So how can the study of Brack et al1 promote the field? First, it has highlighted the circadian pattern of CSR and leaves open the following questions: is CSR circadian, exercise related, postural, or related to the medical therapies? Second, this study and others7 indicate that we should consider the prognostic importance of periodic breathing during wakefulness or exercise, especially as exercise testing is a commonly used tool by cardiologists to decide on transplantation suitability and prognosis. Third, it opens the field to promote alternative and longer diagnostic strategies: these might include actigraphy, heart rate variability, highly sensitive oximetry, or all of the above. Finally, should one consider expanding the metric of CSR beyond the apnea-hypopnea index to include cycle length, duration of periodic breathing (or CSR as a percentage of the night), and CSR during wakefulness, all of which can be determined from polysomnography?