Friday, August 19, 2011

ABOUT HEART FAILURE

Everyone likes to think that they will live to a ripe old age and be active and healthy all the while. But many patients have been told that they have 'heart failure'. This is a frightening prognosis at best. We have to ask ourselves exactly what does heart failure really mean?

 Heart failure (HF) is generally defined as inability of the heart to supply sufficient blood flow to meet the body's needs. It has various diagnostic criteria, and the term heart failure is often incorrectly used to describe other cardiac-related illnesses, such as myocardial infarction (heart attack) or cardiac arrest.

Common causes of heart failure include:
<> myocardial infarction
<> ischemic heart disease
<> hypertension
<> valvular heart disease
<> cardiomyopathy.

Heart failure can cause a number of symptoms including shortness of breath, typically worse when lying flat, (which is called orthopnea), coughing, chronic venous congestion, ankle swelling, and exercise intolerance. Heart failure is often undiagnosed because of a lack of a universally agreed definition and challenges in definitive diagnosis. Treatment commonly consists of changes in lifestyle such as smoking cessation, light exercise including breathing protocols, decreased salt intake and other dietary measures and medications. Sometimes devices or even surgery become necessary.

Heart failure is a common, costly, disabling, and potentially deadly condition. In developed countries, apprx 20% of adults suffer from heart failure, but in those over the age of 65, this increases by 6–10%. Mostly as a result of the costs of hospitalization, it is associated with a high health expenditure; costs have been estimated to amount to 2% of the total budget of the National Health Service in the United Kingdom, and more than $35 billion in the United States. Heart failure is associated with significantly reduced physical and mental health, resulting in a markedly decreased quality of life. With the exception of heart failure caused by reversible conditions, the condition usually worsens with time. Although some people survive many years, progressive disease is associated with an overall annual mortality rate of 10%.

Heart failure is a global term for the physiological state in which cardiac output is insufficient in meeting the needs of the body and lungs. Often termed "congestive heart failure" or CHF, this is most commonly caused when cardiac output is low and the body becomes congested with fluid. (Fluid is not necessarily near the heart; it is often found  in the lower extremities.) It may also occur when the body's requirements for oxygen and nutrients are increased and the demand outstrips what the heart can provide. This can occur from severe anemia, Gram negative septicaemia, vitamin B1/thiamine deficiency (beriberi), hyperthyroidism, Paget's disease, arteriovenous fistulae, or arteriovenous malformations. Fluid overload is a common problem for people with heart failure. This is termed "high output cardiac failure" but is not synonymous with it. Patients with treated heart failure will often be euvolaemic (a term for normal fluid status), or more rarely, dehydrated. Medical professionals use the words "acute" to mean of rapid onset and "chronic" to mean of long duration.

 Chronic heart failure is therefore a long term situation, usually with stable treated symptomatology. Acute decompensated heart failure is a term used to describe exacerbated or decompensated heart failure, referring to episodes in which a patient can be characterized as having a change in heart failure signs and symptoms resulting in a need for urgent therapy or hospitalization. There are several terms which are closely related to heart failure, and may be the cause of heart failure, but should not be confused with it:

a. Cardiac arrest and asystole refer to situations in which there is no cardiac output at all. Without urgent treatment these result in sudden death.

b. Myocardial infarcation ("Heart attack") refers to heart muscle damage due to insufficient blood supply, usually as a result of a blocked coronary artery. 

c. Cardiomyopathy refers specifically to problems within the heart muscle, and these problems usually result in heart failure. 

d.Ischemic cardiomyopathy implies that the cause of muscle damage is coronary artery disease.

e. Dilated cardiomyopathy implies that the muscle damage has resulted in enlargement of the heart.

f. Hypertrophic cardiomyopathy involves enlargement and thickening of the heart muscle.