What Is Coronary Artery Disease?
What Is Coronary Artery Disease?
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Newsfeed display by CaRP Coronary artery disease (CAD) occurs when the arteries that supply blood to the heart muscle (the coronary arteries) become hardened and narrowed. The arteries harden and narrow due to buildup of a material called plaque on their inner walls. The buildup of plaque is known as atherosclerosis. As the plaque increases in size, the insides of the coronary arteries get narrower and less blood can flow through them. Eventually, blood flow to the heart muscle is reduced, and, because blood carries much-needed oxygen, the heart muscle is not able to receive the amount of oxygen it needs. Reduced or cutoff blood flow and oxygen supply to the heart muscle can result in:

Angina. Angina is chest pain or discomfort that occurs when the heart does not get enough blood. Angina is chest pain or discomfort that occurs when your heart muscle does not get enough blood. Angina may feel like pressure or a squeezing pain in your chest. The pain may also occur in your shoulders, arms, neck, jaw, or back. It may also feel like indigestion.

Heart attack. A heart attack happens when a blood clot develops at the site of plaque in a coronary artery and suddenly cuts off most or all blood supply to that part of the heart muscle. Cells in the heart muscle begin to die if they do not receive enough oxygen-rich blood. This can cause permanent damage to the heart muscle.

A heart attack occurs when a clot in a coronary artery blocks the supply of blood and oxygen to an area of heart muscle, usually. Often, this blockage leads to arrhythmia, 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.

A heart attack is a life-threatening event. Everyone should know the warning signs of a heart attack and how to get emergency help. Many people suffer permanent damage to their hearts or die because they do not get help immediately.

Over time, CAD can weaken the heart muscle and contribute to:

Heart failure. In heart failure, the heart can’t pump blood effectively to the rest of the body. Heart failure does not mean that the heart has stopped or is about to stop. Instead, it means that the heart is failing to pump blood the way that it should.

Arrhythmias. Arrhythmias are changes in the normal beating rhythm of the heart. Some can be quite serious.

CAD is the most common type of heart disease. It is the leading cause of death in the United States in both men and women.

What Is Heart Failure?
Heart failure is a condition in which the heart can’t pump enough blood throughout the body. Heart failure does not mean that your heart has stopped or is about to stop working. It means that your heart is not able to pump blood the way that it should. The heart can’t fill with enough blood or pump with enough force, or both.

Heart failure develops over time, as the pumping action of the heart grows weaker. It can affect the left side, the right side, or both sides of the heart. Most cases involve the left side where the heart can’t pump enough oxygen-rich blood to the rest of the body. With right-sided failure, the heart can’t effectively pump blood to the lungs where the blood picks up oxygen.

The weakening of the heart’s pumping ability causes:
1. Blood and fluid to "back up" into the lungs.
2. The buildup of fluid in the feet, ankles, and legs.
3. Tiredness and shortness of breath.

Heart failure is a serious condition. About 5 million people in the United States have heart failure, and the number is growing. Each year, another 550,000 people are diagnosed for the first time. It contributes to or causes about 300,000 deaths each year.
Arrhythmias

An arrhythmia is any disorder of your heart rate or rhythm. It means your heart beats too fast, too slow, or with an irregular pattern. When the heart beats faster than normal, it is called tachycardia. When the heart beats too slow, it is called bradycardia.

Causes, incidence, and risk factors.
Normally, the 4 chambers of the heart - 2 atria and 2 ventricles, contract in a very specific, coordinated manner.

The electrical impulse that signals your heart to contract in a synchronized manner begins in the sinoatrial node (SA node), which is your heart's natural pacemaker.

The signal leaves the SA node and travels through the 2 upper chambers (atria). Then the signal passes through another node (the AV node), and finally, through the lower chambers (ventricles). The result is that the chambers contract in a coordinated fashion.

Problems can occur anywhere along this conduction system, causing various arrhythmias.

