EKG Flashcards
Inferior MI leads
II, III, aVF
Lateral MI leads
I, aVL, V5, V6
Posterior MI leads
AVR
Septal MI leads
V1, V2
Anterior MI leads
V3, V4
Time of a small box
0.04
Time of a big box
0.2
Number of Boxes and Rate
1 box-300 bpm
2 boxes- 150 bpm
3 boxes- 100 bpm
4 boxes- 75 bpm
Best place to look for p waves
Inferior limb leads
Define first degree AV block
Delayed conduction through AV node
Longer PR interval >200ms
2nd degree AV block
Aka Mobitz 1
Aka Wenckebach
Progressively longer PR interval with a non conducted (dropped) beat
2nd degree AV block Mobitz II
PR interval is constant with intermittent dropped beat
3rd degree heart block
No association between QRS and P waves, often more p waves than QRS- higher atrial rate
Inverted p waves indicate:
Lower atrial or junctional rhythms with retrograde conduction…
Know the axis
Method for determining QRS axis
- Find isoelectric lead- direction of vector is perpendicular to this lead
- Choose lead that is 90 degrees away
- If QRS is +, this is the axis
- If QRS is -, axis is 180 degrees from this lead
Causes of right axis deviation
RV strain (PE)
COPD (pulmonary hypertension)
Lateral STEMI
Causes of Left axis deviation
LBBB
Inferior MI
Wave characteristics in left atrial enlargement
Lead II Bifid P wave- (two connected waves)
Lead V1- biphasic
Right atrial enlargement
Peaked p wave (p pulmonale) >2.5mm leads II, III
Sokolow- Lyon index
EKG criteria for ventricular hypertrophy
S in V1 + R in V5 >35mm….
Pattern of strain in EKG
Downsloping ST depression with rapid UPSLOPE
Pathological Q waves
> 2mm deep
25% of QRS complex
ST/T abnormalities with Qs suggest true infarct
Small Qs are normal
ISCHEMIA in ST depression
> 1mm of horizontal or downsloping ST depression 60-80 msec after J point
Indications of acute posterior STEMI on EKG
Depression in V1-3 anterior
ST elevation in V7-9 posterior…
J point elevation
Can be benign
Osborn waves with hypothermia (notch?)
Widespread across ekg
<2mm
No reciprocal st depression
Pericarditis
Widespread concave ST elevation
PR depression
Reciprocal ST depression aVR and V1
Bundle branch blocks osmosis
Kaylie’s MI regions
Small box mm size
1 mm
Large box size mm
5mm
First sign of transmural injury
Broad peaked T waves
Will progress to ST elevation
First sign of transmural injury
Broad peaked T waves
Will progress to ST elevation
PE EKG pattern
However, the “S1Q3T3” pattern of acute cor pulmonale is classic; this is termed the McGinn-White Sign. A large S wave in lead I, a Q wave in lead III and an inverted T wave in lead III together indicate acute right heart strain.
J wave
J wave- widespread (like pericarditis) makes sense in the setting of hypothermia, no reciprocal changes, less than 2mm, notching present in inferior leads
J wave
J wave- widespread (like pericarditis) makes sense in the setting of hypothermia, no reciprocal changes, less than 2mm, notching present in inferior leads
Which leads show reciprocal ST depression in pericarditis
aVR and V1
Acls h’s
Hypovolemia
Hypoxia
Hydrogen ion acidosis
Hypo/hyperkalemia
Hypothermia
