QRS and Abnormalities

Question 1

DDX of Wide QRS

Answer 1

BBB

Hyperkalemia

V-tach

WPW

Paced rhythm

MEDS (esp TCA antidepressants)

Question 2

What is this? Describe it.

What other leads can you see this in?

Answer 2

LBBB

V₁ - V₂ deep S-wave

V₅ - V₆ have M shape

Question 3

What is this? Describe it.

What other leads can you see this in?

Answer 3

LBBB

V₁ - V₂ R-S-R pattern (DEEP M-shape)

V₅ - V₆ wide S-wave

Question 4

Q-waves should never be present in ___

Answer 4

V₁ - V₃

Question 5

Pathological Q-wave is defined as one of these 3 criteria

Answer 5

> 0.04 secs WIDE

> 2 mm DEEP

> 25% of QRS complex

Question 6

DDX of pathological q-wave

Answer 6

MI (old or new)

PE

LBBB

LVH

Question 7

Low voltage QRS

Leads ___ ≤ ___ mm

or

Leads ___ ≤ ___ mm

Answer 7

I + II + III ≤ 15 mm

V₁ + V₂ + V₃ ≤ 30 mm

Question 8

DDX of low voltage QRS

(Think: something is blocking the conduction)

Answer 8

Pericardial effusion (esp if tachy + SOB)

Obesity

COPD

Heart Failure

(Infiltrated diseases - RARE)

Question 9

Expected R-wave progression

DDX for poor R-wave progression?

Answer 9

R-wave should progressively increase from V₁ - V₆

DDX: Anterior MI, RVH w/ strain

Question 10

Dominant R-wave

DDX?

Answer 10

R-waves > S-waves in V₁ - V₃

DDX: Posterior MI, RBBB, RVH

Question 11

What is this? What is the voltage rule?

Answer 11

LVH

R-wave in V5 or V6 + S-wave in V1 or V2

> 35 mm

Question 12

What is the implication of V₁ and V₆ here? What is the rule?

Answer 12

RVH

R-wave in V1 or V2 + S-wave in V5 or V6

> 10 mm

+ Right axis deviation increases likelihood