FIG. 6:  In contrast to the previous Figures, which depicted OSA in heart failure, this Figure shows tracings from a patient with heart failure and CSA.  Here the characteristic feature is an apnea with no movement of the rib cage or abdomen, and esophageal pressure with no esophageal pressure swings. 

Toward the right side of the Figure the patient starts to breathe again, there is a crescendo pattern of ventilation, and the esophageal pressure becomes negative.  Since esophageal pressure is the driving pressure for breathing, oxygen saturation (SaO₂) falls as a result of that apnea.

So the difference between heart failure with OSA vs CSA is that during CSA there is no respiratory effort, whereas during OSA there is a huge decrease in intrathoracic pressure due to the respiratory effort.