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PATIENTS

The Heart

Our heart is a two-sided pump. Its function is to guarantee the blood flow between the lungs, where blood is oxygenated, and the body tissues, where oxygen is used as nutriment for the tissues' cells.
 

HEART CHAMBERS

Our heart is made up of four chambers. The chambers are compartments like small rooms whose function is to store the blood and then push it outside.The two upper chambers, the atria, receive the blood returning into the heart through the veins. The two lower ones, the ventricles, pump the blood to the body through the arteries.

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The right atrium receives all the returning blood from the upper and lower parts of the body. It then transfers this blood through the tricuspid valve to the right ventricle, which then pumps it through the pulmonary valve out to the lungs. In the lungs, carbon dioxide is exchanged for oxygen, then the blood returns to the left atrium, which transfers it though the mitral valve into the left ventricle. The left ventricle then pumps the blood through the aortic valve out to the body though the arteries, where the blood supplies tissues with oxygen and removes carbon dioxide. The blood, now depleted of oxygen, is returned to the right atrium by the veins. The left part of the heart needs to exert a stronger force than the right part; therefore the left cardiac walls are thicker and stronger.


HEART VALVES

In our heart we have four heart valves, dividing the four heart chambers. The heart valves are made of two or three leaflets of thin tissue which open and close around 70 times a minute.
The atrioventricular valves separate the upper from the lower chambers; one of these is called the mitral valve, which divides the left atrium and the left ventricle, and the other is the tricuspid valve, found between the right atrium and the right ventricle. The tricuspid valve is so-called because it has three leaflets, while the mitral valve is called bicuspid, because it has just two leaflets. The mitral valve has a complex structure. Its cusps are retained by the cordae tendinae, which are linked to the papillary muscles. These structures avoid the prolapse of the valve edge into the atrium.
The outflow valves separate the heart from the two main arteries: the aorta and the pulmonary artery. The aortic valve separates the left ventricle from the aorta, the main artery that carries blood to the body. The pulmonary valve separates the right ventricle from the pulmonary artery. The aortic and the pulmonary valves are said to be semilunar because of their leaflets' shape, which are similar to a half moon. The aortic and pulmonary valves are thin structures, without any muscles; they open and close only thanks to blood pressure gradients.

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The heart valves close and open in a pulsatile way, filling and emptying the atria and the ventricles. They work as doors, letting in a precise quantity of blood flow in only one direction, and preventing blood backflow. If the blood flows back during the leaflets' closure, the backflow is called regurgitation. If the blood flows back when the leaflets are already closed, this is known as leakage regurgitation. If the heart valve is healthy, there is no regurgitation, neither when the valve is closing, nor when it is closed. Moreover, the valve lets blood flow smoothly, without any turbulence and any blood stasis, which could lead to blood clots.


BLOOD VESSELS

Blood flows in our body through a complex system of tubes. These tubes, called blood vessels, carry blood to and from every part of the body.
Types of blood vessels

Arteries

Blood vessels which carry oxygenated blood from the heart to the various part of the body.

Capillaries

Capillaries connect arteries to veins. Capillaries are the smallest of a body's blood vessels and are important for the interchange of oxygen, carbon dioxide, and other substances between blood and tissue cells.

Veins

Blood vessels which carry low oxygenated blood from the various part of the body to the heart.

Coronary Artery Disease

Coronary artery disease (CAD), also referred to as coronary heart disease, is a chronic disease caused by narrowed coronary arteries that limit the blood and oxygen flows to the heart. Coronary artery disease is the most common type of heart disease and it is one of the leading causes of death in both men and women in United States and Europe.
Coronary arteries constantly supply your heart with blood, oxygen and nutrients. When the arteries become narrowed or clogged and can’t supply enough blood to your heart, the result is coronary artery disease. Blood clot formation causes the coronary arteries to narrow, reducing blood flow. When one of the coronary arteries becomes severely or totally blocked, usually by a blood clot, the result can be a heart attack, also known as myocardial infarction. The part of the heart muscle that is not receiving the oxygen-rich blood that it needs, it will begin to die and some of the heart muscle may become permanently damaged.


Causes of CAD
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Coronary artery disease is caused by the narrowing or blockage of the coronary arteries caused by atherosclerosis, a condition known also as "hardening of the arteries." Atherosclerosis is a chronic inflammatory response in the walls of arteries. It is the build up of cholesterol and fatty deposits, called plaques, on the inner wall of the arteries. Atherosclerosis is gradual, often taking decades before the affected person is in danger of cardiovascular problems. As a plaque builds up, blood vessels gradually harden and narrow, and this can affect the flow of blood through the artery. Without adequate blood, the heart becomes starved of oxygen and the vital nutrients it needs to work properly. Ultimately, if one or more arteries become completely blocked, heart tissue will die, resulting in heart attack.
Healthy coronary arteries are shaped like hollow tubes with smooth and elastic walls. Unhealthy or diseased arteries are stiff or hardened and present obstructions (plaques) that can interfere with normal blood flow.

