Page 152 - 84 human physiolofy part-1

Chapter 8

Acute myocardial infarction (AMI or MI), commonly known as a heart attack, A heart attack
occurs when the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in
a coronary artery. Often, this blockage leads to arrhythmias (irregular heartbeat or rhythm) that cause a
severe decrease in the pumping function of the heart and may bring about sudden death. If the blockage
is not treated within a few hours, the affected heart muscle will die and be replaced by scar tissue. It is
the leading cause of death for both men and women all over the world

Angina Pectoris

Angina Pectoris is chest pain due to ischemia (a lack of blood and hence oxygen supply) of the
heart muscle, generally due to obstruction or spasm of the coronary arteries (the heart's blood vessels).

Coronary Bypass

Coronary artery bypass surgery, coronary artery bypass graft surgery and heart bypass are surgical
procedures performed on patients with coronary artery disease for the relief of angina and possible
improved heart muscle function. Veins or arteries from elsewhere in the patient's body are grafted from
the aorta to the coronary arteries, bypassing coronary artery narrowing caused by atherosclerosis and
improves the blood supply to the myocardium (heart muscle).

Congestive Heart Failure

Congestive heart failure (CHF), also called congestive cardiac failure (CCF) or just heart failure, is
a condition that can result from any structural or functional cardiac disorder that impairs the ability of
the heart to fill with or pump a sufficient amount of blood throughout the body. It is not to be confused
with "cessation of heartbeat", which is known as asystole, or with cardiac arrest, which is the cessation
of normal cardiac function in the face of heart disease. Because not all patients have volume overload
at the time of initial or subsequent evaluation, the term "heart failure" is preferred over the older term
"congestive heart failure". Congestive heart failure is often undiagnosed due to a lack of a universally
agreed definition and difficulties in diagnosis, particularly when the condition is considered "mild".

Aneurysm

An aneurysm (or aneurism) is a localized dilation or ballooning of a blood vessel by more than
50% of the diameter of the vessel and can lead to instant death at anytime. Aneurysms most commonly
occur in arteries at the base of the brain (the circle of Willis) and in the aorta (the main artery coming
out of the heart) - this is an aortic aneurysm. This bulge in a blood vessel, much like a bulge on an
over-inflated inner tube, can lead to death at anytime. The larger an aneurysm becomes, the more likely
it is to burst. Aneurysms are also described according to their shape: Saccular or fusiform. A saccular
aneurysm resembles a small sack; a fusiform aneurysm is shaped like a spindle.

Dissolving Blood Clots

To dissolve blood clots you would use a drug that converts plasminogen (molecule found in
blood), to plasmin, (enzyme that dissolves blood clots).

Clearing Clogged Arteries

One way to unblock a coronary artery (or other blood vessel) is percutaneous transluminal

152 | Human Physiology