heart is a strong muscular organ about the size of your fist. It is in the
centre of your chest and is tilted slightly to the left. Its job is to pump
blood though the blood vessels, which takes oxygen and nutrients to all parts of
thick band of muscle tissue (the septum) divides the heart into two pumps, the right heart and the left heart.
Each side of the heart has a different function in the heart’s pumping
right side of the heart receives unoxygenated blood returning from
the organs of the body and pumps it to the lungs. There the blood picks up a
fresh supply of oxygen while carbon dioxide (a waste product) is breathed out.
left side of the heart receives the oxygen-rich blood from the lungs
and pumps it out through the aorta (main artery) to all parts of the body.
The right side and left side
of the heart are each made up of two chambers:
1) the upper chamber, called the atrium, and
2) the lower chamber, called the ventricle.
upper and lower chambers are connected by valves.
Valves are like one-way doors that allow the blood to flow through the heart in
only one direction. In both sides of the heart the blood is pumped from the atria
to the ventricles.
II: Blood Supply to the
Heart: Coronary Arteries
heart muscle itself must also be supplied with oxygen and nutrients in order for
it to keep working. These are delivered to the heart muscle through blood
vessels called coronary arteries.
There are two main coronary arteries:
1) the right
coronary artery, and
the left coronary artery, which
divides into two branches, the left anterior descending branch and the
two coronary arteries are located on the outside of the heart, reaching into the
heart muscle, supplying every portion of it with blood.
What Is Coronary Artery Disease?
Coronary Artery Disease is a process that gradually narrows the coronary
arteries. This is called atherosclerosis.
This narrowing of the coronary arteries is caused by fatty material (primarily
cholesterol) in the blood, which forms sticky plaques that attach to the inside
of the blood vessels. These plaques can get larger and larger, clogging the
arteries and damaging the arterial wall, which in turn may also trigger clot
– during exercise
– stressful situations
– exposure to cold or windy weather
– eating rich or large meals
heart must then beat faster, and needs more oxygen and nutrients to meet the
demand. The clogged coronary arteries restrict the heart’s ability to obtain
the oxygen and nutrients it needs. This reduction of blood supply to the heart
muscle causes the aching discomfort of angina.
What Is Angina?
Symptoms of Angina
have described the sensation in many ways, such as crushing, heavy-feeling,
squeezing, tightness, aching, pressure, choking, and even burning and tingling.
discomfort of angina usually occurs just under the breast-bone, located in the
centre of your chest, often spreading to the left shoulder and down the arm to
the back, or even up to the neck and jaw. Angina pain is often accompanied by
– difficulty in breathing, or
shortness of breath (SOB)
usually lasts three to five minutes, and will usually go away with rest.
an angina attack occurs,
1) stop whatever you are doing
2) rest until it passes
place a nitroglycerin tablet under your tongue, or use the spray
the pain is not promptly relieved, take another nitro every five minutes until a
total of three pills or sprays have been taken
you still have angina pain, go to the nearest emergency department
the medications that have been prescribed for you on a regular basis, and
exactly according to your doctor’s instructions.
– more frequent
– longer lasting
– provoked by less exertion
– occurs during rest
– wakes you at night.
– injury, and so on.
your doctor can determine the cause of your symptom.
What Is a Heart Attack?
most common type of heart attack is caused by coronary
thrombosis, which occurs when a clot (thrombus) blocks one or more of the
coronary arteries. Coronary thrombosis is one of the manifestations of coronary
may occur in a coronary artery that is totally free of atherosclerosis (as well
as in one that is heavily affected by that condition), and this may explain why
many people suffer angina and other cardiac problems without any evidence of
underlying blockage of the arteries.
Symptoms of a Heart Attack
heart attack can come on gradually, preceded by several attacks of angina over
days, weeks, months, or even years. But a heart attack may also occur without
any apparent warning and in people who have never previously experienced any
– discomfort or band-like
pressure, heaviness, tightness, burning or squeezing
indigestion, fullness or choking sensation across the chest or anywhere in the
– it may commonly spread to the
back, jaw, arms (especially the left arm)
may vary in intensity from tightness to one of agonizing crushing or bursting
– it may be continuous, or it
may last a few minutes, fade, and then recur
– it may be associated with
– nausea and/or vomiting
– loss of consciousness
– severe weakness
– shortness of breath
Reducing the Risk of Having a Heart Attack
variety of different approaches may be taken to deal with the underlying
coronary artery disease and to reduce the possibility of a heart attack:
Increased awareness of risk factors
and their correction play an important role in preventing or slowing down the
progression of heart disease.
Factors over which You Have No Control
– being male
– your age
– your family history
Factors that Can Be Altered
– cigarette smoking
– high blood pressure
– high blood cholesterol (LDL, or ‘bad’ cholesterol)
– low HDL (‘good’) cholesterol
– lack of exercise
Treatment. The use of drugs depends upon the nature of the heart attack and
underlying coronary disease. Antihypertensive drugs may be prescribed to lower
the blood pressure. Other drugs may be given to improve heart function, prevent
angina, or lower the level of blood cholesterol.
Treatment. Other forms of treatment are also available. Two (invasive) ones
– coronary artery bypass graft
– coronary angioplasty
Their use depends on individual