Caruso Flavia Cristina Rossi, Simões Rodrigo Polaquini, Reis Michel Silva, Guizilini Solange, Alves Vera Lucia dos Santos, Papa Valeria, Arena Ross, Borghi-Silva Audrey
Laboratory of Cardiopulmonary Physiotherapy, Federal University of São Carlos, São Carlos, SP, Brazil.
Department of Physiotherapy, Faculty of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Braz J Cardiovasc Surg. 2016 Feb;31(1):38-44. doi: 10.5935/1678-9741.20160007.
To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting.
Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values.
Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P <0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P <0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition.
These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.
评估曾接受冠状动脉搭桥术的患者在三种不同负荷水平[最大吸气压力的30%、60%和80%]的吸气肌耐力训练方案期间的心率变异性。
对19名参与心血管康复计划的冠状动脉搭桥术后晚期患者进行了研究。进行了最大吸气压力测试。以随机顺序分别应用最大吸气压力的30%、60%和80%的吸气肌耐力训练方案，每次持续4分钟。记录心率和RR间期，并通过时间域指标（RMSSD - 所有RR间期标准差的平均值，以及RMSM - 连续RR间期的均方根差）和频率域指标（高频和低频）以标准化单位分析心率变异性。使用重复测量方差分析比较心率变异性指标，使用学生t检验比较最大吸气压力和最大呼气压力值。
在进行最大呼吸压力测试期间心率增加，最大吸气压力和最大呼气压力平均值显著低于预测值（P<0.05）。与休息时和最大吸气压力的30%相比，RMSSD在最大吸气压力的80%时显著增加，而与休息时相比，RMSM在最大吸气压力的30%和60%时降低（P<0.05）。此外，与静息状态相比，在最大吸气压力的30%、60%和80%时，低频显著且逐渐降低，高频增加。
这些结果表明，高强度呼吸肌训练可促进更大的副交感神经活动，并且在冠状动脉搭桥术后的康复计划中可能带来重要益处。
