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Acute Myocardial Infarction or more commonly known as Heart attack occurs when there is a prolonged deficiency or lack of oxygen in the Heart.

A heart attack can occur as the result of a thrombus that occludes the vessels leading to the heart. This a blockage in the heart that doesn’t allow blood to flow.

When the blood can’t flow as it normally does, oxygen deprivation of the tissue occurs. This is often called Hypoxia. When hypoxia lasts long term, the heart muscle can be damaged or destroyed.

The damaged area can be temporary – if blood flow is restarted quickly – but it is more often permanent. The event is considered “acute” if it is sudden and very serious.

Often a thrombus rests or starts from at a preexisting site of Atherosclerosis. This is an area that has a build-up of plaques and lipids such as cholesterol. It is often the arteries and veins that surround the heart.

The location of MI or heart attack depends on which artery is affected. The symptoms of the heart attack can also be different depending on where the affected tissue or damage is occuring. A “silent” heart attack occurs when the patient doesn’t have typical or any chest pains.

Other Potential Causes of a Heart Attack

–  Vasospasm
–  Hypotension
–  Coronary artery dissection
–  Cocaine
–  and more

Some of the Main Locations:

1.)  Anterior descending branch of left coronary artery = Anterior Left Ventricle and Interventricular septum
2.)  Left circumflex artery = Anterolateral or Posterolateral
3.)  Right Coronary = Posteroinferior of Left Ventricle
4.)  Right Coronary = AV node and Sinus node

Q wave vs. Non Q wave infarction

–  This is related to ST-segment elevation that is seen on an EKG
–  EKG is done in a hospital or Emergency Room Setting that helps identify the cause of Chest Pain
–  An EKG gives a good look at what is occuring – though the EKG can look at a lot of different things.

Most Common Risk Factors

–  Age
–  Smoking
–  Lack of Physical Activity
–  Excessive Alcohol abuse
–  Previous Heart Attack
–  Previous Stroke
–  Coronary Heart Disease
–  Arteriosclerosis
–  High LDL
–  Low HDL
–  Obesity
–  High Blood Pressure or Hypertension
–  Diabetes
–  Chronic Kidney Disease
–  Stress

Potential Symptoms

–  Chest Pain
–  Chest Discomfort
–  Nausea
–  Vomiting
–  Angina that doesn’t resolve with nitroglycerin
–  Sweating
–  Heart racing
–  Anxiety
–  Light-headedness
–  Fatigue -can be- more often in women
–  Weakness -can be- more often in women

Laboratory Findings

Blood work is often essential in the early parts of dectection of a heart attack. Blood work will look at a lot of different things.

There is blood work that looks closely at the damage to the heart as a muscle. When this occurs, enzymes and molecules can be searched for, indicating damage.

–  CK-MB
–  Troponin I
–  Troponin T

Possible ECG Findings

–  Peaked T waves
–  ST-segment elevation
–  Q wave development
–  T wave inversion
–  Many heart attacks are similar and will have similar ECG findings
–  But not all heart attacks will always have the same ECG findings.

Diagnosis

–  Chest X-ray may be helpful
–  Echocardiography can show the functionality of the heart
–  Technetium-99m pyrophosphate scintigraphy can help diagnoses acute MI
–  MRI can show extent of MI.

Angiography

–  This procedure can occasionally return blood flow.
–  It is when a catheter is inserted into the vein and continues all the way to the heart
–  The goal is to get a real look, and possibly remove any blockage around the heart.
–  It is done under fluoroscopy (set of specialized X-rays)

Treatment

1.)  Medications

.  Nitroglycerin
.  Aspirin
.  Clopidogrel (Plavix)
.  Oxygen
.  Morphine
.  Alteplase
.  Reteplase
.  Tenecteplase
.  Heparin

2.)  Coronary Angiography

3.)  Primary Percutaneous Coronary Intervention

4.)  Coronary artery bypass surgery