While the functional deficit of the heart muscle is the underlying cause of the patient's disease and is a strong predictor of mortality, congestive symptoms are more closely associated with quality of life.
Congestive symptoms are only weakly related to the severity of heart failure.
It often happens that a patient with a seriously compromised ejection fraction may be maintained relatively symptom-free, while another patient with mild LVD experiences frequent congestive symptoms. It is therefore important to treat LVD and congestion separately.