Myocardial infarction: Definition, Causes, Sign and Symptoms, Types, Diagnosis, Treatment, Risk factors, Complication, Prevention

 

Myocardial infarction

 

Definition of myocardial infarction:

 
A myocardial infarction (MI), also known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.
 
 

Causes of Myocardial infarction:

 
Coronary artery disease:
The main cause of myocardial infarction is coronary artery disease. A heart attack occurs when one of the heart's coronary arteries is blocked suddenly or has extremely slow blood flow.
A heart attack also is called a myocardial infarction. The usual cause of sudden blockage in a coronary artery is the formation of a blood clot (thrombus).
 

Sign and Symptoms:

 
The most common symptoms:
1.    Pressure or tightness in the chest.
2.    Pain the chest back, jaw and other areas of the upper body.
3.    Sweating.
4.    Nausea.
5.    Vomiting.
6.    Anxiety.
7.    A cough.
8.    Dizziness
9.    A fast heart rat.
Chest pain is the most common reported symptom among both men and women. However, women are more likely than men to have:
10.Shortness of breath.
11.Jaw pain- upper back pain.
12.Nausea and. Vomiting.
 

Types of myocardial infarction:

 
There are six types of myocardial infarction:
Type1: Infarction due to ischemia from a primary coronary event such as atherosclerotic plaque rupture and thrombus formation, arterial wall erosion, fissuring or dessection.
 
Type 2: Infraction secondary to ischemia from either oxygen demand or decrease supply (coronary artery spasm, hypotension, hypertension, anaemia).
 
Type 3: Sudden cardiac death/ arrest with symptoms suggestive of STEMI or thrombus in a coronary artery found in angiography or autopsy.
 
Type 4: Infarction resulting from percutaneous coronary intervention (PCI).
Type 5:  Infraction from stent thrombosis.
 
Type6: Infraction due to ischemia related to coronary artery bypass grafting (CABG).
 
 

Diagnosis:

 
A.   An electrocardiogram (EKG).
 
B.   Blood tests for serum cardiac markers:
Chemicals that are released into the blood when the heart muscle is damaged. The blood test that doctors order mist frequently ti diagnose a heart attack is called troponin.
 
C.   Additional test:
1.    An echocardiogram: A painless test uses sound waves to look at the heart muscle and heart valves.
2.    Radionuclide Imaging: Scans that use special radioactive isotopes to detect areas of poor blood flow in the heart.
 

Treatment:

 
Treatment is a myocardial infarction is time critical.
1.    Aspirin: Aspirin is an appropriate immediate treatment for a suspected MI. It is a powerful anti-platelet drug, with a rapid effect, which reduce mortality by 20%. Aspirin, 150-300mg should be swallowed as soon as possible.
 
2.    Nitroglycerin or opioids: may be used to help with chest pain.
 
 
3.    Heparin.
 
 

Risk factors:

 
1.    High blood pressure.
2.    High cholesterol levels.
3.    High triglycerides.
4.    Diabetes and high blood sugar levels.
5.    Obesity.
6.    Smoking.
7.    Age: Men are at a higher risk of a after age 45 and women are at a higher risk of a after age 55.
Others factor:
1.    Stress.
2.    Lack of exercise.
3.    The use of illegal drugs.
 
 

Complication:

 
 
1.    Complications of MI include complications of both ST – elevation Myocardial infarction and non STEMI usually occurring within 24 hours.
2.    Most complications present <24 hours after an acute MI, but mechanical complication may occur any time in the first week after an acute MI.
Complications during hospitalization for acute MI may include:
3.    Cardiogenic shock.
4.    Acute heart failure.
5.    Right ventricular infarction.
6.    Mechanical complication -such as, left ventricular (LV) septal rupture, left ventricular free wall rapture.
7.    Electrical complication: ventricular arrhythmias, atrioventricular block.
8.    Ischaemic complications: reinfarction.
9.    Pericardial complications: pericarditis.
 
 

Prevention:

 
Life style changes:
1.    Stop smoking.
2.    Eating healthy fully: Choose good nutrition. A healthy diet is the best weapons you have to fight cardiovascular disease.
3.    Lowering our LDL cholesterol.
4.    Controlling our blood pressure.
5.    Aim for a healthy weight.
6.    Manage diabetes.
7.    Reduce stress.