EKG Basics

Question 1

5 Steps of Interpretation

Answer 1

1 - rate (300/150/100/75/60/50)

2 - rhythm (p b/f each QRS and QRS after ea p)

3 - axis (I and aVF)

4 - intervals, QRS < 120 and PR 120-200 and QT <440

5 - pathology (p wave size, QRS amp, ST elev, ST dep, T wave abnormalities, etc)

Question 2

EKG Evidence of Infarction

Answer 2

Peaked T waves (hyperacute - early hyperkalemia)

ST elevations > 1 mm above baseline (indicates transmural damage)

Q waves > 1 mm wide OR > 1/4 R height OR > 2 mm deep

New t wave inversion (pathological until proven otherwise - may be normal if isolated III or V1)

New LBBB (see sgarbossa criteria)

Question 3

Sgarbossa Criteria

Answer 3

Concordant ST elevation > 1 mm (+5)

Concordant ST depression > 1 mm in V1-V3 (+3)

Discordant ST elevation > 5 mm (+2)

**score of 3 or more is 90% specific

Question 4

WPW Findings

Answer 4

Dec PR interval

Wide QRS

Delta wave leading into QRS

Tx: ablation or anti-arrhythmia, no AV nodal blockade (adenosine)

Question 5

Brugada

Answer 5

Pseudo RBBB + ST elevation in V1-V2

Present w/ syncope

Type 1 - “coved” ST elevation > 2 mm w/ upward concavity and inverted t wave

Type 2 - “saddleback” elevated ST comes back to baseline then ascends again into upright or biphasic t wave

Question 6

Common QT Prolonging Drugs

Answer 6

A - anti Arrhythmia (amiodarone, sotalol, flecainide)
anti Addiction (methadone) 

B - anti Biotics (aminoglycosides, macrolides, fluoroquinolones)

C - anti psyChotics (haldol, quetiapine, risperidone)

D - anti-dep (SSRIs, TCAs)

E - anti-emetics (zofran, metoclopramide/Reglan)

Question 7

ARVD (5 EKG findings and tx)

Answer 7

Arrhythmogenic RV Dysplasia

• epsilon wave - small pos deflection at end of QRS, blip
• t wave inversion in V1-V3
• prolonged s wave upstroke in V1-V3
• QRS widening in V1-V3
• paroxysmal episodes of V tach w/ LBBB morphology

Tx - reduce anxiety and exercise, ICD, beta blockers

Question 8

Lead Distributions

Answer 8

I/ aVL/ V5-6 - lateral wall

II/III/aVF - inferior

V1-V2 - septal

Question 9

Pericarditis

Answer 9

diffuse ST elevation or PR depression

Question 10

Pericardial Effusion

Answer 10

diffusely low voltage

electrical alternans