In this issue of CHEST (see page 927), Zhang and colleagues10 evaluated a novel method of treating CSA-CSR in patients with heart failure through the use of transvenous phrenic nerve stimulation (PNS). Patients with implantable devices (ie, pacemaker, defibrillator, resynchronization device) were excluded. The objective of the authors was to stimulate the diaphragm, thereby preventing central apnea and the associated hyperpnea phase. Sixteen patients underwent successful stimulation capture of the phrenic nerve during a single overnight sleep study (19 enrolled, three failed to capture). The subjects served as their own controls (prestimulation period). Compared with controls, there was a significant decrease in the apnea-hypopnea index (AHI) (33.8±9.3 vs 8.1±2.3; normal, <5; mild, 5-15; moderate, 16-30; severe, >30/h sleep). The study also showed improvements in the oxygen desaturation index (ODI) and increases in mean and minimal oxyhemoglobin saturation. Ventilatory parameters improved, with an increase in Paco2 and a corresponding decrease in respiratory rate. Of note, the AHI remained mildly elevated (8.2±2.3) during treatment. Neither cardiac arrhythmias nor hemodynamic instability were observed during this single night.