EKG Quick Reference Chart
Rhythm
Route
P Wave PR Interval
QRS
Rate
Rate
Rhythm
Regularity
Life
Threatening
No
Dependant
on Cause
Normal Sinus
Normal
Sinus Bradycardia Normal
0.12-0.20
0.12-0.20
<0.12
<0.12
60-100
<60
Regular
Regular
Sinus Tachycardia Normal
0.12-0.20
<0.12
>100, usually
100-150
Regular
No
Depends on
length and
frequency
Dependant
on
ventricular
rate
Dependant
on
ventricular
rate
Atrial Pause
Looks like SR but drops a complex Normal or
slow
Irregular
Atrial Flutter
Saw
tooth
None
<0.12
Atrial rate
250-400
Regular or
Irregular
Atrial Fibrillation
Wavy
None
unident
ifiable
<0.12
Atrial rate
>400
Irregular
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Causes
Normal Finding
Sleep, inactivity, athletic, vagal
tone, drugs, MI, K+, respiratory
arrest
Caffeine, exercise, fever, anxiety,
heart failure, drugs, pain, hypoxia,
hypotension, volume depletion
Elderly, digoxin toxicity, MI,
rheumatic fever
Valvular heart disease, MI, CHF,
pericarditis
Heart disease, pulmonary disease,
emotional stress, excessive
alcohol or caffeine
Junctional
Rhythm
Accelerated
Junctional
Rhythm
Junctional
Tachycardia
Supraventricular
Tachycardia
INVERT
ED
before
or after
QRS or
absent
INVERT
ED
before
or after
QRS or
absent
INVERT
ED
before
or after
QRS or
absent
Pointed
or
hidden
in T
<0.12
<0.12
40-60
Regular
Dependant
on
ventricular
rate
Electrical impulse not arriving
from SA node, AV node fires at
inherent rate
<0.12
<0.12
60-100
Regular
Dependant
on
ventricular
rate
Digoxin toxicity, damage to AV
node
<0.12
<0.12
>100
Regular
Dependant
on
ventricular
rate
Same as SVT
Immeasur
able
<0.12
150-250
Regular
Dependant
on rate and
patient
ability to
tolerate
Caffeine, CHF, fatigue, hypoxia,
mitral valve disease, altered
pacemaker in heart
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Idioventricular
Rhythm
None
None
20-40
Regular
Yes
Digoxin toxicity, acute MI
150-250
Regular
Yes, may
have pulse
MI, ischemia, digoxin toxicity,
hypoxia, acidosis, ↓K+, ↓BP
None
>0.11
wide and
bizarre
>0.11
wide and
bizarre
None
Ventricular
Tachycardia
None
None
Ventricular
Fibrillation
None
None
Yes, no
pulse
Follow PVC, VT, most common
cause of sudden death
Possibl
e
Normal
None
None
None
Irregular, vary
in size, shape
and height
No QRS
Asystole
Yes
>0.20
<0.12
Varies
Usually Not
2° AV Block Type
I
Normal
Varies:
progressiv
ely
prolonged
<0.12
Varies
2° AV Block Type
II
Normal
Consistent Normal or
normal or wide
prolonged
Regular or
irregular
Regularly
irregular: QRS
dropped after
progressively
prolonged PRI
Regular or
irregular;
occasionally
dropped QRS
Follows VT/VFib, acidosis, hypoxia,
↓K+, hypothermia, drug overdose
First sign of increasing AV block
1° AV Block
Usually slow
Usually Not
Acute inferior MI, digoxin toxicity,
vagal stimulation, conduction
system disease
Dependant
on overall
ventricular
rate, may
progress to
3° AV Block
BBB, anterior MI, lesions of
conduction system
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3° AV Block
Normal
Premature Atrial
Contractions
Yes,
PAC P
wave
shaped
differe
nt
Inverte
d
before
or after
QRS or
absent
None
Premature
Junctional
Contractions
Premature
Ventricular
Contractions
No
Wide
relationshi
p between
PR & QRS
May differ <0.12
from
underlying
rhythm
Slow
Regular
Yes:
pacemaker
needed
Rate of
underlying
rhythm
PAC
complexes
come early
No
<0.12
<0.12
Rate of
underlying
rhythm
PJC make it
irregular
No
Vagal tone, stress, caffeine,
alcohol, heart failure, digoxin
toxicity, ↓K+
N/A
>0.11
wide and
bizarre
Dependant
on
underlying
rhythm
Irregular due
to premature
beat
Depends on
frequency
and how
close to T
wave
Ventricular irritability, hypoxia,
↓K+, Ca, MI, digoxin toxicity,
anxiety
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Atria and ventricles beat
independently, digoxin or K+
toxicity, acute MI, ischemic heart
disease
Coffee, tea, alcohol, CHF,
emotions, fatigue, fever, hypoxia,
mitral valve disease