Adams Jenny, Julian Peter, Hubbard Matthew, Hartman Julie, Baugh Sally, Segrest Wendy, Russell Jenny, McDonnell Jeff, Wheelan Kevin
Baylor Jack and Jane Hamilton Heart and Vascular Hospital, 411N. Washington Suite 3100, Dallas, TX 75246, USA.
Clin Rehabil. 2009 Sep;23(9):782-9. doi: 10.1177/0269215509334834. Epub 2009 Jun 8.
To determine whether a controlled breathing programme increases heart rate variability following an acute myocardial infarction and/or coronary artery bypass graft surgery.
Heart rate variability is reduced following a myocardial infarction, and low heart rate variability is associated with a high mortality risk. By changing tidal volume and rate of breathing, individuals can alter beat-to-beat heart rate variability. It is hypothesized that heart rate increases with inspiration and decreases with exhalation, and that deep slow breathing enhances respiratory sinus arrhythmia, increasing heart rate variability.
Randomized controlled trial.
Cardiac rehabilitation programme at a large academic medical centre in North Texas.
From 2001 to 2005, 44 patients, age 46-65 years, who had a myocardial infarction and/or undergone coronary artery bypass graft surgery 1-8 weeks previously and were referred to the Cardiac Rehabilitation Program.
Patients were randomized to either usual cardiac rehabilitation or cardiac rehabilitation with controlled breathing (6 breaths/min for 10 minutes twice daily during the eight-week treatment period).
Weekly measurements of total power and standard deviation of the mean normal to normal RR interval (SDNN), and fortnightly measurements of respiratory sinus arrhythmia were taken using Biocom Technologies Heart Rhythm Scanner and Tracker software.
No significant difference in change were seen between groups in SDNN (P = 0.3984), baseline respiratory sinus arrhythmia (P = 0.6556) or total power (P = 0.6184).
Results suggest participation in the controlled breathing programme offered no additional benefit in increasing heart rate variability following myocardial infarction or coronary artery bypass graft surgery. However, 77% of study patients were on heart rate-lowering medications, which may have masked changes in heart rate variability.
确定一项控制呼吸方案是否能增加急性心肌梗死和/或冠状动脉搭桥手术后的心率变异性。
心肌梗死后心率变异性降低，而低心率变异性与高死亡风险相关。通过改变潮气量和呼吸频率，个体可以改变逐搏心率变异性。据推测，心率在吸气时增加，呼气时降低，深度慢呼吸可增强呼吸性窦性心律不齐，增加心率变异性。
随机对照试验。
北德克萨斯州一家大型学术医疗中心的心脏康复项目。
2001年至2005年期间，44名年龄在46 - 65岁之间的患者，他们在1 - 8周前发生过心肌梗死和/或接受了冠状动脉搭桥手术，并被转诊至心脏康复项目。
患者被随机分为接受常规心脏康复治疗或接受控制呼吸的心脏康复治疗（在为期八周的治疗期间，每天两次，每次10分钟，呼吸频率为每分钟6次）。
使用Biocom Technologies公司的心律扫描仪和追踪软件，每周测量正常到正常RR间期的总功率和标准差（SDNN），每两周测量呼吸性窦性心律不齐。
两组在SDNN（P = 0.3984）、基线呼吸性窦性心律不齐（P = 0.6556）或总功率（P = 0.6184）的变化上没有显著差异。
结果表明，参与控制呼吸方案对增加心肌梗死或冠状动脉搭桥手术后的心率变异性没有额外益处。然而，77%的研究患者正在服用降低心率的药物，这可能掩盖了心率变异性的变化。
