Acute Myocardial Infarction or more commonly known as Heart attack occurs when there is a prolonged deficiency or lack of oxygen in the Heart.
Often this comes as a result of a thrombus that occludes the vessels leading to the heart.
A thrombus is basically a blockage in the heart that doesn’t allow blood to flow.
When the blood can’t flow – oxygen deprivation of the tissue occurs.
The heart muscle can be damaged.
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 area has a build-up of plaques and lipids such as cholesterol.
The location of MI depends on which artery is affected.
A “silent” heart attack occurs when the patient doesn’t have typical or any chest pains.
Other causes of a Heart Attack
- Coronary artery dissection
- and more
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
- Related to ST segment elevation
- Lack of Physical Activity
- Excessive Alcohol abuse
- Previous Heart Attack
- Previous Stroke
- Coronary Heart Disease
- High LDL
- Low HDL
- High Blood Pressure or Hypertension
- Chronic Kidney Disease
- Chest Pain
- Chest Discomfort
- Angina that doesn’t resolve with nitroglycerin
- Heart racing
- Fatigue -can be- more often in women
- Weakness -can be- more often in women
- 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.
Chest X-ray may be helpful
Echocardiography can shows functionality of heart
Technetium-99m pyrophosphate scintigraphy can help diagnoses acute MI
MRI can show extent of MI
- Can occasionally return blood flow.
- A catheter is inserted
- Done under fluoroscopy (set of specialized X-rays)
. Clopidogrel (Plavix)
Primary Percutaneous Coronary Intervention
Coronary artery bypass surgery