Cardiac Resynchronization With Sequential Biventricular Pacing for the Treatment of Moderate-to-Severe Heart Failure

ObjectivesThe InSync III study evaluated sequential cardiac resynchronization therapy (CRT) in patients with moderate-to-severe heart failure and prolonged QRS.BackgroundSimultaneous CRT improves hemodynamic and clinical performance in patients with moderate-to-severe heart failure (HF) and a wide QRS. Recent evidence suggests that sequentially stimulating the ventricles might provide additional benefit.MethodsThis multicenter, prospective, nonrandomized, six-month trial enrolled a total of 422 patients to determine the effectiveness of sequential CRT in patients with New York Heart Association (NYHA) functional class III or IV HF and a prolonged QRS. The study evaluated: whether patients receiving sequential CRT for six months experienced improvement in 6-min hall walk (6MHW) distance, NYHA functional class, and quality of life (QoL) over control group patients from the reported Multicenter InSync Randomized Clinical Evaluation (MIRACLE) trial; whether sequential CRT increased stroke volume compared to simultaneous CRT; and whether an increase in stroke volume translated into greater clinical improvements compared to patients receiving simultaneous CRT.ResultsInSync III patients experienced greater improvement in 6MHW, NYHA functional class, and QoL at six months compared to control (all p < 0.0001). Optimization of the sequential pacing increased (median 7.3%) stroke volume in 77% of patients. No additional improvement in NYHA functional class or QoL was seen compared to the simultaneous CRT group; however, InSync III patients demonstrated greater exercise capacity.ConclusionsSequential CRT provided most patients with a modest increase in stroke volume above that achieved during simultaneous CRT. Patients receiving sequential CRT had improved exercise capacity, but no change in functional status or QoL

Elucidating the Power in Empowerment and the Participation in Participatory Action Research: A Story About Research Team and Elementary School Change

Community psychologists are increasingly using Participatory Action Research (PAR) as a way to promote social justice by creating conditions that foster empowerment. Yet, little attention has been paid to the differences between the power structure that PAR advocates and the local community power structures. This paper seeks to evaluate the level of participation in a PAR project for multiple stakeholder groups, determine how PAR was adjusted to better fit community norms, and whether our research team was able to facilitate the emergence of PAR by adopting an approach that was relevant to the existing power relations. We conclude that power differences should not be seen as roadblocks to participation, but rather as moments of opportunity for the researchers to refine their methods and for the community and the community psychologist to challenge existing power structures

Deficits in narrative abilities in child British Sign Language users with specific language impairment

This study details the first ever investigation of narrative skills in a group of 17 deaf signing children who have been diagnosed with disorders in their British Sign Language development compared with a control group of 17 deaf child signers matched for age, gender, education, quantity, and quality of language exposure and non-verbal intelligence. Children were asked to generate a narrative based on events in a language free video. Narratives were analysed for global structure, information content and local level grammatical devices, especially verb morphology. The language-impaired group produced shorter, less structured and grammatically simpler narratives than controls, with verb morphology particularly impaired. Despite major differences in how sign and spoken languages are articulated, narrative is shown to be a reliable marker of language impairment across the modality boundaries

Communication behavior and sensory mechanisms in weakly electric fishes

Teleost freshwater fishes of the orders Mormyriformes (the elephantfishes plus Gymnarchus from Africa) and Gymnotiformes (the knifefishes from South America) are both electrogenic and electroreceptive. These fishes' electric system has a motor part, the electric organ, and a sensory part, the cutaneous electroreceptors that project to large, specialized brain areas. The electric systems of both groups of fishes, although evolved independently, are adapted to the same two functions, nocturnal electrolocation and communication. Weakly electric fishes discharge their electric organs in a pulselike or in a wavelike fashion ("buzzers" and "hummers," respectively). Whether a species is a hummer or a buzzer does not appear to be correlated with ecology but is strongly linked to phylogeny. There are representatives of both discharge types on both continents where these fishes are found. The elephantfishes (Mormyridae, about 200 species) are, apparently, all pulse fishes, whereas the related, monospecific Gymnarchus (Gymnarchidae) is the only known African wave fish. There are five families of South American knifefishes, with the majority of the 70 or so species being hummers, usually discharging at extremely constant frequencies (about 50- 1800 Hz). The sensory mechanisms of social communication, as studied by behavioral means, are reviewed in this chapter with the question of mechanisms of reproductive isolation in mind. The chapter focuses on the electric organ discharge as the basic communication unit, and on the frequency, repetition rate, or temporal patterns of discharges. In both wave and pulse fishes the frequencies or repetition rates of discharges are not usually species-specific but are species-characteristic, because of more or less broad overlap between two or more species (depending on the local community of species). Electrosensory discrimination thresholds for frequency and intensity are unusually low in a wave fish, lower by far than those for other acoustico-lateral senses of aquatic lower vertebrates, rivaling the discrimination thresholds for audition in the most sensitive mammals (e.g., the human). A similar conclusion applies for the pulse rate sensitivity of a mormyrid. Species specificity becomes apparent when more information about the discharge activity is considered. In the case of pulse fishes, especially mormyrids, this comprises temporal patterns of discharges, which also vary greatly according to behavioral context (like aggression, escape, courtship, feeding, etc.); these fishes have an interdischarge interval code of communication. In the case of wave fishes, various types of frequency modulations and brief, repetitive discharge stops occur. Also, wave fishes may engage in "phase coupling" and "jamming avoidance," maneuvers that involve precise interaction with another fish's discharges. The degree ' of species specificity of a fish's discharge activity is usually enhanced by features of the waveform of a single discharge; this is true in both pulse and wave fishes. Usually there is considerable intraspecific variability of discharge waveforms, and there are also examples of sexual dimorphism. At least a few species can discriminate the individually variable pulse or wave discharge waveforms of their species. In a wave fish, a sensory mechanism based on the temporal analysis of beat patterns can explain the observed results. This new sensory capacity detects the phase modulation within a beat, which always occurs when the wave discharges of two fish mix in the water. In pulse fishes, several hypothetical sensory mechanisms for the discrimination of intraspecific pulse waveforms have been proposed but it is not yet clear which is generally involved. In any case, the sensitivity of weakly electric fishes to the fine detail of their discharges shows that the electrosensory world is much more colorful than could be imagined until recently

Communication and Waveform Analysis in Weakly Electric Fishes With Special Emphasis on Mormyrids

African snoutfishes and South American knifefishes communicate by weak, species-specific electric organ discharges (EODs) in the form of pulses or continuous waves. Both snoutfishes and knifefishes are highly sensitive to the waveform of EODs that, unlike ourselves for acoustical signals, trained fish discriminate even when identical in spectral composition. Field studies of close relatives in neighboring systems have advanced our understanding of ecology and evolution of snoutfishes and knifefishes and their electric sense