EKGs: MIs & other S-T elevations Flashcards
what are the three EKG patterns of ischemia you should look for
- alwasy compare to an older EKG if avalible to see what patterns & changes may have occurred
- ischemia, injury & issue necrosis/apoptosis will result from an MI
- inverted T waves: indicated ischemia!!!
except: avR & V1 will always be downward (inverted) – so if they’re up – problem & III can be downward pointing - S-T segment depression indicates ischemia
- S-T segment elevation indicates infarction the worst of them all!!!
process of a myocardial infarction (atherosclerotic)
-if near the ventricles
- plaque buidlup within the wall of the vessel (cornary vessel)
- injury to the plaques top layer due to inflammation, direct injury, etc. creates a rupture
- the rupture forms a thrombus & that blocks the blood flow leading to occulsion of the vessel and ultimate damange
near the ventricle?
- PVCs (hypoxia)
- ventricular arrythimias (tachy, flutter,fib)
what will hyperkalemia appear as on EKG?
what can also appear this way?
hyperkalemia: results in sharp peaked T waves on EKG
- seen in pts. who skip dialysis
infarction also appears like this important to get a proper history of your pt.
Inverted T waves
- specifically what morphology
- what are other inverted t waves
- where will these appear
- where are the exceptions
- it will be symmetrical inverted t waves
- best seen in the precordial (v1-v6) leads
things to ddx.
- LVH: this will be not symmetrical in the inverstion and usually seen in V5/V6
- pediatric: can be normal finding
exceptions to inverstion
- avR will always be down
- V1 will always be down
- III can be down
S-T Depression
- indicates what
- where is it seen
- what can it indicate for EKG leads which may not paint a full picture
- what drug may give ST depression
S-T depression: indicates ischemic conditions (infarct is coming)
- indicates: subendocardial MI (not full thickness)
- can be seen in the pre-cordial leads
- S-T depression : in the V1 & V2 leads with a large R wave – can indaicte a posterior wall MI
- seen in NSTEMI
digitalis may given ST depression (heart strain can look like this too)
S-T Elevation
- what is the criteria & where
- what does it indicate
- what are some things which may mimic STE
- S-T elevations specifically > 1mm in any lead and > 2mm in men, 1.5 mm in women in the V2-V3 leads
- S-T elevation must be occuring in contiguous leads aka same family
- indicates myocaridal infarction death of full thickness
mimic STE?
- pericarditits
- brugade syndrome
- ventricualr aneurysum
- prinsmetal’s angina
- subarachnoid hemmorhage
how is necortis tissue indicated on an EKG?
the Q wave!! if the Q wave is deep, spikey and downward (it will be dramatic) this indicates there is infarction in this part of the heart –> meaning that there was a previous MI here
what are the geographic regions of the EKG & indications for which part of the herat (& which artery)
what about when looking for a posterior infarct
inferior heart: Right cornary artery (or LAD/Cx.)
seen in leads II,III, & avF
think diaphragmatic
suspect a right ventricular infarct: when the ST elevation is great in III>II suggests right wall
do NOT given nitro or morphine in r wall because that decrease preload & makes pt. hypotensive`
posterior heart: avR
- the opposite of V1 & V2 will tell you the posterior heart
- see a larger R (should be smaller in V1, V2)
- right cornary
lateral heart: circumflex artery
seen in leads I, avL, V5 & V6
anterior & septal: LAD artery
seen in leads V1, V2, V3, V4
*where V1 & V2 are closer to the septum & V3 & V4 are antero-lateral *
what is ventricular aneurysum
- when does it occur
- why does it occur
- where will you see & what will you see on EKG
- post-MI there is a ballooning of the heart wall at the point of infarction
- occurs on the EKG: see ST elevation where there are Q waves (pathological) in the same spot
- this indicates that there are Q waves- infarcted tissue & ST-elevation (infarction) occuring —not possible
- so its the ballooning of the heart muscle
What is Wellen’s Sign on EKG
- where do you see it
- what is it a finding of
- seen in V2 V3 on the EKG
- inverted T waves
- can also be BIPHASIC T waves – going up as much as theyre going down
- showing infarction of the proximal LAD
differential for Inverted T waves on EKG
(3)
how to differentiate them
- ischemia – think MI or signs of ischemia
- LVH: inverted T waves present
distinguish because they will not be symmetrical in their shape — itll have a long downward slope and then sharp upward like a hockey skate - pediatric EKG: will show T wave inversions but can be just a normal peds. finding
differential for ST depression on EKG
- ischemia!! think myocaridal ischemia first
- digitalis medication (if too much)
- Heart Strain
- will have a downward sloping style to it - hypokalemia
- depression occurs with the demand for flow being greater than the delivery of flow
differentials for ST elevation
- myocaridial infacrtion
- brugade syndrome
- ventricular aneurysum
- prinzementals angina
- SAH
- BET
- pericarditits
- hyperkalemia
what is Brugada syndrome
- pt. pop most likely
- presention of pt.
- findings on EKG
- treatment
- found most commonly in young healthy patients with no prior history of heart disease
- they will come in post-syncopal episode
EKG: downward slopping ST elevations shark fin sign
- specifically in leads V1-V3
- 3 types: all variations of downward sloping ST elevations
treatment: ICD asap!
Prinzmetal Angina
- pt. population
- what is happening & EKG findings
- young women with no atherosclerosis will have cornary vasospams of the vessles
- EKG: result of vasospasms will be transient ST elevations (not true infarction)
- treatment is nitrates and CCB