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The abnormal narrowing or obstruction in a blood vessel is called stenosis. The narrowing of the artery, because of the presence of plaques, restricts blood flow. Over time the plaque may calcify, reducing artery’s ability to expand and contract and narrows the artery, reducing the amount of blood that can flow through it. As a consequence, tissues supplied by the affected artery don’t receive enough blood and heart does not receive enough oxygen to work properly.
If one of these plaque deposit ruptures a blood clot can rapidly form and completely block the vessel. If the vessel is a coronary artery, it can lead to a heart attack.

CAD Risk Factors

Although the exact cause of hardening of the arteries in not known, atherosclerosis is usually caused by high cholesterol. High blood pressure, diabetes and smoking can also contribute to coronary artery disease. Physical inactivity and obesity are other factors that can lead to coronary artery disease.

CAD Symptoms

Patients suffering from coronary artery disease can experience regular episodes where the heart is not receiving enough oxygen-rich flow (Cardiac ischemia). Symptoms of coronary artery disease can range from mild to severe. The most common symptom of coronary artery disease is angina pectoris, also referred to as chest pain. Other symptoms include sense of heaviness, fatigue, shortness of breath, unexplained sweating, uneven or rapid heartbeats, weakness, dizziness, or loss of consciousness. If the patient feels no symptoms, this is called silent ischemia.
Unfortunately, some people have coronary artery disease or even heart attacks without ever experiencing any of these symptoms. This can be especially true for people with diabetes.

Heart Attack or Myocardial Infarction

Heart attack

is a medical condition that occurs when blood flow to a section of heart muscle becomes blocked, most commonly due to rupture of a vulnerable plaque. Heart attack is also known as myocardial infarction (AMI or MI), because part of the heart muscle (myocardium) may literally die (infarct). 
If the flow of blood isn’t restored quickly, the section of heart muscle becomes damaged from lack of oxygen and begins to die.

Signs and symptoms of heart attack

Chest pain is the most common symptom of acute myocardial infarction and is often described as a sensation of tightness, pressure, or squeezing.
It can be mild or severe. Other common symptoms of heart attack include upper body discomfort, shortness of breath, nausea vomiting or dizziness. The symptoms of angina can be similar to the symptoms of a heart attack. Angina usually lasts for only a few minutes and goes away with rest. Angina that doesn’t go away or changes from its usual pattern (occurs more frequently or occurs at rest) can be a sign of the beginning of a heart attack.

Treatment of Coronary Artery Disease

Early treatment can prevent or limit damage to the heart muscle. Once the diagnosis of heart attack is confirmed or strongly suspected, treatments to try to restore blood flow to the heart are started as soon as possible. Treatments include medications
and medical procedures.

Diagnosis of coronary artery disease

The diagnosis of coronary artery disease is based on patient’s symptoms, personal, family and medical history. The General Practitioner will listen to the description of your symptoms and will carry out a physical examination. If your General Practitioner thinks something should be investigated in greater depth, he may refer you to a cardiologist in order to conduct more specific tests, such as:
  • Blood tests. Blood tests can detect the amount of some markers in the bloodstream, which are released during a heart attack. Higher than normal levels of these proteins in the bloodstream is evidence of a heart attack. Commonly used blood tests include troponin tests, CK or
    CK-MB tests, and serum myoglobin tests.
  • An echocardiogram. This test uses sound waves to produce images of the inside of patient’s heart
  • Chest x-ray
  • An electrocardiogram (ECG). This test detects and records the electrical activity of the heart. The highly sensitive electrocardiograph machine detects heart’s irregularities, disease and damage by measuring the heart’s rhythm and electrical impulses.
  • Coronary angiography. Coronary angiography is a procedure using x-rays to examine the heart and blood vessels and is part of a procedure called cardiac catheterization. Cardiac catheterization is an invasive procedure imaging that allows the evaluation of the heart functioning. 
    A long, narrow tube called catheter is inserted trough a plastic introducer sheath. Then the catheter is guided through the blood vessels and advanced up to the coronary arteries with the aid of an x-ray machine. A contrast dye that can be detected on x-ray is injected into the blood stream trough the tip of the catheter. The x-ray machine then takes a series of images (angiograms), producing a detailed look of the inside of the heart. If the angiograms show the presence of a stenosis, which cannot be treated with oral medications, then another procedure, called angioplasty, may be used to restore the blood flow trough the artery.

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Treatments of coronary artery disease

There are three ways to treat atherosclerotic disease: medications, minimally invasive interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA), stent implantation, and surgery.

