Wednesday, 28 January 2015

Heart Attack and Causes of Heart Attack

What Is a Heart Attack?
A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. If blood flow isn't restored quickly, the section of heart muscle begins to die.
Heart attacks are a leading killer of both men and women in the United States. The good news is that excellent treatments are available for heart attacks. These treatments can save lives and prevent disabilities.
Heart attack treatment works best when it's given right after symptoms occur. If you think you or someone else is having a heart attack (even if you're not fully sure), Call Medical Support Immediately.

Overview
Heart attacks most often occur as a result of coronary heart disease (CHD), also called coronary artery disease. CHD is a condition in which a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart.
When plaque builds up in the arteries, the condition is called atherosclerosis (ath-er-o-skler-O-sis). The buildup of plaque occurs over many years.
Eventually, an area of plaque can rupture (break open) inside of an artery. This causes a blood clot to form on the plaque's surface. If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.
If the blockage isn't treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.

Heart With Muscle Damage and a Blocked Artery

Figure A shows a heart with dead heart muscle caused by a heart attack. Figure B is a cross-section of a coronary artery with plaque buildup and a blood clot.
A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis.
Heart attacks can be associated with or lead to severe health problems, such as heart failure and life-threatening arrhythmias (ah-RITH-me-ahs).
Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Arrhythmias are irregular heartbeats. Ventricular fibrillation is a life-threatening arrhythmia that can cause death if not treated right away.

Don't Wait--Get Help Quickly
Acting fast at the first sign of heart attack symptoms can save your life and limit damage to your heart. Treatment works best when it's given right after symptoms occur.
Many people aren't sure what's wrong when they are having symptoms of a heart attack. Some of the most common warning symptoms of a heart attack for both men and women are:
  • Chest pain or discomfort. Most heart attacks involve discomfort in the center or left side of the chest. The discomfort usually lasts more than a few minutes or goes away and comes back. It can feel like pressure, squeezing, fullness, or pain. It also can feel like heartburn or indigestion.
  • Upper body discomfort. You may feel pain or discomfort in one or both arms, the back, shoulders, neck, jaw, or upper part of the stomach (above the belly button).
  • Shortness of breath. This may be your only symptom, or it may occur before or along with chest pain or discomfort. It can occur when you are resting or doing a little bit of physical activity.

Other possible symptoms of a heart attack include:
   Breaking out in a cold sweat
   Feeling unusually tired for no reason, sometimes for days (especially if you are a woman)
   Nausea (feeling sick to the stomach) and vomiting
   Light-headedness or sudden dizziness
   Any sudden, new symptom or a change in the pattern of symptoms you already have (for 
example, if your symptoms become stronger or last longer than usual)
Not all heart attacks begin with the sudden, crushing chest pain that often is shown on TV or in the movies, or other common symptoms such as chest discomfort. The symptoms of a heart attack can vary from person to person. Some people can have few symptoms and are surprised to learn they've had a heart attack. If you've already had a heart attack, your symptoms may not be the same for another one. 

Quick Action Can Save Your Life: Call Medical Support Immediately
If you think you or someone else may be having heart attack symptoms or a heart attack, don't ignore it or feel embarrassed to call for help. Call for emergency medical care. Acting fast can save your life.
Do not drive to the hospital or let someone else drive you. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room. Take a nitroglycerin pill if your doctor has prescribed this type of treatment.

Outlook
Each year, close to 1 million people in the United States have heart attacks, and many of them die. CHD, which often results in heart attacks, is the leading killer of both men and women in the United States.
Many more people could survive or recover better from heart attacks if they got help faster. Of the people who die from heart attacks, about half die within an hour of the first symptoms and before they reach the hospital.

Other Names for a Heart Attack
   Myocardial infarction (MI)
   Acute myocardial infarction (AMI)
   Acute coronary syndrome
   Coronary thrombosis
Coronary occlusion

What Causes a Heart Attack?

Coronary Heart Disease
A heart attack happens if the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. Most heart attacks occur as a result of coronary heart disease (CHD).
CHD is a condition in which a waxy substance called plaque builds up inside of the coronary arteries. These arteries supply oxygen-rich blood to your heart.
When plaque builds up in the arteries, the condition is called atherosclerosis. The buildup of plaque occurs over many years.
Eventually, an area of plaque can rupture (break open) inside of an artery. This causes a blood clot to form on the plaque's surface. If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.
If the blockage isn't treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.

Coronary Artery Spasm
A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis.
What causes a coronary artery to spasm isn't always clear. A spasm may be related to:
   Taking certain drugs, such as cocaine
   Emotional stress or pain
   Exposure to extreme cold
   Cigarette smoking
The animation below shows how plaque buildup or a coronary artery spasm can lead to a heart attack. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.




Words Credit: NIH (National Institute of Health)
http://www.nhlbi.nih.gov/health/health-topics/topics/heartattack
Pic Credit: Google and NIH
Video Credit: Youtube

No comments:

Post a Comment