The Heart

Physiology & Anatomy

a. Purpose of the heart - The heart is basically a pump, pumping oxygen and nutrient
through the body.
b. There are tow cycles of the blood in the body - Peripheral body and lungs. The
blood is pumped to the lungs to get the oxygen and then through the whole body
to distribute the oxygen. Vessels that go out of the heart are called arteries and
vessels that go into the heart are called veins.
c. Two sides of the heart - The heart is actually composed of tow pumps – the right
one that pumps the blood of the lungs and is a lot smaller because cycle is smaller
and the left one that is bigger and pumps the blood of the body.
d. Basic Anatomic structure - Each side is composed of tow spaces: the atrium and
the ventricle. The atrium is smaller and receives the blood from the veins and
helps in pumping it to the ventricle. The ventricle is bigger and pumps the blood
out of the heart. The ventricle and the atrium are separated by a valve to prevent
blood flowing in the wrong direction. The heart is composed of special kind of
muscle that can contract continuously and can generate enough force to pump the
blood.
e. Electric Conductivity - The rhythm of the heart is set by special cells that conduct
electrical pulses through the muscles and cause them to contract at a certain pace.
f. Complete cycle – The blood is collected from the body filing the rght side of the
heart. The right atrium contracts a very short time before the ventricle to help
filing it. The period of time in which the heart is filled is called Diastole. Then
ventricle starts to contract and pumps the blood to the lungs. This period is called
Systole. At the same time, blood is collected from the lungs to the left side of the
heart from which blood is pumped out to the rest of the body in a similar way.
Arteries of the Heart – Coronary Arteries

They are also called coronary arteries, they are small but important because the
heart is a muscle that works continuously, it must get food blood supply all the time to
get oxygen needed for the energy it needs. The arteries that supply the heart go out of the
Aorta (The main artery that leaves the heart), right at it’s beginning when it emerges
from the left ventricle. Tow arteries leave the Aorta: The Left Main Coronary artery to
the left side of the heart and the Right Coronary Sinus to the right side of the heart.
These arteries later diverge to smaller arteries.
a. The main arteries of the left side of the heart – LCA (left coronary artery)
which branches into the LAD (Left anterior descending) that supplies blood
to the anterior wall of the heart and the circumflex branch which supplies
the posterior part.
b. The main arteries of the right side arteries – RCA (right coronary artery)
that supplies most of the right side of the heart. It has the Marginal branches
and is split at its end to the PDA (posterior descending artery) that supplies
the area between the ventricles.
The main arteries are then split to smaller arteries. Between the small arteries there are
connections that are called Anastomoses that are important as a natural bypass if there is
a blockage in one of them. There are many small variations of this classic picture of
arteries.
Diseases

There are many disease associated with the heart. Valve problems, Heart rate problems,
even tumors, but the most important one is the blockage of the coronary arteries. The
occlusions occur because of cholesterol, clotted blood and fat that sinks on the walls of
the arteries and gradually blocks them. The process is called atherosclerosis and it can
cause two major problems.
i. Angina Pectoris - It means Chest pain. It is a partial blockage of
the arteries and causes pains especially during exercise. The pain
can be in the chest or radiated to the shoulders or hands.
ii. Myocardial Infraction – Also known as heart attack and is the
most common cause of the death in the western world. It is caused
by a piece of the cholesterol and clotted blood that is torn from the
artery wall and moves deeper into it blocking it completely. This
stops the oxygen supply to the heart especially if a major vessel is
blocked. When oxygen supply stops, the area without supply can
stop functioning and die. This causes severe pain (“Like a truck
driving on the chest”).

Interventional Cardiology

This means inserting a character which is a tube through the blood vessels up to the heart.
It usually done from a vessel of the hand or leg. It is used for many purposes such as
measuring the blood pressure inside the heart, measuring the level of oxygen inside the
heart and measuring the electrical activity in the heart. One of the most important uses is
Angiography which is what Medcon records on the TCS systems.
The catheter is filled with iodine and it is injected into the arteries of the heart.
The chest is filmed with Reontgen film which shows the arteries filled with the dark
iodine. The result is imaging of the arteries of the heart. It is the best way to view the
state of the occlusions of the arteries and must be done before an operation.
 The second use is to treat the occlusion opening it with a balloon, a Stent or
Rotorblade. It is used both in angina to relieve pains and as an emergency procedure, up
to 8 hours after MI to allow the blood to go to the blocked areas often helping to reduce
the damage of the MI.
The third use of Angiography is measuring the functionality of the heart by
injecting iodine to the left ventricle (LV). The result can give information about how
much blood is pumped out of the heart in each stroke, how the walls of the heart are
functioning and if the valves work properly.

Problems

As anything in medicine there are also drawbacks.