Medical therapy

Most patients with heart disease receive medication to help prevent a heart attack. A number of different kinds of medicines may be used to treat heart attack.
  • Thrombolytic medicines are used to dissolve blood clots that are blocking the coronary arteries.
  • Beta Blockers decrease the workload on the heart. Beta blockers also are used to relieve chest pain or discomfort and to help prevent additional heart attacks. Beta blockers also are used to correct arrhythmias (irregular heartbeats).
  • Angiotensin-Converting Enzyme (ACE) Inhibitors lower blood pressure and reduce the strain on the heart. They also help slow down further weakening of the heart muscle.
  • Anticoagulants thin the blood and prevent clots from forming in your arteries.
  • Antiplatelets (such as aspirin and clopidogrel) stop platelets (a type of blood cell) from clumping together and forming unwanted clots.
While medications do not eliminate the narrowing of arteries, they can help improve the efficiency of the heart and reduce symptoms such as chest pain (angina).

PTCA (Percutaneous Transluminal Coronary Angioplasty)

Coronary angioplasty (also called percutaneous coronary intervention PCI) is a medical procedure used to restore blood flow through coronary arteries that are narrowed or blocked by a blood clot.

CABG

Coronary artery bypass grafting is a surgery in which arteries or veins are taken from other areas the body and sewn in place to bypass blocked coronary arteries providing a new route for blood flow to the heart muscle.

 

GLOSSARY

Acute gain

The difference in lumen diameter before and immediately after intervention due to plaque removal and/or arterial expansion.

Angina pectoris

Commonly known as angina, 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.

Angiography

Procedure in which radiopaque dye is injected into the circulatory system in order to visualize the coronary arteries.

Angioplasty

Is the mechanical widening of a narrowed or totally obstructed blood vessel.

Angiographic restenosis

Is the quantitative measurement of restenosis within a treated lesion and is defined as a dichotomous event (i.e. either present or absent).
It is measured by QCA and it is defined as the percentage of patients with a diameter restenosis >50% at follow-up.

Antiplatelet

A drug that interferes with platelet aggregation. Examples: aspirin, ticlopidine, clopidogrel.

Arterial blood pressure

Force exerted by the blood on the arterial walls.

Arteries

Vessels that carry oxygenated blood from the heart.

Aspirin

Or acetylsalicylic acidis a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It also has an antiplatelet or "anti-clotting" effect and is used in long-term, low doses to prevent heart attacks, strokesand blood clot.

Atherosclerosis

Deposition of fatty substances, cholesterol, cellular waste products, calcium and fibrin (a clotting material in the blood) within the intima of the vessel wall.

Blood pressure

Refers to the force exerted by circulating blood on the walls of blood vessels, and constitutes one of the principal vital signs.

Blood vessel

Arteries, arterioles, capillaries, venules and veins.

CABG

Coronary Artery Bypass Graft.

Capillars

The smallest blood vessels, site of exchange of nutrients and other substances.

Cardiac ischemia

Is a restriction in blood supply to the heart through the coronary arteries.

Cholesterol

Is a lipid found in the cell membranes of all animal tissue and it is transported in the blood plasma of all animals.

CK

Creatine kinase (CK), also known as phosphocreatine kinase or creatine phosphokinase (CPK) is an enzyme expressed by various tissue types. Clinically, creatine kinase is assayed in blood tests as a marker of myocardial infarction.

CK-MB

CK isoenzyme (enzyme that differs in the amino acid sequence but catalyzes the same chemical reaction).

Clot

Fibrous network produced as end-product of blood coagulation; consists primarily of fibrin, an insoluble protein, platelet and red blood cells.

Coronary

The blood vessels that surround the heart like a crown and are responsible for maintaining adequate blood flow to the myocardium.

Coronary arteries

The vessels that supply the heart with oxygenated blood.

Coronary arteries disease (CAD)

Progressive narrowing of coronary arteries; also known as ischemic heart disease.

De novo lesion

Lesion that has never been treated by an invasive procedure.

Diabetes mellitus

Often referred to simply as diabetes, is a syndrome characterized by disordered metabolism and abnormally high blood sugar (hyperglycaemia) resulting from insufficient levels of the hormone insulin, with or without additional resistance to insulin's effects in many body cells.

ECG

An electrocardiogram (ECG or EKG, abbreviated from the German Elektrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical activity of the heart over time.

Endothelization

Proliferation of the endothelium, The endothelium is the thin layer of cells that line the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. Endothelial cells line the entire circulatory system, from the heart to the smallest capillary.

Elastic recoil

Difference between inflated balloon diameter and minimal lumen diameter upon balloon deflation after angioplasty; degree of elastic recoil depends on plastic changes in the atherosclerotic plaque and elastic characteristics of the arterial wall; most elastic recoil occurs within 30 minutes after balloon deflation and is associated with higher incidence of restenosis.

