MI, Flash Pulmonary Edema, Cardiogenic Shock
Myocardial Infarction: “acute MI”; irreversible necrosis that results from an abrupt decrease or total cessation
of coronary blood flow to a specific area of the myocardium
STEMI: “ST elevation MI”; usually caused by a clot and fibrinolytic therapy is used if not contraindicated
NSTEMI: “non-ST elevated MI; usually caused by plaque
Manifestations:
o Tachycardia w/ or w/o ectopy: heart trying to compensate for decreased cardiac output and
ventricles are irritable because of hypoxia
o Bradycardia: if right sided MI
o Normotension or hypotension: hypoTN is left sided MI
o Tachypnea: from hypoxia, lungs are trying to get more O2
o Diminished heart sounds: decreased pressure causes valves to close softer which causes
decreased heart sounds
o S3: heart failure
o S4: hypertension
o Crackles: backup in lungs with left sided MI
o Pulmonary edema
o Air hunger
o Orthopnea
o Frothy sputum: HALLMARK SIGN
o Decreased CO
Decreased peripheral pulses
Slow capillary refill
o Decreased UO
o Decreased blood to brain
Restlessness
Confusion
Agitation
Anxiety
o Denial
o Anger
Patho:
Zone of ischemia: outermost ring of the MI; viable tissue if treated quickly; sign of past MI; can cause T-
wave inversion because of the hard time repolarizing
Zone of Injury: middle ring of the MI; will always be affected but is not dead tissue; will see ST elevation
if transmural; sign of MI happening now
Zone of infarction: dead and necrotic muscle; pathologic “Q-waves”
Transmural MI: “full thickness MI”; affects Endo-, Myo-, and Epicardium; will see Q-wave with
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, ST segment elevation
Subendocardial MI: multifocal areas; shows ST segment depression
12-lead ECG changes:
Alterations in depolarization (systole)
o Change in QRS complex
Alterations in repolarization (diastole)
o Change in ST segment (elevation or depression)
o Change in Q waves = Transmural MI
4 main arteries
Left main coronary artery:
o “Widow maker”: blockage here is the patient who falls dead because of the severity of blockage
in this artery
o Feeds all of the left atrium and left ventricle so if you lose this artery you lose the whole left side
of your heart which is the working side
Proximal Left Anterior Descending Artery:
o Anterior wall MI
o Can also call the “widow maker” it blockage is proximal enough because it affects the left
ventricle which is the most important
o ECG changes in leads V1, V2, V3, and V4
o Left ventricle pump failure Cardiogenic shock Death
o Will see hypoTN, tachycardia, tachypnea, decreased peripheral perfusion, decreased pulses,
skim mottling, decreased O2 sat, pink, frothy sputum (same as left sided heart failure)
o Failure to pump forward backing up into lungs!!!!!!!
Right coronary artery:
o Inferior wall MI
o ECG changes in leads II, III, aVf
o Common conduction problems
RCA perfuses SA node in 50%; circumflex perfuses other 50%
RCA perfuses AV node in 90%; circumflex perfuses other 10%
o Complications include:
Bradycardia if SA node goes out
Heart Block if AV node goes out
o Right ventricular infarction
Proximal section of right coronary artery
Can’t really pick up on 12-lead but can (not often) put electrodes on backwards and put
“R” on ECG
Can cause cardiogenic shock because if right side isn’t pumping, the left side doesn’t
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Myocardial Infarction: “acute MI”; irreversible necrosis that results from an abrupt decrease or total cessation
of coronary blood flow to a specific area of the myocardium
STEMI: “ST elevation MI”; usually caused by a clot and fibrinolytic therapy is used if not contraindicated
NSTEMI: “non-ST elevated MI; usually caused by plaque
Manifestations:
o Tachycardia w/ or w/o ectopy: heart trying to compensate for decreased cardiac output and
ventricles are irritable because of hypoxia
o Bradycardia: if right sided MI
o Normotension or hypotension: hypoTN is left sided MI
o Tachypnea: from hypoxia, lungs are trying to get more O2
o Diminished heart sounds: decreased pressure causes valves to close softer which causes
decreased heart sounds
o S3: heart failure
o S4: hypertension
o Crackles: backup in lungs with left sided MI
o Pulmonary edema
o Air hunger
o Orthopnea
o Frothy sputum: HALLMARK SIGN
o Decreased CO
Decreased peripheral pulses
Slow capillary refill
o Decreased UO
o Decreased blood to brain
Restlessness
Confusion
Agitation
Anxiety
o Denial
o Anger
Patho:
Zone of ischemia: outermost ring of the MI; viable tissue if treated quickly; sign of past MI; can cause T-
wave inversion because of the hard time repolarizing
Zone of Injury: middle ring of the MI; will always be affected but is not dead tissue; will see ST elevation
if transmural; sign of MI happening now
Zone of infarction: dead and necrotic muscle; pathologic “Q-waves”
Transmural MI: “full thickness MI”; affects Endo-, Myo-, and Epicardium; will see Q-wave with
Page 1 of 9
, ST segment elevation
Subendocardial MI: multifocal areas; shows ST segment depression
12-lead ECG changes:
Alterations in depolarization (systole)
o Change in QRS complex
Alterations in repolarization (diastole)
o Change in ST segment (elevation or depression)
o Change in Q waves = Transmural MI
4 main arteries
Left main coronary artery:
o “Widow maker”: blockage here is the patient who falls dead because of the severity of blockage
in this artery
o Feeds all of the left atrium and left ventricle so if you lose this artery you lose the whole left side
of your heart which is the working side
Proximal Left Anterior Descending Artery:
o Anterior wall MI
o Can also call the “widow maker” it blockage is proximal enough because it affects the left
ventricle which is the most important
o ECG changes in leads V1, V2, V3, and V4
o Left ventricle pump failure Cardiogenic shock Death
o Will see hypoTN, tachycardia, tachypnea, decreased peripheral perfusion, decreased pulses,
skim mottling, decreased O2 sat, pink, frothy sputum (same as left sided heart failure)
o Failure to pump forward backing up into lungs!!!!!!!
Right coronary artery:
o Inferior wall MI
o ECG changes in leads II, III, aVf
o Common conduction problems
RCA perfuses SA node in 50%; circumflex perfuses other 50%
RCA perfuses AV node in 90%; circumflex perfuses other 10%
o Complications include:
Bradycardia if SA node goes out
Heart Block if AV node goes out
o Right ventricular infarction
Proximal section of right coronary artery
Can’t really pick up on 12-lead but can (not often) put electrodes on backwards and put
“R” on ECG
Can cause cardiogenic shock because if right side isn’t pumping, the left side doesn’t
Page 2 of 9
