The work by Mansfield and colleagues also raises some important questions. First, in their article, the authors do not distinguish CSA from CSR. In both pretransplant and posttransplant settings, central apneas were labeled as CSA with CSR, although, clearly, the appearances of these events in the two settings differed markedly (Fig 2). Admittedly, there is no universally accepted definition of CSR or CSA, and the distinction is not always clear. However, they provide different clinical and prognostic information. Classic CSR usually occurs in patients with CHF or stroke and is, as mentioned previously, associated with a bad prognosis. However, idiopathic CSA is observed in those without any comorbidities and is not necessarily periodic in nature. Moreover, there are no data indicating that the presence of idiopathic or postarousal CSA by itself is a poor prognostic marker for patients, and no consensus on when and how it should be treated. In view of these differences, there is a definite need to develop a more precise definition of CSR-CSA to better define the relevance of CSR-CSA in CHF, and to foster comparisons of data across studies. We believe that studies examining CSR-CSA should, as a minimum, report on the cycle length, magnitude of oxyhemoglobin desaturation, the timing of arousals relative to the respiratory events, and frequency and duration of apneas and hypopneas of their study patients to distinguish classic CSR-CSA from idiopathic CSA.