Hypertrophy

Question 1

Hypertrophy vs enlargement and what we use to refer to these

Answer 1

Hypertrophy = (ventricles, thicken), which is why size is effected
Enlargement = Atria (stretch out) - which is why time is effected

Question 2

What are the types of hypertrophy vs enlargement

Answer 2

RAE
LAE
RVH
LVH

atria = enlargement
ventricle = hypertrophy

Question 3

What is a normal P wave?

Answer 3

< 0.12 seconds (3 boxes)
<2.5 mm (2.5 boxes atrial activity is pretty small)

short and small

Question 4

What leads are good indicators of a normal P waves?

Answer 4

Lead II (right at the mean vector)
Lead V1 (biphasic, because right atrium is towards it while left atrium is away from it)

Deviation from these

Question 5

What would happen if a right atrium is larger in a P wave and why?

Answer 5

The first part of the p wave is indicative of the electricity from the right atrium, so it will NOT effect the time, but would rather effect the height of the p wave.

best visualized in lead II and V1

Question 6

What is the criteria of RAE and rationale?

Answer 6

Leads to heightened amplitude of P wave > 2.5 mm (2.5 boxes in 1 inferior lead (II, III, aVF)

Just need 1 inferior lead!

Rationale: takes more voltage to depolarize a bigger right atrium

Question 7

What does a lead VI look like in RAE?

Answer 7

First part of p wave is heightened, but negative deflection is normal

Because right atrium is affected NOT the left

Question 8

What does a left atrial enlargement lead to?

Answer 8

A prolonged p wave that may be notched. It affects time and NOT amplitude because it takes longer to depolarize the left atrium.

Question 9

What does lead VI look like in LAE?

Answer 9

Normal positive deflection with a prolonged negative deflection.

Because left atrium is affected NOT the right

Question 10

What is the criteria for LAE?

Answer 10

Criteria:
P wave > 0.12 sec (3 boxes) w/ terminal portion > 0.04 sec (1 box, which is where it is notched)

Terminal portion of P wave in V1 > 1 mm below (negative

Question 11

Can you have biatrial enlargement?

Answer 11

Yes, but must meet both criteria

Question 12

What is a normal QRS net vector?

Answer 12

Down and to the left in the axis between 0 and 90 (4th quadrant)

Question 13

What happens to the QRS segment in the pericordial leads as you go from V1 –> V6

Answer 13

Start mostly negative deflection at V1 and progresses to mostly positive at V6

R waves start small at v1 (because the lead is closer to the right ventricle, which does not depolarize as much) and increase at v6 (which is closer to the left ventricle, which depolarizes the most)

S wave = opposite

v1 and v2 tells us the most about the RV
v4 is the transition point
v5 and v6 tells you the most about the

Question 14

What happens with RVH limb leads?

Answer 14

1. Right axis deviation (NEEDED) negative QRS in lead 1 and aVL and positive QRS in aVF (this is because the vector is pointing AWAY and to the right instead of the left)

If you see right axis deviation, it is VERY likely this

Question 15

What happens with RVH chest leads?

Answer 15

Instead of R wave progression, it is OPPOSITE, because it is pointing to the right instead (pointing towards limb lead 1)

Starts with big R positive wave at lead 1 and then small R wave at 6

Question 16

What happens with LVH in chest leads?

Answer 16

Larger amplitude of R wave

Question 17

Do you need to have EKG abnormalities for LVH?

Answer 17

NO, there can be other conditions that mask it
e.g. chest wall hypertrophy that masks the electricity

meeting the criteria though is HIGHLY suggestive of LVH
sensitive but not specific

Question 18

What is the limb lead criteria for LVH? Which lead do we look at?

Answer 18

Limb Lead Criteria:
The R-wave amplitude in lead aVL exceeds 11 mm (11 boxes) (lead 1 will be increased as well)

same vector as normal (because it is typically is the whole LV) just larger

Left axis deviation

Question 19

What is the chest lead criteria for LVH?

Answer 19

Chest Lead Criteria:
The R-wave amplitude in lead V5 or V6(positive) plusthe S wave amplitude in lead V1 or V2 (negative) exceeds 35 mm

Question 20

What is the combined criteria for LVH that is used to make sure there is not displacement?

Answer 20

The R-wave amplitude in aVL plus the S-wave amplitude in V3 exceeds 20 in women and 28 in men

The more criteria they meet, the more likely they have LVH

Don’t need to memorize this

Question 21

What are downfalls of ventricular hypertrophy criteria?

Answer 21

Not accurate in <35 yo (because some have stronger hearts)
If there is LVH with repolarization then there is concern and you should get an echo

Question 22

Does ventricular hypertrophy effect amplitude, timing, or both?

Answer 22

Only amplitude (still fast)

Question 23

What are secondary repolarization abnormalities d/t ventricular hypertrophy?

Answer 23

Can lead to downsloping (linear) ST segment depression
T-wave inversion

seen in both right (V1 V2) and left (lead 1 AVL, V5, V6)

This can cause false readings for ischemia