Immediate effects of arousal from sleep on cardiac autonomic outflow in the absence of breathing in dogs

To determine the immediate effects of arousal from non-rapid-eye-movement (non-REM) sleep on cardiac sympathetic and parasympathetic activities, six dogs were studied breathing through an endotracheal tube inserted into a chronic tracheostomy. Mean heart rates (HRs) during non-REM sleep were compared with 1) awake periods immediately after spontaneous arousals (ARs) and 2) later periods of stable relaxed wakefulness (RW). During spontaneous …