EKG Flashcards
What are the steps to reading an EKG systematically?
- Standard
- Rate
- Rhythm
- Axis
- Intervals
- Enlargement/Hypertrophy
- AVB
- BBB and Hemi-block
- Pre-excitation
- Ischemic changes
Define bradycardia.
<60 bpm
Define tachycardia.
> 100 bpm
1 small box = ?
0.1 cm = 0.04 s = 0.1 mV
1 large box = ?
0.5 cm = 0.2 s = 0.5 mV`
Heart rate = ?
300/large boxes
What is sinus rhythm?
- P wave before each QRS
- P wave upright in II, flipped in aVR
- All P waves identical in morphology
Normal PR interval = ?
0.12 - 0.2 s (3-5 small boxes)
Normal QRS interval = ?
0.07 - 0.11 s (2-3 small bocks)
Normal QT interval = ?
0.2 - 0.4 s OR < 40% of total cycle (RR interval)
Draw the axis. What is normal?
Look it up to confirm you are correct; -30 to 90 degrees
What changes are seen in RA enlargement?
- P wave amplitude > 2.5 mm (II, III, AVF)
- No change in p wave duration necessary
- Possible right axis deviation of P wave
When is RA enlargement seen?
Severe lung disease
What changes are seen in LA enlargement?
- 2nd half of P wave has an amplitude > 1 mm (V1)
- P wave duration > 0.04 seconds (II)
- No axis deviation necessary
When is LA enlargement seen?
Mitral valve disease
What changes are seen in RV hypertrophy?
- Right axis deviation > 100 degrees
2. R > S (V1) + S >R (V6)
When is RV hypertrophy seen?
COPD, congenital heart disease
What changes are seen in LV hypertrophy?
- R (V5 or V6) + S (V1 or V2) > 35 mm
- R (V5) > 26 mm
- R (V6) > 18 mm
- R (V6) > R (V5)
- R (aVL) > 13 mm (97% specific)**
- R (aVF) > 21 mm
- R (I) > 14 mm
- R (I) + S (III) > 25 mm
- LVH strain - ST depression with asymmetric inverted T waves in lateral leads
What indicates ischemia?
ST depression
What indicates infarction?
ST elevation
What is a standard EKG?
10 mm/mV voltage
25 mm/sec paper speed
What defines a first degree AV block?
PR >0.2 seconds, but P:QRS ratio still 1:1
What defines a second degree AV block?
P:QRS not 1:1