The contribution of inspiratory muscles function to exercise limitation in heart failure: pathophysiological mechanisms Contribuição da musculatura inspiratória na limitação ao exercício na insuficiência cardíaca: mecanismos fisiopatológicos AbstractBackground: Heart failure induces histological, metabolic and functional adaptations in the inspiratory muscles. This inspiratory

In patients with severe autonomic dysfunction, water ingestion elicits an acute pressor response. Hypertension may be associated with changes in cardiovascular autonomic modulation, but there is no information on the acute effects of water ingestion in patients with hypertension. In this study, we compared the effect of acute water ingestion on haemodynamic and autonomic responses of hypertensive and normotensive individuals. Eight patients with mild hypertension were compared to 10 normotensive individuals. After 30 min resting in the supine position all subjects ingested 500 ml of water. At baseline and after water ingestion, venous blood samples for plasma volume determination were collected, and electrocardiographic tracings, finger blood pressure, forearm blood flow and muscle sympathetic nerve activity (MSNA) were obtained. Water ingestion resulted in similar and minor reduction in plasma volume. Systolic and diastolic blood pressure increased in both hypertensive (mean7s.d.: 19/1476/ 3 mm Hg) and normotensive subjects (17/1476/3 mm Hg). There was an increase in forearm vascular resistance and in MSNA. Heart rate was reduced (hypertensive: 571 beats/min, normotensive: 576 beats/min) and the high-frequency component of heart rate and systolic blood pressure variability was increased. In hypertensive and normotensive individuals, acute water ingestion elicits a pressor response, an effect that is most likely determined by an increased vasoconstrictor sympathetic activity, and is counterbalanced by an increase in blood pressure and heart rate vagal modulation.

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We hypothesized that heart failure patients with inspiratory muscle weakness (IMW) present greater peripheral chemoreflex responsiveness and augmented exercise ventilatory oscillation compared to patients with preserved inspiratory muscle strength. We studied 19 heart failure patients: 9 with IMW (maximal inspiratory pressure [PImax]<70% of predicted) and 10 with preserved inspiratory muscle strength. Inspiratory muscle strength was measured via pressure transducer. Peripheral chemoreflex was evaluated by the single-breath CO(2) test. Exercise ventilatory oscillation was determined as the ratio between amplitude and mean of each oscillation during incremental exercise. Patients with IMW had greater peripheral chemoreflex response (0.11+/-0.03 l min(-1) Torr(-1)) than those with preserved inspiratory muscle strength (0.07+/-0.03 l min(-1) Torr(-1), p=0.02). Moreover, there was a significant and inverse correlation between PImax and peripheral chemoreflex response (r=-0.57, p=0.01). Likewise, there was a significant and inverse correlation between PImax and ventilatory oscillations (r=-0.46, p=0.04). Our findings indicate that IMW is linked to increased peripheral chemoreflex and augmented exercise ventilatory oscillation in patients with chronic heart failure.

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Background Maximal inspiratory pressure (PI max ) and 6-minutes walk distance test (6MWD) may be more available and feasible alternatives for prognostic assessment than cardiopulmonary testing. We hypothesized that the PI max and 6MWD combination could improve their individual accuracy as risk predictors. We aimed to evaluate PI max ability as a mortality predictor in HF and whether the combination to 6MWD could improve risk stratification. Methods Prospective cohort from HF Clinics of three University Hospitals. PI max , 6MWD and pVO 2 were obtained at baseline. The end point was all cause mortality. Results Consecutive 256 individuals (50% woman, 57.4±10.4years) with low ejection fraction (LVEF) (31.8±8.6%) were followed up to 10years. During a median follow-up of 34.7 (IQR 37) months, 110 participants died. Mean±SD values were: pVO 2 14.9±5.1mL/kg/min, PI max 5.5±1.3kPa and 6MWD 372±118m. In multivariate Cox regression, pVO 2 , PI max , 6MWD and LVEF were independent mortality predictors. The pVO 2 showed gold standard accuracy, followed by PI max (AUC = 0.84) and 6MWD (AUC = 0.74). Kaplan-Meier mean survival time (MST±SE) for lower (≤5.0kPa) and higher (>6.0kPa) PI max tertiles, were 37.9±2.8months and 105.0±5.2months respectively, and addition of 6MWD did not restratified risk. For intermediate PI max tertile, MST was 81.5±5.5months, but adding 6MWD, MST was lower (53.3±7.6months) if distance was ≤350m and higher (103.1±5.7months) for longer distances. Conclusion PI max is an independent mortality predictor in HF, more accurate than 6MWD and LVEF. Addition of 6MWD empowers risk stratification only for intermediate PI max tertile. Although less accurate than pVO 2 , this simpler approach could be a feasible alternative as a prognostic assessment.

Introdução: A depressão compreende alterações cognitivas, de humor, psicomotoras e vegetativas. Objetivo: Analisar atividades desenvolvidas por mulheres com diagnóstico de depressão, assistidas em um Centro de Atenção Psicossocial-CAPS da Região Noroeste do Estado do Rio Grande do Sul, com base nos planos terapêuticos instituídos pela equipe multipro ssional. Metodologia: quantitativa, documental. Projeto aprovado por Comitê de Ética, Parecer 033/2012. Coletado dados de 196 mulheres: idade, estado civil, tempo de tratamento, internação hospitalar, primeiros sintomas, atividades, plano terapêutico. Análise dos dados com estatística descritiva. Resultados: 51,6%, 40-60 anos, casadas, 48,3% em tratamento de 1-5 anos, 67,3% nunca internaram, primeiros sintomas 30-50 anos de idade. Mulheres participam de atividades com psicólogo, assistente social, enfermeiro, artesanato e música; 81,7% duas a três atividades, nas modalidades semi e não intensivo. Conclusão: estudos do per l sociodemográ co de pacientes com depressão são importantes para quali car a assistência e como subsídios na construção de políticas públicas.