ResumoA queda em idosos é resultado de uma interação complexa entre fatores intrínsecos e extrínsecos. Embora seja difícil separar esses fatores, estudos apontam que fatores de risco ambientais estão presentes em aproximadamente 40% das quedas. O objetivo deste estudo foi realizar uma revisão sistemática da literatura sobre o envolvimento de fatores ambientais nas quedas em idosos vivendo na comunidade. Para tanto, foram selecionados estudos publicados no período de janeiro de 2000 a maio de 2014 nas bases de dados eletrônicas MEDLINE, LILACS e SciELO. Apenas artigos disponíveis na íntegra e em inglês, português e espanhol foram considerados para esta revisão. Após a análise do título, do resumo e do texto na íntegra, dez artigos foram incluídos na revisão. Nos estudos analisados, aproximadamente metade das quedas ocorreu durante a locomoção e envolveu tropeços e escorregões. Os fatores de risco ambientais estão muito presentes nas quedas (20-58%), sendo que superfícies irregulares, superfícies molhadas/escorregadias, objetos/tapetes soltos e desníveis no chão/problemas com degraus foram os mais prevalentes. Observou-se tendência de aumento na ocorrência de quedas em ambientes externos, as quais são frequentemente precipitadas por fatores extrínsecos. Mais estudos são necessários na caracterização e no desenvolvimento de estratégias de prevenção de quedas em ambientes externos. AbstractFalls in the elderly is the result of a complex interplay between intrinsic and extrinsic factors. Although it is difficult to separate these factors, studies indicate that environmental hazards are involved in approximately 40% of the falls. This study aimed to conduct a systematic review about the contribution of environmental hazards for falls in community-dwelling elderly. Studies published from January 2000 to May 2014 in the electronic databases MEDLINE, LILACS and SciELO were selected. Only free full-text articles written in English, Portuguese and Spanish were considered Palavras-chave: Acidentes por Quedas. Idoso. Medicina Ambiental.http://dx

Heart failure (HF) is characterized by decreased exercise capacity, attributable to neurocirculatory and skeletal muscle factors. Cardiac resynchronization therapy (CRT) and exercise training have each been shown to decrease muscle sympathetic nerve activity (MSNA) and increase exercise capacity in patients with HF. We hypothesized that exercise training in the setting of CRT would further reduce MSNA and vasoconstriction and would increase Ca-handling gene expression in skeletal muscle in patients with chronic systolic HF. Thirty patients with HF, ejection fraction <35% and CRT for 1 mo, were randomized into two groups: exercise-trained (ET, n = 14) and untrained (NoET, n = 16) groups. The following parameters were compared at baseline and after 4 mo in each group: V̇o, MSNA (microneurography), forearm blood flow, and Ca-handling gene expression in vastus lateralis muscle. After 4 mo, exercise duration and V̇o were significantly increased in the ET group (P = 0.04 and P = 0.01, respectively), but not in the NoET group. MSNA was significantly reduced in the ET (P = 0.001), but not in NoET, group. Similarly, forearm vascular conductance significantly increased in the ET (P = 0.0004), but not in the NoET, group. The expression of the Na/Ca exchanger (P = 0.01) was increased, and ryanodine receptor expression was preserved in ET compared with NoET. In conclusion, the exercise training in the setting of CRT improves exercise tolerance and neurovascular control and alters Ca-handling gene expression in the skeletal muscle of patients with systolic HF. These findings highlight the importance of including exercise training in the treatment of patients with HF even following CRT.

The objective of this study was to evaluate cardiac autonomic control and muscle vasodilation response during isometric exercise in sedentary and physically active older adults. Twenty healthy participants, 10 sedentary and 10 physically active older adults, were evaluated and paired by gender, age, and body mass index. Sympathetic and parasympathetic cardiac activity (spectral and symbolic heart rate analysis) and muscle blood flow (venous occlusion plethysmography) were measured for 10 minutes at rest (baseline) and during 3 minutes of isometric handgrip exercise at 30% of the maximum voluntary contraction (sympathetic excitatory maneuver). Variables were analyzed at baseline and during 3 minutes of isometric exercise. Cardiac autonomic parameters were analyzed by Wilcoxon and Mann–Whitney tests. Muscle vasodilatory response was analyzed by repeated-measures analysis of variance followed by Tukey’s post hoc test. Sedentary older adults had higher cardiac sympathetic activity compared to physically active older adult subjects at baseline (63.13±3.31 vs 50.45±3.55 nu, P=0.02). The variance (heart rate variability index) was increased in active older adults (1,438.64±448.90 vs 1,402.92±385.14 ms, P=0.02), and cardiac sympathetic activity (symbolic analysis) was increased in sedentary older adults (5,660.91±1,626.72 vs 4,381.35±1,852.87, P=0.03) during isometric handgrip exercise. Sedentary older adults showed higher cardiac sympathetic activity (spectral analysis) (71.29±4.40 vs 58.30±3.50 nu, P=0.03) and lower parasympathetic modulation (28.79±4.37 vs 41.77±3.47 nu, P=0.03) compared to physically active older adult subjects during isometric handgrip exercise. Regarding muscle vasodilation response, there was an increase in the skeletal muscle blood flow in the second (4.1±0.5 vs 3.7±0.4 mL/min per 100 mL, P=0.01) and third minute (4.4±0.4 vs 3.9±0.3 mL/min per 100 mL, P=0.03) of handgrip exercise in active older adults. The results indicate that regular physical activity improves neurovascular control of muscle blood flow and cardiac autonomic response during isometric handgrip exercise in healthy older adult subjects.

No abstract