Myocardial Infarction - Johnston Flashcards
Inverted T waves
Where usually?
Ischemia
- Chest leads (closest to ventricles)
Causes of MI (occlusion)
- Atherosclerosis
- Vasospasm
- Vasculitis
- Dissection
- Genetics
Chest pain, etc. not relieved by nitro or rest…Think what?
MI
Silent MI…think what?
Diabetics, elderly women
4 signs of new heart failure
- S3 gallop
- Crackles in lungs
- Increased JVD
- New murmur
Autonomic responses for…
Anterior MI vs. Inferior MI
Anterior - sympathetic (tachy, HTN)
Inferior - parasympathetic (bradycardia, hypotension)
EKG signs of STEMI
- Men - > 2mm STE (V2-V3)
- Women - > 1.5mm STE (2 or more contiguous leads)
- Maybe new LBBB
NSTEMI or NST ACS - EKG
ST depression, T wave inversion
Distinguishing NSTEMI from NSTE ACS
NSTEMI - elevated cardiac enzymes NSTE ACS (angina) - normal cardiac enzymes
Early phase of STEMI - EKG
What are they?
Tall hyperacute T waves
- Upward, slightly curved pattern
Causes of inverted T waves (7)
- Normal in children (V1-3)
- Myocardial ischemia
- BBB
- Ventricular hyper. w/ strain
- P.E.
- Hypertrophic cardiomy.
- Raised ICP
How to tell where the acute MI is occurring?
Where are the inverted T waves?
- Inferior = 2, 3, F
- Lateral = 1, L, V5-6
- Anterior = V2-6
ANY T-wave inversion in leads _____ is considered pathological
V2-V6
Other causes of STE?
- Pericarditis
- LVH w/ J point elevation
- Normal variant early repol.
Pericarditis - EKG
ST segment elevation, usually flat or slightly concave, with potentially the whole T wave elevated to the next P wave
Causes of ST depression?
- Subendocardial ischemia
- Stress test
- Digitalis toxicity
Diagnostic feature for infarction on EKG
Significant Q waves (NECROSIS) in the infarcted area leads