Model for ECG Interpretation

Question 1

HR > 100 bpm, what is the conclusion?

Answer 1

tachycardia

Question 2

HR < 60 bpm, what is the conclusion?

Answer 2

bradycardia

Question 3

HR between 60-100 bpm, what is the conclusion?

Answer 3

normal resting HR

Question 4

HR between 100-210 w/ exercise, what is the conclusion?

Answer 4

usually normal response

Question 5

HR = speed

Answer 5

null

Question 6

Heart rhythm = conduction

Answer 6

null

Question 7

Heart Rhythm
QRS following every p-wave?

yes & normal rate?
no ->

Answer 7

• > normal sinus rhythm

- > nonconducted PAC or 2nd and 3rd degree A-V block

Question 8

Heart Rhythm
P-wave preceding every QRS?

yes & normal rate? ->
yes & tachycardia? ->
no, or abnormal p-wave? ->

Answer 8

• > normal sinus rhythm
• > normal with exercise or supraventricular tachycardia
• > PVC, AV nodal rhythm, AV block

Question 9

Heart Rhythm
Early beats?

yes? p-wave present, normal QRS? ->
yes? P-wave absent, long QRS? ->

Answer 9

• > PAC

- > PVC

Question 10

Heart Rhythm
Pauses?

yes? ->

Answer 10

-> sinus rhythm, nonconducted PAC, or 1st or 2nd AV block

Question 11

Heart Rhythm
total irregularity?

yes?

Answer 11

atrial or ventricular fibrillation

Question 12

PR interval

normal? ->
short? ->
long? ->

Answer 12

• > normal AV conduction
• > preexcitation syndrome (WPW or LGL)
• > 1st or 2nd AV block

Question 13

QRS Interval

normal? ->
long & normal rate? ->
long & tachycardia? ->

Answer 13

• > normal ventricular activation
• > bundle branch block
• > ventricular tachycardia or supraventricular tachycardia with aberrancy

Question 14

QRS Axis in frontal plane

QRS positive in both leads? ->
Lead I positive, aVF negative? ->
Lead I negative, aVF positive? ->
QRS negative in both leads? ->

Answer 14

• > normal axis
• > LAD
• > RAD
• > Indeterminate axis (no man’s land)

Question 15

Hypertrophy
Atrial

Check p-wave shape in lead II and V1, measure amplitude and duration

increased amplitude? ->
increased width, biphasic V1? ->

Answer 15

• > RAH

- > LAH or disease

Question 16

Hypertrophy
Ventricular

Evaluate QRS in leads V1 and V5-6

R-wave > 5 mm tall in V1? ->
Sum of S-wave in V1 and R-wave in V5-6 > 35mm?

Answer 16

• > RVH

- > LVH

Question 17

Ischemia/Infarction
Evaluate Q-waves, ST segments, and T-waves in ALL leads

abnormal Q-wave? ->
elevated ST-segment?->
depressed ST segment?->
inverted T-wave? ->

Answer 17

• > old MI
• > acute MI, sever ischemia or early repolarization
• > ischemia
• > may be ischemia or non-diagnostic