Nobre T S, Groehs R V, Azevedo L F, Antunes-Correa L M, Martinez D G, Alves M J N N, Negrao C E
Heart Institute (InCor), Medical School of University of Sao Paulo, Cardiovascular Rehabilitation and Exercise Physiology Unit, Sao Paulo, Brazil.
Unit of Cardiovascular Investigation and Exercise Physiology,Faculty of Physical Education, Federal University of Juiz de Fora, Minas Gerais, Brazil.
Int J Sports Med. 2016 Dec;37(13):1073-1079. doi: 10.1055/s-0042-114701. Epub 2016 Sep 27.
It remains unknown whether or not a reduction in muscle sympathetic nerve activity in heart failure patients is associated over time with the effects of long- or short-term repeated exercise. 10 chronic heart failure patients, age 49±3 years old, functional class I-III NYHA, ejection fraction <40% were randomly submitted to either an acute bout of moderate continuous exercise OR high-intensity interval exercise. Muscle sympathetic nerve activity (microneurography) and forearm blood flow (venous occlusion plethysmography) were evaluated pre- and post-exercise sessions. The moderate exercise consisted of cycle exercise at an intensity corresponding to anaerobic threshold. The interval exercise consisted of a 2-min cycle exercise at intensity corresponding to anaerobic threshold, followed by a 1-min exercise set at respiratory compensation point. Exercise capacity was evaluated by cardiopulmonary exercise test. The caloric expenditure in both sessions was 100 kcal. Baseline muscle sympathetic nerve activity and forearm blood flow levels were not different between sessions. Moderate or high-intensity exercise caused no significant changes in muscle sympathetic nerve activity and forearm blood flow. These findings suggest that the reduction in muscle sympathetic nerve activity and the increase in forearm blood flow provoked by exercise training in chronic heart failure patients are due to cumulative effects over time.
心力衰竭患者肌肉交感神经活动的降低是否会随着时间的推移与长期或短期重复运动的效果相关，目前尚不清楚。10名年龄在49±3岁、纽约心脏协会心功能分级为I-III级、射血分数<40%的慢性心力衰竭患者被随机分为两组，分别进行一次急性中度持续运动或高强度间歇运动。在运动前后评估肌肉交感神经活动（微神经电图）和前臂血流量（静脉阻塞体积描记法）。中度运动包括以对应无氧阈值的强度进行自行车运动。间歇运动包括以对应无氧阈值的强度进行2分钟自行车运动，然后以呼吸补偿点的强度进行1分钟运动组。通过心肺运动试验评估运动能力。两个运动时段的热量消耗均为100千卡。两个运动时段的基线肌肉交感神经活动和前臂血流量水平没有差异。中度或高强度运动对肌肉交感神经活动和前臂血流量没有显著影响。这些发现表明，慢性心力衰竭患者运动训练引起的肌肉交感神经活动降低和前臂血流量增加是由于随着时间的累积效应。
