1. What is heart failure?
Blood contains oxygen and nutrients which is needed by the various tissues and organs of the body. The heart is the organ which pumps the blood to the different parts of the body so as to distribute the oxygen and nutrients. Heart failure is when the heart is unable to pump enough blood to meet the body's requiremnets. When the heart begins to fail, it compensates by trying to pump faster and harder so as to continue to meet the requirements of the body. However, over time, the heart is not able to compensate enough and can no longer meet the needs of the body. This is when the symptoms of heart failure start to show.
2. What are the causes of heart failure?
There are many causes of heart failure. Basically, anything that results in damage to the heart can result in heart failure. The more common causes of heart failure are listed below, as well as other factors that can increase your risk of having heart failure.
Heart attack (Myocardial Infarction)
A heart attack happens when the arteries supplying the heart are block and the heart muscles are not able to recieve oxygen. This causes the heart muscles to die and damages the heart, making it unable to pump as effectively as before.
Coronary Artery Disease
Cholesterol and fatty deposits block up the arteries supplying the heart, which can result in a heart attack. The muscles of the heart get less oxygen and nutrients and eventually die, leaving the remaning muscles of the heart to have to work harder.
High Blood Pressure (Hypertension)
The heart has to pump against a higher pressure than usual. More energy and oxygen is required to do this, and if the arteries to the heart are not able to supply this extra oxygen the heart gets damage and is even more unable to cope with the higher pressure.
One of the complications of diabetes is damage to the blood vessel walls, including the arteries that supply the heart. Diabetes is also associated with high blood pressure and high cholesterol, both of which as contribute to heart failure.
Abnormal Heart Valves
This could be either be from birth or acquired (from a previous heart attack or rheumatic heart disease). Due to the abnormal valves the heart becomes an ineffective pump and has to work harder therefore resulting in alot of strain on the heart.
Heart Muscle Disease (Cardiomyopathies, Myocarditis)
Drugs, alcohol and some medications and hereditary condtions can cause the heart muscles to become inflammed and damage and thus resulting in heart failure.
Lung Disease (Cor Pumonale)
Severe lung disease results in poor oxygenation of the blood. The heart has to pump harder to get more lowly oxygenated blood to meet the body's requirements.
3. What are the symptoms of heart failure?
Some of the more common symptoms of heart failure include:
- Shortness of breath at rest, during light exercise of when lying down
- Feeling tired (fatigue)
- Cough at night
- Swelling of the feet and calves
- Swelling of the abdomen
- The above list of symptoms is not exhaustive.
4. How is heart failure treated?
The most important thing is to treat the underlying cause of the heart failure, if it is known, and also to avoid habits that will increase the risk of heart failure. For example, if the cause of the heart failure is diabetes, both the diabetes and the heart failure must be treated appropriately. Lifestyle modifications such as to stop smoking and eating less salt should also be encouraged. The doctor may also prescribe you some medication to help treat your heart failure, some of these are described below.
Diuretics make you produce more urine, and thus reduces the volume of the blood. This would result in a decrease in the blood pressure. With a lower blood pressure the heart does not need to pump as hard and therefore would have time to slowly recover. Diuretics also remove the fluid collected in the lungs, the legs and abdomen, thus helping to relieve some of the symptoms of heart failure.
ACE-inhibitors work by blocking an enzyme known as Angiotensin Converting Enzyme (ACE). ACE is responsible for the production of a protein called Angiotensin II. Angiotensin causes blood vessels to constrict which results in the rise of blood pressure. It also triggers the production of the hormone Aldosterone, which causes the body to retain salt and water and therefore rising the blood pressure as well. By blocking the action of ACE, the blood pressure is lowered and the body does not retain as much salt and water, thus helping lessen the strain on the heart and relieving some of the symptoms of heart failure.
Beta-blockers block the action of catecholamines (one of which is adrenaline / epinephrine). This slows down the rate of the heart as well as decreases the strength at which the heart pumps. This allows the heart to rest and slowly recover.
Digoxin works by making the heart pump faster and harder, thus enabling it to meet the requirements of the body and helping to relieve some of the symptoms of heart failure.
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