ECG axis determination

Question 1

LEAD I LEAD AVF
Positive Positive

axis will be

Answer 1

Normal (0 to +90 degrees)

Question 2

if lead I is positive and Lead AVF is negative what is AXIS

Answer 2

LAD possible
Is lead II positive?
Yes -> Normal (0 to -30 degrees)
No -> LAD (-30 to -90 degrees)

Question 3

If` lead I is negative and Lead AVF is positive what axis

Answer 3

RAD

+90 to 180 degrees

Question 4

if both lead I and AVF are negative what is the axis

Answer 4

Extreme Axis Deviation (-90 to 180 degrees)

Question 5

causes of left axis deviation

Answer 5

Causes of left axis deviation (LAD)
left anterior hemiblock
left bundle branch block
inferior myocardial infarction
Wolff-Parkinson-White syndrome* - right-sided accessory pathway
hyperkalaemia
congenital: ostium primum ASD, tricuspid atresia
minor LAD in obese people

Question 6

causes of right axis deviation

Answer 6

Causes of right axis deviation (RAD)
right ventricular hypertrophy
left posterior hemiblock
lateral myocardial infarction
chronic lung disease → cor pulmonale
pulmonary embolism
ostium secundum ASD
Wolff-Parkinson-White syndrome* - left-sided accessory pathway
normal in infant < 1 years old
minor RAD in tall people