congestive heart failure is generally a progressive disease with periods of stability punctuated by episodic clinical exacerbations. the course of the disease in any given individual however is extremely variable. factors involved in determining the long term outlook (prognosis) for a given patient include: the nature of the underlying heart disease the response to medications the degree to which other organ systems are involved and the severity of other accompanying conditions the person's symptoms and degree of impairment other factors that remain poorly understood with the availability of newer drugs to potentially favorably affect the progression of disease the prognosis in congestive heart failure is generally more favorable than that observed just 10 years ago. in some cases especially when the heart muscle dysfunction has recently developed a significant spontaneous improvement is not uncommonly observed even to the point where heart function becomes normal. heart failure is often graded on a scale of i to iv based on the patient's ability to function. class i is patients with a weakened heart but without limitation or symptoms. class ii is only limitation at heavier workloads. class iii is limitation at everyday activity. class iv is severe symptoms at rest or with any degree of effort. the prognosis of heart failure patients is very closely associated with the functional class. an important issue in congestive heart failure is the risk of heart rhythm disturbances (arrhythmias). of those deaths that occur in individuals with congestive heart failure approximately 50% are related to progressive heart failure. importantly the other half are thought to be related to serious arrhythmias. a major advance has been the finding that nonsurgical placement of automatic implantable cardioverter/defibrillators (aicd) in individuals with severe congestive heart failure (defined by an ejection fraction below 30%-35%) can significantly improve survival and has become the standard of care in most such individuals. in some people with severe heart failure and certain ecg abnormalities the left and right side of the heart don't beat in rhythm and inserting a device called a biventricular pacer can significantly reduce symptoms.
what is the long-term outlook for patients with congestive heart failure?