vitamin for the heart

Ellen Says: Heart failure is a global term for the physiological state in which cardiac output is insufficient for the body's needs.

This occurs most commonly when the cardiac output is low (often termed "congestive heart failure" because the body becomes congested with fluid).

In contrast, it may also occur when the body's requirements for oxygen and nutrients are increased, and demand outstrips what the heart can provide, (termed "high output cardiac failure"). This can occur in the context of severe anemia, Gram negative septicaemia, beriberi (vitamin B1/thiamine deficiency), thyrotoxicosis, Paget's disease, arteriovenous fistulae or arteriovenous malformations.

Fluid overload is a common problem for people with heart 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.

Doctors use the words "acute" to mean of rapid onset, and "chronic" 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:

* Cardiac arrest, and asystole both refer to situations in which there is no cardiac output at all. Without urgent treatment, these result in sudden death.
* Myocardial infarction ("Heart attack") refers heart muscle damage due to insufficient blood supply, usually as a result of a blocked coronary artery.
* Cardiomyopathy refers specifically to problems within the heart muscle, and these problems usually result in heart failure. Ischemic cardiomyopathy implies that the cause of muscle damage is coronary artery disease. Dilated cardiomyopathy implies that the muscle damage has resulted in enlargement of the heart. Hypertrophic cardiomyopathy involves enlargement and thickening of the heart muscle.


Gbex says: There are many different ways to categorize heart failure, including:

* the side of the heart involved, (left heart failure versus right heart failure)
* whether the abnormality is due to contraction or relaxation of the heart (systolic dysfunction vs. diastolic dysfunction)
* whether the problem is primarily increased venous back pressure (behind) the heart, or failure to supply adequate arterial perfusion (in front of) the heart (backward vs. forward failure)
* whether the abnormality is due to low cardiac output with high systemic vascular resistance or high cardiac output with low vascular resistance (low-output heart failure vs. high-output heart failure)
* the degree of functional impairment conferred by the abnormality (as in the NYHA functional classification)

Functional classification generally relies on the New York Heart Association Functional Classification. The classes (I-IV) are:

* Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.
* Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.
* Class III: marked limitation of any activity; the patient is comfortable only at rest.
* Class IV: any physical activity brings on discomfort and symptoms occur at rest.


Lawrence says: The predominance of causes of heart failure are difficult to analyze due to challenges in diagnosis, differences in populations, and changing prevalence of causes with age.

A 19 year study of 13000 healthy adults in the United States (the National Health and Nutrition Examination Survey (NHANES I) found the following causes ranked by Population Attributable Risk score:

1. Ischaemic heart disease 62%
2. Cigarette smoking 16%
3. Hypertension (high blood pressure)10%
4. Obesity 8%
5. Diabetes 3%
6. Valvular heart disease 2% (much higher in older populations)

An Italian registry of over 6200 patients with heart failure showed the following underlying causes:

1. Ischaemic heart disease 40%
2. Dilated cardiomyopathy 32%
3. Valvular heart disease 12%
4. Hypertension 11%
5. Other 5%

Rarer causes of heart failure include:

* Viral myocarditis (an infection of the heart muscle)
* Infiltrations of the muscle such as amyloidosis
* HIV cardiomyopathy (caused by human immunodeficiency virus)
* Connective tissue diseases such as systemic lupus erythematosus
* Abuse of drugs such as alcohol and cocaine
* Pharmaceutical drugs such as chemotherapeutic agents
* Arrhythmias

Obstructive sleep apnea a condition of sleep disordered breathing overlaps with obesity, hypertension and diabetes and is regarded as an independent cause of heart failure.