 3.1 cycles). CONCLUSION: In the majority of AF episodes (80%), repetitive firing from the triggering foci may play an important role in maintaining AF immediately after arrhythmia onset. In 20% of the episodes, AF at early stages seems to be maintained by other mechanisms. The capability of APCs to induce AF depends on the coupling interval and the focus localization. The posterior wall of the LA shows the earliest disorganization of wavefronts at the onset of AF.     

Physical inactivity in patients with rheumatoid arthritis: data from twenty-one countries in a cross-sectional, international study

OBJECTIVE: Regular physical activity is associated with decreased morbidity and mortality. Traditionally, patients with rheumatoid arthritis (RA) have been advised to limit physical exercise. We studied the prevalence of physical activity and associations with demographic and disease-related variables in patients with RA from 21 countries. METHODS: The Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST-RA) is a cross-sectional study that includes a self-report questionnaire and clinical assessment of nonselected consecutive outpatients with RA who are receiving usual clinical care. Frequency of physical exercise (>or=30 minutes with at least some shortness of breath, sweating) is queried with 4 response options: >or=3 times weekly, 1-2 times weekly, 1-2 times monthly, and no exercise. RESULTS: Between January 2005 and April 2007, a total of 5,235 patients from 58 sites in 21 countries were enrolled in QUEST-RA: 79% were women, >90% were white, mean age was 57 years, and mean disease duration was 11.6 years. Only 13.8% of all patients reported physical exercise>or=3 times weekly. The majority of the patients were physically inactive with no regular weekly exercise: >80% in 7 countries, 60-80% in 12 countries, and 45% and 29% in 2 countries, respectively. Physical inactivity was associated with female sex, older age, lower education, obesity, comorbidity, low functional capacity, and higher levels of disease activity, pain, and fatigue. CONCLUSION: In many countries, a low proportion of patients with RA exercise. These data may alert rheumatologists to motivate their patients to increase physical activity levels.     

Chitinase 3–like–1 and its receptors in Hermansky-Pudlak syndrome–associated lung disease

Hermansky-Pudlak syndrome (HPS) comprises a group of inherited disorders caused by mutations that alter the function of lysosome-related organelles. Pulmonary fibrosis is the major cause of morbidity and mortality in patients with subtypes HPS-1 and HPS-4, which both result from defects in biogenesis of lysosome-related organelle complex 3 (BLOC-3). The prototypic chitinase-like protein chitinase 3–like–1 (CHI3L1) plays a protective role in the lung by ameliorating cell death and stimulating fibroproliferative repair. Here, we demonstrated that circulating CHI3L1 levels are higher in HPS patients with pulmonary fibrosis compared with those who remain fibrosis free, and that these levels associate with disease severity. Using murine HPS models, we also determined that these animals have a defect in the ability of CHI3L1 to inhibit epithelial apoptosis but exhibit exaggerated CHI3L1-driven fibroproliferation, which together promote HPS fibrosis. These divergent responses resulted from differences in the trafficking and effector functions of two CHI3L1 receptors. Specifically, the enhanced sensitivity to apoptosis was due to abnormal localization of IL-13Rα2 as a consequence of dysfunctional BLOC-3–dependent membrane trafficking. In contrast, the fibrosis was due to interactions between CHI3L1 and the receptor CRTH2, which trafficked normally in BLOC-3 mutant HPS. These data demonstrate that CHI3L1-dependent pathways exacerbate pulmonary fibrosis and suggest CHI3L1 as a potential biomarker for pulmonary fibrosis progression and severity in HPS.     

Disclosure of Microbicide Gel Use to Sexual Partners: Influence on Adherence in the CAPRISA 004 Trial

Young women in sub-Saharan Africa are disproportionately affected by HIV, making the development of women initiated and controlled methods of prevention, including microbicides, a priority. Adherence is pivotal to microbicide efficacy and partner related factors are known to impact adherence. An analysis of disclosure of gel use to sexual partners and adherence in CAPRISA 004 women was conducted to better understand this relationship. Partner disclosure was significantly associated with a modest 4.2 % increased adherence (71.0 vs. 66.8 %, p = 0.03). Most women rated the experience of disclosure as positive, despite 6.7 % of partners expressing a negative reaction.Participants who disclosed were more likely to reside with their regular partner (14.4 vs. 8.4 %; p = 0.01) and reported consistent condom use at baseline (32.9 vs. 20.9 %; p < 0.01). Partner disclosure needs to be better understood as a potential facilitator or barrier to microbicide adherence.     

Respiratory management of infants with chronic neonatal lung disease beyond the NICU: A position statement from the Thoracic Society of Australia and New Zealand*

Chronic neonatal lung disease (CNLD) is defined as continued need for any form of respiratory support (supplemental oxygen and/or assisted ventilation) beyond 36 weeks PMA. Low‐flow supplemental oxygen facilitates discharge from hospital of infants with CNLD who are hypoxic in air and is widely used despite lack of evidence on the most appropriate minimum mean target oxygen saturations. Furthermore, there are minimal data to guide the home monitoring, titration or weaning of supplemental oxygen in these infants. The purpose of this position statement is to provide a guide for the respiratory management of infants with CNLD, with special emphasis on role and logistics of supplemental oxygen therapy beyond the NICU stay. Reflecting a variety of clinical practices and infant comorbidities (presence of pulmonary hypertension, retinopathy of prematurity and adequacy of growth), it is recommended that the minimum mean target range for SpO₂ during overnight oximetry to be 93–95% with less than 5% of total recording time to be below 90% SpO₂. Safety of short‐term disconnection from supplemental oxygen should be assessed before discharge, with majority of infants with CNLD not ready for discharge until supplemental oxygen requirement is ≤0.5 L/min. Sleep‐time assessment of oxygenation with continuous overnight oximetry is recommended when weaning supplemental oxygen. Palivizumab is considered safe and effective for the reduction of hospital admissions with RSV infection in this group. This statement would be useful for paediatricians, neonatologists, respiratory and sleep physicians and general practitioners managing children with CNLD.     

Motivation for and adherence to growth hormone replacement therapy in adults with hypopituitarism: the patients‘ perspective

Pituitary - While reasons for non-adherence in children requiring growth hormone (GH) replacement (GH-Rx) are well researched, few studies have investigated adherence in adult GH deficient...     

TIED TOGETHER: BUILDING RELATIONAL WELL‐BEING AND REDUCING SOCIAL ISOLATION THROUGH PLACE‐BASED PARENT EDUCATION

Recent research has begun to shed light on the role community organizations can play in fostering relational well‐being, particularly among low‐income parents living high‐poverty neighborhoods. However, less well understood are the organizational, programmatic, and neighborhood factors that contribute to the formation of new social network connections among participants in these settings or the nature of connections developed. This qualitative study examines the efforts of one neighborhood‐based human service organization to counter the effects of social isolation through a place‐based parent education initiative. Findings from 69 interviews suggest that for participants the program served as transformative learning environment that challenged existing narratives about public housing residents and fostered the development of a positive shared identity as parents. Formal structures and informal opportunities in the neighborhood supported the development and maintenance of new social connections and served as the foundation for an ongoing community of practice among participants.