Shortness of breath
Shortness of breath in the CHF patient is due to elevated pulmonary artery pressures.
Pulmonary artery pressures are more elevated in the supine position as compared to the seated or upright positions. In a patient who is adequately treated, the supine position is not a problem. In a patient who is inadequately treated (decompensated), the supine position will make shortness of breath worse.