Myocardial infarction is the medical name of a heart attack. A heart attack is a life-threatening condition that occurs when blood flow to the heart muscle is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the coronary arteries.Symptoms include tightness or pain in the chest, neck, back or arms, as well as fatigue, lightheadedness, abnormal heartbeat and anxiety. Women are more likely to have atypical symptoms than men. Treatment ranges from lifestyle changes and cardiac rehabilitation to medication, stents, and bypass surgery.

1. MYOCARDIAL INFARCTION
PRESENTED BY
R.PRIYA

2. INTRODUCTION
Myocardial infarction, the medical term for heart attack, literally means "heart tissue
damage or death." Heart attacks most commonly occur when one or more of the
coronary arteries — a network of blood vessels that supply blood to the heart —
become blocked.
More than 1.2 million Americans suffer a heart attack each year. Approximately
one-third of those who experience heart attack will die from it.
Fortunately, you can take several steps to prevent heart attack — starting with
healthy lifestyle choices and seeking preventive medical care.

3. DEFINITION
A heart attack is a medical emergency. A heart attack usually occurs when a blood clot
blocks blood flow to the heart. Without blood, tissue loses oxygen and dies.A heart
attack happens when something blocks the blood flow to heart so it can’t get the oxygen it
needs.
More than a million Americans have heart attacks each year. Heart attacks are also called
myocardial infarctions (MI). "Myo" means muscle, "cardial" refers to the heart, and "infarction"
means death of tissue because of a lack of blood supply.This tissue death can cause lasting
damage to your heart muscle..

4. TYPES
The three types of heart attacks are:
•ST segment elevation myocardial infarction (STEMI)
•non-ST segment elevation myocardial infarction (NSTEMI)
•coronary spasm, or unstable angina

5. TYPES

6. CAUSES
Conditions that can cause myocardial ischemia include:
•Coronary artery disease (atherosclerosis). Plaques made up mostly of cholesterol build up on
your artery walls and restrict blood flow. Atherosclerosis is the most common cause of myocardial
ischemia.
•Blood clot. The plaques that develop in atherosclerosis can rupture, causing a blood clot. The
clot might block an artery and lead to sudden, severe myocardial ischemia, resulting in a heart
attack. Rarely, a blood clot might travel to the coronary artery from elsewhere in the body.
•Coronary artery spasm. This temporary tightening of the muscles in the artery wall can briefly
decrease or even prevent blood flow to part of the heart muscle. Coronary artery spasm is an
uncommon cause of myocardial ischemia.
Chest pain associated with myocardial ischemia can be triggered by:
•Physical exertion
•Emotional stress(There is a wide range of everyday situations and activities that involves
activation of sympathetic nervous system, and emotional stressors are described as trigger
caused by sympathetic arousal. Acute emotional arousal can trigger life-threatening arrhythmias
and the mechanisms of that risk have been recognized).

7. CAUSES
•Cold temperatures“(In cold weather, the blood vessels constrict, forcing your heart to work
harder. This pressure on the heart can in some cases lead to a heart attack)," This raises
blood pressure and increases the chances of blood clots forming, both of which are factors in
heart attacks and strokes
•Cocaine use (the most plausible mechanism for the development of myocardial infarction in the
cocaine user is coronary artery spasm at a time when oxygen demand is increased due to an increase in
heart rate and blood pressure that are accompanied by platelet activation, and together culminate in
coronary artery occlusion).
•Eating a heavy or large meal eating exceptionally heavy meals, especially for people who
have coronary artery disease or have suffered a previous heart attack.” Eating heavy meals
would be most dangerous for people who already have heart disease because their overall
risk is higher from the start
Sexual intercourse Large meals could be about as risky as sexual inter course or other sudden
triggers for heart attacks

