EKG Reading Flashcards
What is the common method for determining rate?
Looking at how many large boxes are present:
300-150-100-75-60-50
What is the six second method for determining rate?
R-R intervals in 30 large boxes x 10
What is the mathematical method for determining rate?
300/# large boxes between R waves
How do you assess Rhythm and Intervals?
- Check the bottom rhythm strip for regularity (regular, regularly irregular, irregularly irregular)
- Check for a P wave before each QRS, QRS after each P
- Check for PR interval (for AV blocks) and QRS (for bundle branch blocks). Check for prolonged QT (i.e. QT interval > 1/2 the R-R distance)
- Recognize “patterns” such as atrial fibrillation, PVCs, PACs, escape beats, ventricular tachycardia, paroxysmal atrial tachycardia, AV blocks, and bundle branch blocks
What is the normal axis range?
- (+) Lead I, (+) Lead aVF
- (-30 to +90 degrees)
- Positive in lead I, negative in aVF, positive in lead II is also normal (-30 to 0)
What is left axis deviation?
- (+) Lead I, (-) Lead aVF
- (-30 to -90 degrees)
- Also requires negative lead II
What is right axis deviation?
- (-) Lead I, (+) Lead aVF
- (+90 to +180 degrees)
What is extreme axis deviation?
- (-) Lead I, (-) Lead aVF
- (-90 to -180 degrees)
What is the differential for Left axis deviation?
LVH, Left ant. Fascicular block, inferior wall MI
What is the differential for Right axis deviation?
RVH, Left post. Fascicular block, lateral wall MI
What does LVH (left ventricular hypertrophy) look like on EKG?
S wave in v1 or v2 + R wave in v5 or v6 > 35 mm, or AVL R wave > 12 mm
What does RVH (right ventricular hypertrophy) look like on EKG?
R wave > S wave in v1 and gets progressively smaller in v1 to v6
What leads are atrial hypertrophy seen in?
Leads II and v1
What do you see in RAH (right atrial hypertrophy)?
Peaked P wave in lead II > 2.5 mm amplitude. P wave in V1 has increase in initial positive defection
What do you see in LAH (left atrial hypertrophy)?
Notched, wide (>3 mm) P wave in II. V1 has increase in the terminal negative deflection.
How do you see ischemia on an EKG?
Symmetrical T wave inversion.
Look in leads I, II, and leads v2-v6
How do you see injury on an EKG?
Acute damage.
Look for ST elevation.
How do you see infarct on EKG?
“Pathologic” Q waves - To be significant, a Q wave must be at least one small square wide or 1/3 entire QRS height
Area of injury by lead:
V1-2
Anterioseptal wall
Area of injury by lead:
V3-4
Anterior wall
Area of injury by lead:
V5-6
Anteriolateral wall
Area of injury by lead:
II, III, aVF
Inferior wall
Area of injury by lead:
I, aVL
Lateral wall
Area of injury by lead:
v1, v2
Posterior wall (reciprocal)
What is the most common cause of Left Axis Deviation?
Left ventricular hypertrophy
How can you confirm Left Ventricular Hypertrophy after you’ve seen it on EKG?
ECHO or Chest X-ray
What will Dr. P ask about?
Left ventricular hypertrophy
How do you tell if there is left ventricular hypertrophy (according to Dr. P)?
Negative in V1 or V2 and Large positive R wave in V5 or V6 > 35 mm
What do you see in MIs?
Pathologic Q wave and inverted T waves
What do you see ST elevation in?
Ischemia (transmural infarction)
What do you see ST depression in?
Infarct (subendocardial infarction - can be seen after someone had previous MI)
What do you see in first degree heart block?
Prolonged PR interval but no missing QRS complexes.
What do you see in second degree heart block?
Some dropped QRS complexes
What do you see in 2nd degree heart block mobitz1?
Winckebach
- Key feature: PR interval progressively lengthens and then you drop the beat
- You have dropped beats every 4th, 5th or 6th cycle
What do you see in 2nd degree heart block mobitz2?
Randomly drop beats, with no pattern to it.
Unpredictable
What do you see in 3rd degree heart block?
Complete heart block
Very bad, need pacemaker and implantable defibrillator, all WRS and P waves are completely dissociated
What do you use to treat PVST?
Adenosine
-Flush fluids after, heart spots and then restores itself 6 seconds later
What do you see in PVST?
Can’t distinguish a single monomorphic P wave
What do you see in a right bundle branch block?
Right-Rabbit
-You tend to see rabbit ears in V1 (in place of R wave)
What do you see in left bundle branch block?
General widening of the QRS complex, may even look like a little ST elevation.
- Had to distinguish acute ischemia from LBBB - need to ask about symptoms and compare EKGs
- You can see this in multiple leads/all over