French

A scale used to measure diameter; 1 F = 0.013".

Foreshortening

Stent shortening that occurs when the stent is expanded.

Heart attack

When the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in a coronary artery.

Intimal proliferation / Intimal thickening

Generalized response to vessel injury caused by PTCA and other devices. Activation of the coagulation cascade and inflammatory cells results in the production of chemotactic and growth factors, which lead to thrombus formation, intimal hyperplasia, and accumulation of connective tissue matrix.

Intima

The inner lining of the blood vessel formed by the endothelial cells and a small amount of connective tissue.

Late loss

Difference in lumen diameter after intervention and at follow-up; reflects net effects of intimal hyerplasia, elastic recoil, and vascular remodeling.

Lesion

presence of a plaque inside an artery similar terms: stenosis, narrowing.


MACE (major adverse cardiac event)

Describes events that can occur after a PTCA procedure are closely monitored after stent procedures (i.e., death, Q/non Q wave, MI, revascularization, CABG/PTCA).

Myocardial infarction (MI)

Death of cardiac tissue due to prolonged oxygen deprivation; often called "heart attack".

Neointimal hyperplasia

Manifestation of "healing" after vessel injury, characterized by proliferation of modified vascular smooth muscle cells; common occurrence after all devices. Laser balloon angioplasty (thermal injury) and DCA may lead to greater intimal hyperplasia than other devices.

Occlusion

Blockage or obstruction as might occur in an artery.

Overlapping vessels

On fluoroscopy, vessels filled with radiopaque fluid appear in two dimensions to overlap but actually don’t in three dimensions; to diagnose a blockage, there must not be any overlapping vessels near the lesion site to obscure the view.

Percutaneous

Effected through the skin; introduction of an endocardial lead through a small puncture in the skin and into a vein.

P.O.B.A.

Plain Old Balloon Angioplasty; standard against which newer interventional techniques, including new technology balloons, are measured.

Platelets

Cell fragments that play integral roles in blood clotting; sometimes call thrombocytes.

Plaque

Abuildup of fatty deposits within the wall of a blood vessel.

Profile

As used in interventional cardiology, the smallest diameter an interventional device can attain which specifies the smallest diameter occlusion it can cross.

PTA

Percutaneous transluminal angioplasty, also known as PTCA.

PTCA

Percutaneous Transluminal Coronary Angioplasty: procedure that uses a balloon catheter to apply pressure to vascular occlusion to attain a larger lumen and improve blood flow.

Radiopaque

Does not allow x-rays to penetrate.

Recoil (percent)

Used in reference to elastic recoil of a vessel. The amount of spring-back a vessel experiences after it has been expanded post procedure.

Reference diameter

The diameter of the vessel being treated for PTCA or stent. Measurement may be proximal reference or distal reference diameter.

Re-occlusion

Repeat occlusion of the target vessel post procedure either by restenosis or abrupt closure.

Residual stenosis

Blockage that remains in the artery immediately after an interventional procedure (angioplasty, DCA, etc.).

Restenosis

Reoccurrence of a blockage at the same location where a previous intervention was performed; this reoccurrence is related to the treatment technique; if the reoccurrence happens later than six months, it is believed to be progression of the arteriosclerosis.

Serum myoglobin

Is a test that measures the amount of myoglobin in the blood (myoglobin is a protein in heart and skeletal muscles).

Silent ischemia

Is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue.

Smooth muscle cell

Muscle tissue that lacks cross striations on its fibers; involuntary in action and found principally in visceral organs.

Stenosis

Narrowing in an artery; similar to occlusion, blockage, plaque.

Sub-acute

Between acute and chronic, but with some acute features. After the patient is discharged from the cath lab but within the first 24 hours (used in reference to stent thrombosis).

Stent

Framework used to provide internal support in artery lumen to prevent closure and assure patency.

Smooth muscle cell proliferation

Rapid reproduction of smooth muscle cells.

Thrombosis

The formation of a blood clot.

TLR (target lesion revascularization)

"Clinically-driven" (recurrent symptoms and a positive stress test) revascularization of the original target lesion. Repeat revascularization of a residual stenosis > 50 percent in the absence of objective evidence of ischemia is not considered clinical restenosis.

Troponin

Is a complex of three proteins that is integral to muscle contraction in skeletal and cardiac muscle, but not smooth muscle.

TVR (target vessel revascularization)

Arepeat percutaneous intervention of the target vessel. TVR is an indicator of both stent’s performance in preventing restenosis, and revascularization to areas other than the original target lesion.

Total occlusions

Complete blockages in arteries that impede blood flow.

Veins

Carry blood back to the heart.

Vulnerable plaque

Is an atheromatous plaque which is particularly prone to produce sudden major problems, such as a heart attack or stroke.