The Impact of Volume Overload on Obstructive Sleep Apnea in Patients With Congestive Heart Failure

The goal of this observational study is to learn how removing extra fluid from the body (diuresis) affects sleep apnea in adults hospitalized with heart failure. The main questions it aims to answer are: Does sleep apnea severity improve after fluid removal? Is the improvement in sleep apnea related to the amount of fluid removed? Do changes in neck size reflect changes in sleep apnea severity? Participants admitted to the hospital with heart failure and fluid overload will take part in this study. Participants will: Use a wearable sleep monitoring device (WatchPAT) on the first night of hospitalization Use the device again after fluid removal, when the treating cardiologist determines that the patient is no longer fluid overloaded Have their neck circumference measured before and after fluid removal Have their weight and fluid balance recorded during hospitalization Have routine blood tests and clinical assessments as part of standard care Researchers will compare each participant's results before and after fluid removal to see if sleep apnea improves and whether these changes are linked to fluid removal and changes in neck circumference.