MYOCARDIAL INFARCTION (MI)
Dave Jay S. Manriquez
February 21, 2009
Coronary Artery Diseases
Coronary Artery Disease
CAD is a term that refers to the effect of the
accumulation of atherosclerosis plaque in the coronary
arteries that obstructs blood flow to the myocardium
conditions result from CAD
1. Angina Pectoris
2. Myocardial Infarction
Angina: Choking or suffocation.
Angina pectoris, is the medical term
used to describe acute chest pain or
Angina occurs when the heart’s need
for oxygen increases beyond the
level of oxygen available from the
blood nourishing the heart.
It has 3 types
Un stable angina &
Variant Angina (Prinzmetal’s or
resting angina) : doctors.blogspot.com
Types of Angina
People with stable angina have
episodes of chest discomfort
that are usually
predictable. That occur on
exertion or under mental or
Normally the chest discomfort
is relieved with rest,
nitroglycerin (GTN) or both.
It has a stable pattern of
onset, duration and intensity
of symptoms. www.health-nurses-
It is triggered by an un
predictable degree of
exertion or emotion.
severe than stable.
increasing frequency &
severity. Provoked by less
than usual effort,
occurring at rest &
interferes with pt
(Prinzmetal’s or resting
occur spontaneously with no
relationship to activity.
Occurs at rest due to spasm.
Pt discomfort that occurs
rest usually of longer
duration. Appears to by
cyclic & often occurs at
about the same time each
day (usually at night).
Thought to be caused by
coronary artery spasm
Mechanism Of Angina
Coronary atherosclerosis (atheroma )
Factors increasing preload :
Factors increasing after load:
Obstructive cardio myopathy
Coronary artery spasm
Characteristics: Squeezing, burning, pressing,
choking, or bursting pressure.
Onset: Quickly or slowly
Location: Chest, right or left arms,
shoulder, or neck, jaw.
Duration: Less then 5 minutes.
Associated: Dyspnea, Sweating, faintness,
palpitation, dizziness ect.
Relieving: GTN and rest.
Aggravating: exertion, exercise, heavy meal,
emotional upset, and anger.
Electrocardiogram ( ECG)
Exercise Electrocardiogram (Stress test).
Myo means muscle, “Cardiac”
heart, infarction means “death
of tissues due to lack of blood
It is also called heart attack.
It occurs when coronary
arteries become blocked and
the part of myocardial
muscles become dead due to
prolonged lack of oxygen
supply to the muscle cells.
Coronary artery cannot supply enough blood to the
heart in response to the demand due to CAD
Within 10 seconds myocardial cells experience
Ischemic cells cannot get enough oxygen or glucose
Ischemic myocardial cells may have decreased
electrical & muscular function
Cells convert to anaerobic metabolism.
Cells produce lactic acid as waste
Pain develops from lactic acid accumulation
3/19/2012 Pt feels anginal symptoms until receiving demand
increase 02 requirements of myocardial cells
ECG changes in Angina & MI
Zone of Ischemia: T wave inversion
Zone of Injury: ST elevation
Zone of Necrosis: Abnormal Q wave
Sign and Symptom
Classic symptom of heart attack
are chest pain radiating to neck,
jaws, back of shoulder, or left arm
The pain can be felt like:
Squeezing or heavy pressure
A tight band on the chest
An elephant sitting on the chest
Shortness of breath
Sweating, which may
3/19/2012 be profuse doctors.blogspot.com
Troponin T & I
Myocardial perfusion imaging
IMPORTANT INFORMATION TO
Increase supply of Decreasing the demand of
• Stop activity and lie down
•Take Tab. Angisid sublingually
and wait till it dissolves.
If pain continues take up to 03
Tab. Angisid one every five
minutes. If pain is not relieved
yet take another tab. and rush to
IMMEDIATE MANAGEMENT OF MI:
To prolong life.
Minimize infarct size.
Reduce cardiac work.
Prevent and treat complications.
A) INITIAL TREATMENT:
OMI (oxygen, monitor and I/V line).
Check vital signs and O2 saturation.
ECG within 10 minutes and repeat ECG.
Blood samples for enymes, CBC, lytes, and lipid
Calcium Channel Blocker
Anti platelets / Anti coagulant
Coronary Artery Bypass Graft surgery
Acute pain R/T imbalance between myocardial
oxygen supply and demand
Ineffective tissue perfusion R/T interruption of
arterial blood flow
Ineffective coping R/T effects of acute illness and
major changes in life style
Impaired gas exchange related to ineffective
breathing pattern and decreased systemic tissue
Anxiety related to present status and unknown
future, possible lifestyle changes, pain, and
perceived threat of death.
Activity intolerance related to fatigue
Recognize the symptoms
Reduce your risk factors:
Keep your cholesterol at a normal level.
Keep your blood pressure under control.
Use techniques to ease stress.
Control blood sugar level.
COMPLICATIONS OF MI:
Bradycardia and heart block.
Cardiac rehabilitation provides a venue for
continued education, re-enforcement of lifestyle
modification, and adherence to a comprehensive
prescription of therapies for recovery from MI,
which includes exercise training
Goals of Rehabilitation program:
Develop a program for progressive physical
Lives as full, vital and productive life
Remain within the limits of the heart’s ability to
respond to increases in activity and stress.