8. RISK FACTOR
•Tobacco. Smoking and long-term exposure to secondhand smoke can damage the inside walls of arteries.
The damage can allow deposits of cholesterol and other substances to collect and slow blood flow in the
coronary arteries. Smoking causes the coronary arteries to spasm and may also increase the risk of blood
clots.
•Diabetes. Type 1 and type 2 diabetes are linked to an increased risk of myocardial ischemia, heart attack
and other heart problems.
•High blood pressure. Over time, high blood pressure can accelerate atherosclerosis, resulting in damage to
the coronary arteries.
•High blood cholesterol level. Cholesterol is a major part of the deposits that can narrow your coronary
arteries. A high level of "bad" (low-density lipoprotein, or LDL) cholesterol in your blood may be due to an
inherited condition or a diet high in saturated fats and cholesterol.
•High blood triglyceride level. Triglycerides, another type of blood fat, also may contribute to
atherosclerosis.
•Obesity. Obesity is associated with diabetes, high blood pressure and high blood cholesterol levels.
•Waist circumference. A waist measurement of more than 35 inches (89 centimeters) for women and 40
inches (102 cm) in men increases the risk of high blood pressure, diabetes, and heart disease.
•Lack of physical activity. Not getting enough exercise contributes to obesity and is linked to higher
cholesterol and triglyceride levels. People who get regular aerobic exercise have better heart health, which is
associated with a lower risk of myocardial ischemia and heart attack. Exercise also reduces blood pressure.

9. PATHOPHYSIOLOGY

10. SIGNS AND SYMPTOMS
Symptoms of a heart attack include:
•Angina: Chest pain or discomfort in the center of the chest; also described as a heaviness, tightness,
heaviness, tightness, pressure, aching, burning, numbness, fullness or squeezing feeling that lasts
for more than a few minutes or goes away and comes back. It is sometimes mistakenly thought to
be indigestion or heartburn.
•Pain or discomfort in other areas of the upper body including the arms, left shoulder, back, neck,
jaw, or stomach.
•Trouble breathing or feeling shortness of breath.
•Sweating or "cold sweat."
•Fullness, indigestion, or choking feeling (may feel like "heartburn").
•Nausea or vomiting.
•Light-headedness, dizziness, extreme weakness or anxiety.
•Rapid or irregular heart beats.

11. SIGNS AND SYMPTOMS
 Although most women and men report symptoms of chest pain with a heart attack, women are
slightly more likely than men to report unusual symptoms. More vague or less typical "heart"
symptoms reported in women include:
• Upper back or shoulder pain.
• Jaw pain or pain spreading to the jaw.
• Pressure or pain in the center of the chest.
• Light headedness.
• Pain that spreads to the arm.
• Unusual fatigue for several days.

12. DIAGNOSTIC EVALUATION
•History
•Physical examination
•Symptoms relating to ischemia
•Changes in the motion of the heart wall on imaging
•Demonstration of a thrombus on angiogram or at autopsy.
•Cardiac Troponin I or Troponin T - which are both very sensitive and specific and are the recommended laboratory tests for the
diagnosis of MI.
• Troponin is the recommended test for myocardial necrosis, however there is a marked variance in the diagnostic
thresholds among different assays. The test becomes abnormal within 2-12 hours of commencement of pain depending on
the sensitivity of the troponin assay, and remains abnormal for 7-10 days. Additional tests:
• Creatinine, Urea, Electrolytes, Glucose; Full blood count. If shock is present: Blood gas arterial. If Lipids studies are
required, blood should be collected within 24 hours, or the studies should be deferred for 8 weeks as cholesterol levels
decrease after myocardial infarction. Alternative cardiac marker:
• CKMB with CKMB/CK ratio - sensitive and specific, but inferior to troponin and to be used only if troponin is unavailable. It
may be of value to diagnose reinfarction.
• Myoglobin - sensitive, but non-specific. Peaks within 4 hours of the onset of pain. Not recommended due to lack of
specificity for cardiac damage.
• Creatine kinase (CK) - sensitive but not cardiac specific; only recommended in conjunction with CKMB.
• Aspartate aminotransferase, Lactate dehydrogenase - very low specificity; not recommended.
• Lactate dehydrogenase isoenzymes - reasonably sensitive and specific, remains abnormal for up to 7 days after onset of
pain; not recommended.

13. DIAGNOSTIC EVALUATION
• ECG Changes on an electrocardiogram (ECG), such as ST segment changes, new left bundle branch
block, or pathologic Q waves
•Chest X-ray. An X-ray image of your chest allows your doctor to check the size of your heart and its blood
vessels and to look for fluid in your lungs.
•Echocardiogram. Sound waves (ultrasound) create images of the moving heart. Your doctor can use this
test to see how your heart's chambers and valves are pumping blood through your heart. An echocardiogram
can help identify whether an area of your heart has been damaged.
•Coronary catheterization (angiogram). A liquid dye is injected into the arteries of your heart through a
long, thin tube (catheter) that's fed through an artery, usually in your leg or groin, to the arteries in your heart.
The dye makes the arteries visible on X-ray, revealing areas of blockage.
•Cardiac CT or MRI. These tests create images of your heart and chest. Cardiac CT scans use X-rays.
Cardiac MRI uses a magnetic field and radio waves to create images of your heart. For both tests, you lie on
a table that slides inside a long tubelike machine. Each can be used to diagnose heart problems, including
the extent of damage from heart attacks.