Examples include:
1. Supraventricular tachycardia - a fast heart rate that originates in the upper chambers (atria). The most common are atrial fibrillation or flutter, and atrioventricular nodal reentry tachycardia.
2. Ventricular tachycardia - a fast heart rate that originates in the lower chambers (ventricles).
3. Bradycardia - a slow heart rate due to problems with the SA node's pacemaker ability, or some interruption in conduction through the natural electrical pathways of the heart.

The risks of getting a tachycardia or bradycardia varies greatly, depending on the condition of your heart, any history of a prior heart attack, blood chemistry imbalances, or endocrine abnormalities.

Arrhythmias may also be caused by some substances or drugs. These include beta blockers, psychotropics, sympathomimetics, caffeine, amphetamines, and cocaine. Sometimes antiarrhythmic medications -- prescribed to treat one type of arrhythmia -- can actually cause another type of arrhythmia.

Some types of arrhythmias may be life-threatening if not promptly and adequately treated.

Symptoms:
1. Fast or slow heart beat.
2. Skipping beats.
3. Fainting.
4. Light-headedness, dizziness.
5. Chest pain.
6. Shortness of breath.
7. Skipping beats - changes in the pattern of the pulse.
8. Paleness.
9. Sweating.
10. Cardiac arrest.

The person may not have symptoms.
Signs and tests:
1. A doctor will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal.
2. The following tests may be performed to identify arrhythmias:
a. ECG.
b. Ambulatory cardiac monitoring for example, a Holter monitor, used for 24 hours, or loop recorders that may be worn for 2 weeks or longer.
c. Echocardiogram
d. Electrophysiology study (EPS)
e. Coronary angiography

If an arrhythmia is detected, various tests may be appropriate to confirm or rule out suspected causes. EPS testing may be performed to locate the origin of the arrhythmia and determine the best treatment, especially if a pacemaker implantation or catheter ablation procedure is being considered.

When an arrhythmia is serious, urgent treatment may be required to restore a normal rhythm. This may include intravenous medications, electrical "shock" therapy such as defibrillation or cardioversion, or implanting a temporary pacemaker to interrupt the arrhythmia.

Supraventricular arrhythmias may be treated with anti-arrhythmic drugs. However, most supraventricular arrhythmias can be treated and cured with radiofrequency ablation, eliminating the need for lifelong drug therapy.

Increasingly, most ventricular tachycardias are treated with an implantable cardioverter-defibrillator (ICD). As soon as arrhythmia begins, the ICD sends a shock to terminate it, or a burst of pacing activity to override it.
Bradycardias that cause symptoms can be treated by implanting a permanent pacemaker.

The outcome is dependent on several factors:
a. The kind of arrhythmia -- whether it is supraventricular tachycardia, or a more dangerous arrhythmia such as ventricular tachycardia or ventricular fibrillation, which are potentially fatal.
b. The overall pumping ability of the heart.
The underlying disease and its ability to be treated.

With bradycardias that are treated with a permanent pacemaker, there is usually a good outlook.

Complications:
1. Angina - chest pain caused by imbalance of supply and demand for oxygen in the heart muscle.
2. Heart attack
3. Heart failure
4. Stroke.
5. Sudden death

Call your provider if you develop any of the symptoms of a possible arrhythmia. Also call your provider if you have already been diagnosed with an arrhythmia, and your symptoms worsen or do not improve with treatment.

Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia. These steps include not smoking, eating a well-balanced, low-fat diet, and exercising regularly.
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Submitted: 08/01/06

Description: Coronary artery disease (CAD) occurs when the arteries that supply blood to the heart muscle (the coronary arteries) become hardened and narrowed. The arteries harden and narrow due to buildup of a material called plaque on their inner walls. The buildup of plaque is known as atherosclerosis. As the plaque increases in size, the insides of the coronary arteries get narrower and less blood can flow through them. Eventually, blood flow to the heart muscle is reduced, and, because blood carries much-needed oxygen, the heart muscle is not able to receive the amount of oxygen it needs.

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