Department of Mechanical Engineering, University College London London, UK.
Front Physiol. 2012 Sep 24;3:379. doi: 10.3389/fphys.2012.00379. eCollection 2012.
Respiratory modulation of autonomic input to the sinus node results in cyclical modulation of heart rate, known as respiratory sinus arrhythmia (RSA). We hypothesized that the respiratory cycle may also exert cyclical modulation on ventricular repolarization, which may be separately measurable using local endocardial recordings.
The study included 16 subjects with normal ventricles undergoing routine clinical electrophysiological procedures for supraventricular arrhythmias. Unipolar electrograms were recorded from 10 right and 10 left ventricular endocardial sites. Breathing was voluntarily regulated at 5 fixed frequencies (6, 9, 12, 15, and 30 breaths per min) and heart rate was clamped by RV pacing. Activation-recovery intervals (ARI: a surrogate for APD) exhibited significant (p < 0.025) cyclical variation at the respiratory frequency in all subjects; ARI shortened with inspiration and lengthened with expiration. Peak-to-peak ARI variation ranged from 0-26 ms; the spatial pattern varied with subject. Arterial blood pressure also oscillated at the respiratory frequency (p < 0.025) and lagged behind respiration by between 1.5 s and 0.65 s from slowest to fastest breathing rates respectively. Systolic oscillation amplitude was significantly greater than diastolic (14 ± 5 vs. 8 ± 4 mm Hg ± SD, p < 0.001).
Observations in humans with healthy ventricles using multiple left and right ventricular endocardial recordings showed that ARI action potential duration (APD) varied cyclically with respiration.
呼吸对窦房结自主传入的调节导致心率的周期性变化，称为呼吸窦性心律失常（RSA）。我们假设呼吸周期也可能对心室复极施加周期性调节，这可以使用局部心内膜记录分别测量。
该研究纳入了 16 名心室正常的患者，他们因室上性心律失常而接受常规临床电生理程序。从 10 个右心室和 10 个左心室心内膜部位记录单极电图。呼吸在 5 个固定频率（6、9、12、15 和 30 次/分钟）下进行自主调节，心率通过 RV 起搏固定。在所有患者中，激活恢复间期（ARI：APD 的替代指标）在呼吸频率下均表现出显著（p < 0.025）的周期性变化；ARI 在吸气时缩短，呼气时延长。峰峰值 ARI 变化范围为 0-26 ms；空间模式随患者而变化。动脉血压也以呼吸频率波动（p < 0.025），从最慢到最快呼吸频率，分别滞后呼吸 1.5 秒至 0.65 秒。收缩期波动幅度明显大于舒张期（14 ± 5 对 8 ± 4 毫米汞柱 ± 标准差，p < 0.001）。
在使用多个左心室和右心室心内膜记录的健康心室的人类中观察到，ARI 动作电位持续时间（APD）随呼吸周期性变化。
