, Volume 16, Issue 3, pp 593-594
Date: 26 Jun 2011

Heart rate recovery in obstructive sleep apnea: scientific toy or clinical tool?

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Autonomic dysfunction is a hallmark of the obstructive sleep apnea syndrome (OSA). Intermittent hypoxia and sleep fragmentation are thought to represent the key mechanisms promoting sympathetic overactivity and blunted vagal tone even during wakefulness in OSA. Muscle sympathetic activity (MSNA) is increased in OSA compared to controls [1] and treatment with continuous positive airway pressure (CPAP) can reverse this [2]. However, the measurement of MSNA is a demanding technique. In recent years, a simpler measure of autonomic tone has become very popular in a variety of settings including OSA: heart rate recovery (HRR), which simply measures how quickly heart rate is reduced after exercise. The seminal study by Cole et al. [3] promoting an intense interest in HRR showed that among subjects undergoing a maximal treadmill test for the evaluation of possible coronary artery disease, those with a reduction in heart rate within the first minute after exercise termination (HRR-1) of 12 beat