14. MANAGEMENT
•Aspirin. The 911 operator might tell you to take aspirin, or emergency medical personnel might give
you aspirin immediately. Aspirin reduces blood clotting, thus helping maintain blood flow through a
narrowed artery.
•Thrombolytics. These drugs, also called clotbusters, help dissolve a blood clot that's blocking
blood flow to your heart. The earlier you receive a thrombolytic drug after a heart attack, the greater
the chance you'll survive and have less heart damage.
Antiplatelet agents. Emergency room doctors may give you other drugs known as platelet
aggregation inhibitors to help prevent new clots and keep existing clots from getting larger.Aspirin is
continued indefinitely, as well as another antiplatelet agent such as clopidogrel .
•Other blood-thinning medications. You'll likely be given other medications, such as heparin, to
make your blood less "sticky" and less likely to form clots. Heparin is given by IV or by an injection
under your skin.
•Pain relievers. You might be given a pain reliever, such as morphine.
•Nitroglycerin. This medication, used to treat chest pain (angina), can help improve blood flow to the
heart by widening (dilating) the blood vessels.

15. MANAGEMENT
•Beta blockers. These medications help relax your heart muscle, slow your heartbeat
and decrease blood pressure, making your heart's job easier. Beta blockers can limit
the amount of heart muscle damage and prevent future heart attacks. such
as metoprolol or carvedilol is recommended to be started within 24 hours.
•ACE inhibitors. These drugs lower blood pressure and reduce stress on the heart.
Benazepril (Lotensin), Captopril, Enalapril (Vasotec) ,Lisinopril (Prinivil, Zestril)
•Statins. These drugs help control your blood cholesterol. (Lower LDL cholesterol.
Other medications, such as ezetimibe).
• within 90 to 120 minutes in STEMI then fibrinolysis, preferably within 30 minutes of
arrival to hospital, is recommended. Thrombolysis involves the administration of
medication that activates the enzymes that normally dissolve blood clots. These
medications include tissue plasminogen activator, reteplase, streptokinase,
and Tenecteplase.’

16. SURGICAL MANAGEMENT
•Coronary angioplasty and stenting. In this procedure, also known as percutaneous
coronary intervention (PCI), doctors guide a long, thin tube (catheter) through an artery in
your groin or wrist to a blocked artery in your heart. If you've had a heart attack, this
procedure is often done immediately after a cardiac catheterization, a procedure used to find
blockages.
•The catheter has a special balloon that, once in position, is briefly inflated to open a blocked
coronary artery. A metal mesh stent almost always is inserted into the artery to keep it open
long term, restoring blood flow to the heart. Usually, you get a stent coated with a slow-
releasing medication to help keep your artery open.
•Coronary artery bypass surgery. In some cases, doctors perform emergency bypass
surgery at the time of a heart attack. If possible, however, you might have bypass surgery
after your heart has had time — about three to seven days — to recover from your heart
attack.
•Bypass surgery involves sewing veins or arteries in place beyond a blocked or narrowed
coronary artery, allowing blood flow to the heart to bypass the narrowed section.
•likely remain in the hospital for several days after blood flow to your heart is restored and
your condition is stable.

17. COMPLICATION
•Heart attack. If a coronary artery becomes completely blocked, the lack of blood and
oxygen can lead to a heart attack that destroys part of the heart muscle. The damage
can be serious and sometimes fatal.
•Irregular heart rhythm (arrhythmia). An abnormal heart rhythm can weaken your
heart and may be life-threatening.
•Heart failure. Over time, repeated episodes of ischemia may lead to heart failure.

18. PREVENTION
There are many actions you can take to reduce your risk of a heart attack:
•Quit smoking.
•Exercise regularly.
•Eat a healthy diet, such as the Mediterranean or Dash diets.
•Lose weight if you are overweight.
•Manage any existing high cholesterol levels, high blood
pressure and/or diabetes.
•Keep all your medical appointments and be an active member of your
health. Seeing your healthcare providers on a regular basis can uncover any
heart-related issues quickly and treatment can begin immediately.
•Avoid acohol

19. THANK YOU