Feb 2008 Newsletter
Special Focus: Heart
The heart pumps 2.5 billions times in an average lifetime moving about 8 tonnes of blood in a day. When this process does not work properly, serious illness and even death can result. In case of an adverse event it is important to find quick medical care. The window of opportunity for providing this care is very short - often only a few hours. Longer times can lead to disability or death.
Unfortunately, emergency medical help is not easily available to most of us. So, it is important to know the symptoms of an ailing heart and intervene early. Heath of your heart, in 99% of the cases, is in your own hand.
Hardened Arteries / Atherosclerosis
The build-up of cells, fat, and cholesterol - together known as plaque - in the arteries can lead to blood flow being blocked, preventing supply to the heart and brain. The inner walls of the arteries become narrow because of a build-up of plaque, causing hardening known as atherosclerosis. Atherosclerosis can cause heart attack or stroke.
Heart failure
Heart failure does not mean the heart stops, it is simply not pumping blood as it should. So the body does not get as much blood and oxygen as it needs. The quality of life for sufferers is poor and decreases over time - from difficulty exercising at first to problems with simple tasks such as dressing later.
Angina
Angina - a feeling of pain, heaviness, tightness, burning or squeezing in the chest - is caused by reduced blood supply to the heart muscle typically due to narrowing of the coronary arteries. Angina is debilitating and has serious impact on quality of life. This condition can eventually lead to a heart attack.
Heart attack
A heart attack, also known as myocardial infarction, occurs when blood flow to part of the heart is blocked, often by a clot. This is usually caused by atherosclerosis - hardening of the artery walls. The clot, is caused by rupturing or tearing of plaque in an artery. If blood supply is cut off for a long time, muscle cells are irreversibly damaged and can also die, leading to disability or death depending on the extent of the damage.
High blood pressure / Hypertension
Hypertension exists where the pressure at which blood is pushing against blood vessel walls is consistently above average. It forces the heart to work harder than normal. When it is forced to work harder than normal for an extended time, the heart enlarges and weakens. Arteries also suffer the effects of high blood pressure, becoming scarred, hardened and less elastic - leading to atherosclerosis and eventually heart attack.
Abnormal heart rhythm
Heartbeats can be too slow, known as bradycardia and can cause fatigue, dizziness, light-headedness or fainting. A heart beat which is too fast, tachycardia , can produce palpitations and is also responsible for dizziness, light-headedness and fainting.
Ventricular fibrillation , where the lower chambers quiver and the heart cannot pump any blood is life threatening. In atrial fibrillation, the two upper chambers of the heart - the atria - quiver instead of beating properly, and blood is not properly pumped out of the heart. As a result it may form clots and cause stroke.
Heart muscle disease
The most common - hypertrophic cardiomyopathy - is the biggest cause of sudden death in people aged under 30. The heart muscle thickens greatly without any obvious cause. In most cases the disease is hereditary, resulting from a gene abnormality.
Dilated, or congestive, cardiomyopathy is more common and occurs due to enlarging and stretching of the heart cavity, weakening the heart so it does not pump normally. The heart muscle becomes weak and too flexible, preventing it pumping blood efficiently around the body. The cause of the condition is unknown in many cases, but it can be caused by a virus, or auto-immune diseases.
In Arrhythmogenic Right Ventricular Cardiomyopathy, the heart muscle is replaced by fibrous scar and fatty tissue - the right ventricle tends to be most affected. The right side of the heart may first thicken and later dilate - become thinner. It may lead to disordered electrical activity, and in some cases problems with the heart's pumping action.
Restrictive cardiomyopathy is the least common form and occurs when the middle layer of the heart cavity wall - the myocardium - is excessively rigid, impairing the filling of the ventricles with blood between heartbeats.
Heart valve disease
There are four valves. If one or more of the four heart valves are diseased or damaged it can affect the flow of blood. If the valve does not open fully, it obstructs the flow of blood - known as valve stenosis - which makes the heart pump faster to get blood past the obstruction. If the valve does not close properly, it will allow blood to leak backwards - called valve incompetence or valve regurgitation - which means the heart has to do more to pump the required volume of blood forwards. Both conditions put extra strain on the heart. The blood behind the affected valve will also be under increased pressure, leading to a build-up of fluid in the lungs or lower part of the body, depending on the valve affected.
Congenital heart defects
Congenital heart defects are present in about 1% of live births and are the result of development problems during pregnancy. Congenital heart defects take the form of holes between the chambers, blockages in the pathways from the heart to the lungs or the body, or abnormal connections between the chambers and vessels of the heart.
Footnote
This article is based on medical notes on BBC.
