ECG Signs, Scores, Tips, Tricks

Question 1

ECG in Pericarditis

Answer 1

ECG in Pericarditis
= PR depression (Spodeck Sign)
= Concave ST elevation global
= Sinus tachycardia
= AFib, Flutter, APC’s

Question 2

ECG on paper analysis

Answer 2

The rate of paper (i.e. of recording of the EKG) is 25 mV/s which results in:

1 mm = 0.04 sec (or each individual block)
5 mm = 0.2 sec (or between 2 dark vertical lines)
Distance between Tick marks = 3 seconds (in the rhythm strip)
The voltage recorded from the leads is also standardized on the paper where 1 mm = 1 mV (or between each individual block vertically) This results in:

1 mm = 0.1 mV
5 mm = 0.5 mV (or between 2 dark horizontal lines)
10 mm = 1.0 mV

Question 3

ECG in pulmonary embolism
Various Presentation

Answer 3

Sinus tachycardia most common
Tall R in V1
RV strain -
= ST down T down in V1V2V3
= ST down T down in II/ III/ aVF
Right BBB
T inversions in V1V2V3
S1S2S3 - deep S in 1/2/3 leads
S1Q3T3 - deep S1, Q in 3, T inv in 3
Inferior STEMI - rarely

Question 4

ECG in Dextrocardia

Answer 4

= Right axis deviation
= Positive QRS complexes (with upright P and T waves) in aVR
= Lead I: inversion of all complexes, aka ‘global negativity’ (inverted P wave, negative QRS, inverted T wave)
= Absent R-wave progression in the chest leads (dominant S waves throughout)

= Normal life exceptancy if no other abnormalities and equal frequency in Male:females
Associations:
= Kartagener syndrome with situs inversus + bronchiectasis + recurrent sinusitis + dextrocardia

Question 5

STE in lead aVR

Answer 5

1. Left main obstruction 2. Acute pericarditis 3. TCA poisoning 4. AVRT

Question 6

STE in aVR - mechanism

Answer 6

Question 7

STE in aVR - Causes

Answer 7

Question 8

STE in aVR- Example 2

Answer 8

Question 9

STE in aVR- Example 3

Answer 9

Question 10

STE in aVR- Example 4

Answer 10

Question 11

STE in aVR- Example 5

Answer 11

Question 12

STE in aVR- Example 6

Answer 12

Question 13

STE in aVR- Example 7

Answer 13

Question 14

STE in aVR- Example 8

Answer 14

Question 15

Broad complex tachycardia with RBBB criteria’s

Answer 15

Lead V1:
- rSR’ with R’ > r
- RS with R > S

Lead V6:
- if a Q wave is present - it must be 40 ms and < 0.2 mV

Question 16

Broad complex tachycardia with LBBB criteria’s

Answer 16

Lead V1:
- rS or QS with time to S wave nadir is < 70 ms

Lead V6:
- R wave with no Q wave

Question 17

Tachyarrhythmia likely VTach

Answer 17

• broad QRS > 140 ms or 3.5 small squares
• markedly negative LAD
• < 40 ms R-R variation
• QRS concordance in chest leads is mainly positive side
• capture beats
• known CAF or poor LVEF

Question 18

Irregular Broad Tachycardia

Answer 18

Atrial fibrillation with aberration
Atrial flutter with aberration
Multifocal atrial tachycardia with BBB
Pre-excited AF (WPW)
Torsade de pointes

Question 19

Monomorphic Ventricular Tachycardia

Answer 19

Precordial thump
Unsynchronised cardioversion 200 J
If stable -
- IV Amiodarone or
- IV Sotalol or
- IV Procainamide
- Lidocaine or beta blockers 2nd line

• IV Magnesium 8 mmols over 5 min followed by 60 mmols in 50 ml glucose over 24 Hrs if at risk of low Mg (on diuretics, alcoholics)

Think of need for PCI
- correct UE and acidosis

Question 20

Brugada syndrome

Answer 20

ST elevation in V1-V3
ST elevation might need a trigger as fever

RBBB
Sudden death
Autosomal dominant, SCN5a mutation

Diagnostic test - additional 1mm STE in V1-V3 after iv Flecainide 2mg/kg or Procainamide 10 mg/kg in 10 minutes

Question 21

QTc formulas

Answer 21

Question 22

QTc nomogram

Answer 22

Question 23

LVH criteria

Answer 23

LVH: Voltage criteria:

• tallest R (v4-v6) + deepest S (v1-v3) > 40
• tallest R (v4-v6) > 27 mm
• deepest S (v1-v3) > 30 mm
• R in aVL > 13 mm
• QRS > 0.08
• abnormal ST depression or T inversion in V4-V6

Question 24

Limb leads

Answer 24

Lead I: negative right arm, positive left arm

Lead II: negative right arm, positive left leg

Lead III: negative left arm, positive left leg

All axis forms an equilateral triangle called Einthoven’s triangle.

Question 25

Augmented leads

Answer 25

All unipolar leads are termed V leads and includes augmented & precordial leads.

aVR - faces heart from heart shoulder
aVF - faces heart from left foot
aVL - faces heart from left arm