Axis & Chamber Enlargement

Question 1

Predominant direction is positive in Leads I and aVF, this indicates a ______ axis

Answer 1

normal

Question 2

Lead 1: Positive

aVF: Negative

Answer 2

LAD

Question 3

Range between 0 and -90 degrees…

Answer 3

LAD

Question 4

Lead 1: negative

aVF: Positive

Answer 4

RAD

Question 5

Lead 1: negative

aVF: negative

Answer 5

indeterminate/extreme axis

Question 6

range between 90 and 180

Answer 6

RAD

Question 7

Range between -90 and 180

Answer 7

indeterminate

Question 8

aVF degrees…

Answer 8

+ 90

Question 9

Lead I degrees

Answer 9

0

Question 10

The axis points in the direction of the lead with the ________ QRS complex in the frontal plane

Answer 10

tallest QRS complex

Question 11

The axis is ________ to a lead with an equiphasic QRS complex

Answer 11

perpendicular

Question 12

Positive deflection lead I = aVF

Answer 12

+45 degrees (halfway between 90 and 0)

Question 13

Positive deflection lead I > avF

Answer 13

axis between 0 and 45 (closer to Lead I)

Question 14

positive deflection lead I < aVF

Answer 14

axis between 45 and 90 (closer to aVF

Question 15

R wave in aVL > R wave in Lead I…

Answer 15

Strong LAD w. LAHB

Question 16

R wave in lead III > R wave in aVF

Answer 16

Strong RAD w. LPHB

Question 17

The below are causes of…

• Q waves of inferior myocardial infarction
• Chronic coronary artery disease
• Diffuse myocardial disease, such as
cardiomyopathy, amyloidosis, myocarditis, etc.
• Some cases of hyperkalemia
• Wolff-Parkinson-White syndrome with a rightsided
accessory pathway
• Left ventricular hypertrophy

Answer 17

LAD

Question 18

The below are causes of…

• Normal finding in children and tall thin adults
• Right ventricular hypertrophy
• Chronic lung disease even without pulmonary
hypertension
• Anterolateral myocardial infarction
• Left posterior hemiblock
• Pulmonary embolus
• Dextrocardia

Answer 18

RAD

Question 19

Who might have a vertical heart, with mean QRS axis toward 90 degrees?

Answer 19

tall, thin individuals

Question 20

Who may have a more horizontal heart, with the mean QRS shifting more leftward?

Answer 20

obese, pregnant

Question 21

Atrial enlargement is assessed in which leads?

Answer 21

II, V1

Question 22

P wave amplitude > 2.5 mm (2.5 boxes)

Answer 22

RAE, P Pulmonale

Question 23

P wave duration > 0.10s (2.5 boxes)

Answer 23

LAE, P Mitrale

Question 24

P wave amplitude > 2.5 mm (2.5 boxes) and duration > 0.10s (2.5 boxes)

Answer 24

Biatrial enlargement

Question 25

In lead V1, how is RAE identified?

Answer 25

upward deflection > downward deflection

Question 26

V1 P waves are usually...

Answer 26

biphasic

Question 27

The below are common conditions with... Pulmonic stenosis Tricuspid stenosis Tricuspid regurgitation

Answer 27

RAE

Question 28

In lead V1/V2, how is LAE identified?

Answer 28

negative deflection > 0.04s and > 1mm deep (1 box wide and deep) (prolonged and deep, scoop like)

Question 29

In LAE, what should you see in leads I, II, and V4 - V6?

Answer 29

notched, broad P wave

Question 30

The below conditions present with... Mitral stenosis Mitral regurgitation

Answer 30

LAE

Question 31

The below are common causes of what? * Hypertension * Valvular heart disease

Answer 31

LVH

Question 32

LVH can be diagnosed if the sum of the deepest ____ in ____/______ + tallest _____ in ___/_____ are > _____mm

Answer 32

deepest S in V1 or V2 + tallest R in V5 or V6 > 35mm

Question 33

LVH can be diagnosed if the R wave in ____ is > ____

Answer 33

R wave in aVL is > 11mm

Question 34

LVH can be diagnosed if the R wave in _____ + the S wave in ______ are > _____

Answer 34

R in Lead I + S in Lead III > 25mm

Question 35

RAD can indicate what chamber abnormality?

Answer 35

RVH

Question 36

LAD can indicate what chamber abnormality?

Answer 36

LVH

Question 37

R wave > S wave in V1 indicates...

Answer 37

RVH

Question 38

S wave > R wave in V6 indicates...

Answer 38

RVH

Question 39

Downward progressing R waves from V1-V5 indicates...

Answer 39

RVH

Question 40

very large R waves in lateral leads (V4, V5, V6) can indicate

Answer 40

LVH