Feasibility of physiological pacing rate in cardiac resynchronization therapy.

Aims: Although cardiac resynchronization therapy (CRT) improves functional capacity in heart failure patients, a blunted heart rate (HR) response remains after treatment. So we aimed to evaluate the feasibility of the physiological pacing rate (PPR) in CRT patients.

Methods: A cohort of 30 clinical mildly symptomatic CRT patients underwent the six-minute walk test (6MWT).

Myocardial function reclassification: Echocardiographic strain patterns in patients with chronic Chagas cardiomyopathy and intraventricular dyssynchrony.

Background: We aimed to identify, among Chronic Chagas Cardiomyopathy (CCC) patients with left ventricular dysfunction (LVD) and non-left bundle branch block (non-LBBB), subgroups with different functional and mechanical patterns of global longitudinal strain (GLS) and intraventricular dyssynchrony (IVD) at rest and after exercise stress test, and reclassify them using a new echocardiographic approach.

Methodology: In this single-center cross-sectional study, 40 patients with CCC, left ventricular ejection fraction (LVEF) ≤ 35% and non-LBBB underwent rest echocardiography and then treadmill exercise stress echocardiography with GLS and IVD analysis. The sample was divided into four groups, based on GLS and IVD significant variation between rest and exercise: GLS + IVD+ (9 patients); GLS + IVD- (9 patients); GLS-IVD+ (10 patients); GLS-IVD- (10 patients).

Mangroves as traps for environmental damage to metals: The case study of the Fundão Dam.

This essay is a conceptual framework for testing the causal mechanisms of system degradation by metals in the mangrove ecosystem. The Fundão Dam collapse caused massive damage to the marine environment on the Southern Atlantic and Brazilian coast, reaching various kilometers from its origin, becoming a source of contamination. Along this Brazilian coast are vast mangrove areas with high biodiversity, different geomorphology, and distinct ecological functioning.

Estimation of the aboveground biomass and carbon stocks in open Brazilian Savannah developed on sandy soils.

Background: The Cerrado is the second largest biome in Brazil and the most biodiverse tropical savannah in the world and acts as a great sequester of atmospheric carbon. The lack of studies related to the quantification of its total biomass compromises the understanding of the dynamics of CO in this biome. Thus, it is relevant to develop studies aiming at obtaining accurate estimates of the carbon stock in the different phytophysiognomies that make the Cerrado, to include them in appropriate forest management models.

Preliminary evidence of age-dependent clinical signs associated with porcine circovirus 2b in experimentally infected CH3/Rockefeller mice.

Mice and rats are susceptible to porcine circovirus 2b (PCV2) infection under field and experimental conditions. However, whether PCV2 induces disease in rodents remains a matter of debate. The objectives of the present study were to determine whether PCV2-induced disease in mice is age-dependent and whether intranasally inoculated animals are able to infect animals they come into contact with.