ECG Interpretation

Question 1

ECG definition of a STEMI

Answer 1

Men
1. 2.5 small square rise in ST in V2 - 3 (2 squares if over 40 y/o)

Women
2. 1.5 small squares in V2 - 3

3. 1 square in any other leads
4. must be 2 consecutive leads

5.New LBBB

Question 2

Pericarditis (3)

Answer 2

1. Widespread ST elevation
2. Saddle-shaped ST
3. PR depression - most specific

Question 3

Atrial Flutter (2)

Answer 3

1. Sawtooth Baseline (rapid successive P waves)
2. Ventricular rate depending on degree of AV Node Block

Question 4

Brugada Syndrome

Answer 4

1. J point Elevation in V1-3
2. Convex ST elevation
3. Inverted T waves

Question 5

Left Ventricular Hypertrophy (2)

Answer 5

1. Sum of S wave in V1 and R wave in V5 or 6
2. Exceeds 40mm - 8 big squares

Question 6

Left Atrial Enlargement (3)

Answer 6

1. Bifid P Wave in lead 2 with duration
2. > 120 ms - 3 little sqaures
3. In V1 P wave is Terminal Negative (last portion is negative deflection)

Question 7

Causes of Left Axis Deviation (7)

Answer 7

1. Left anterior Hemiblock
2. LBBB
3. Inferior MI
4. WPW syndrome - Right sided accessory pathway
5. Hyperkalaemia
6. Congenital - Ostium Primum ASD, Tricuspid Atresia
7. Minor in Obese people

TEST ANSWER IF NOT SPECIFIED - WPW SYNDROME

Question 8

Causes of Right Axis Deviation (9)

Answer 8

1. RVH
2. Left Posterior Hemiblock
3. Lateral MI
4. Chronic Lung Disease - Cor Pulmonale
5. PE
6. Ostium Secundum ASD
7. WPW Syndromre with Left Accessory Pathway
8. Normal Infant <1
9. Minor in Tall People

TEST ANSWER IF NOT SPECIFIED = WPW Syndrome

Question 9

Define Bifasicular Block (2)

Answer 9

1. Combined RBBB with either Anteriror or Posterior left fascicle also blocked
2. Causes RBBB with Left Axis Deviation

Question 10

Define Trifasicular Block (2)

Answer 10

1. Combination of Bifasicular block and an AVN block above it like a 1st or 2nd degree
2. Results in RBB with LAD AND a prolonged PR interval or 2nd degree signs

Its a Misnomer - it is NOT a complete hearet block like it sounds

Question 11

Which Leads pertain to the Left Anterior Descending Artery (1)

Answer 11

1. ANTEROSEPTAL LEADS - V1 - V4

Question 12

Which Leads pertain to the Richt Coronary Artery (3)

Answer 12

1. INFERIOR LEADS - 2, 3, aVF

Question 13

Which Leads pertain to the Proximal Left Anterior Descending Artery (1)

Answer 13

1. ANTEROLATERAL LEADS - V1-6, aVL

Question 14

Which Leads pertain to the Left Circumflex Artery (1)

Answer 14

1. LATERAL LEADS - 1, aVL, V5-6

Question 15

Which Leads pertain to the Left Cirumclex/Right Coronary Artery (1)

Answer 15

1. V1-3 +/- POSTERIOR LEADS placed on back to confirm V7-9

Question 16

Sign of new ACS on ECG (1)

Answer 16

1. New LBBB

Question 17

Signs of Digoxin on ECG (4)

Answer 17

1. Down-Sloping ST depression “Reverse Tick”
2. Flatened / Inverted T waves
3. Short QTc
4. Arrhythmias - AV Block, Bradycardia

Question 18

Signs of Hypokalaemia on ECG (5)

Answer 18

1. U waves
2. Small or absent T waves (opposite to hyperK)
3. Prolonged PR
4. ST Depression
5. Long QTc

“U have no Pot and no T, but a long PR and a long QTc”

Question 19

Signs of Hypothermia on ECG (5)

Answer 19

1. Brodycardia
2. J waves - Osborne Waves = small bump at end of QRS
3. 1st deg Heart block - long PR
4. Long QTc
5. Arrhythmias

Question 20

Signs of LBBB on ECG (4)

Answer 20

1. WiLLiaM
2. V1- rS - basically a single negative deflection in V1 with a small upstroke first (the little r and big S)
3. V6 - R - M shaped / notched R wave in V6
4. Wide QRS

Question 21

Causes of LBBB (5)

Answer 21

1. MI
2. HTN
3. AS
4. Cardiomyopathy
5. Fibrosis

NEW LBB IS ALWAYS PATHOLOGICAL

Question 22

Sign onECG of previous infarction (1)

Answer 22

1. Pathological Q waves

Question 23

Describe ECG changes seen in MI in a temporal order (what comes first etc) (4)

Answer 23

1. First sign is Hyper Acute T waves meaning - broad, asymmetrically peaked T waves
2. ST elevation follows
3. T wave inversion next within 24 hours and resolve between days and months
4. Pathological Q waves which remain permenantly

Question 24

Normal ECG changes in an Athlete (4)

Answer 24

1. Sinus brady
2. Junctional rhythms
3. 1st Deg AVN block
4. Mobitz 1 - Wenckebach

Question 25

P wave changed and Dxs on ECG (3)

Answer 25

1. Increased P wave Amplitude is called P Pulmonale and is a sign of = Cor Pulmonale - which is pulmonary hypertension stressing the right heart 2. Broad, notched, bifid P waves = often best seen in Lead II, Left Atrial enlargement = Mitral Stenosis 3. Absence of P = AFib

Question 26

Causes of prolonged PR interval (9)

Answer 26

1. Idiopathic 2. IHD 3. Digoxin toxicity 4. Hypokalaemia 5. Aortic root disease secondary to IE 6. Lyme disease 7. Sarcoidosis 8. Myotonic Dystrophy 9. Athletes

Question 27

Causes of Short PR interval (1)

Answer 27

1. WPW Syndrome

Question 28

Signs of RBBB on ECG (4)

Answer 28

1. MaRRoW 2. V1 - rSR' - means a small deflection up (r) then large down (S) then second large up (R') - creating the M shape in V1 andnis caused by the delayed right vent depolarising (the 2nd large R wave) 3. V6 - qRs - (really small downard q, then large positive R, then slurred/notched S wave that slowly rejoins iso line) The S wave is the bit considered to look like a W as it slurrs to the electric line. 4. Broad QRS

Question 29

Causes of RBBB (7)

Answer 29

1. Normal Variant in increasing age 2. RVH 3. Chronic increase RV pressure - Cor Pulmonary 4. PE 5. MI 6. ASD - Ostium Secundum 7. Cardiomyopathy or myocarditis

Question 30

Causes of ST depression (5)

Answer 30

1. Secondary to abnormal QRS (LVH, LBBB, RBBB) 2. Ischaemia 3. Digoxin 4. Hypokalaemia 5. Syndrome X

Question 31

Causes of ST Elevation (7)

Answer 31

1. MI 2. Pericarditis / myocarditis 3. Normal Variant - "high take off" 4. LV aneurism (following serious transmural ischaemia / death) 5. Prinzmetal's Angina (coronary spasm) 6. Takotsubo Cardiomyopathy (broken heart syndrome from severe meotional distress - think death of partner) 7. SAH - rare

Question 32

Causes of Peaked T Waves (2)

Answer 32

1. HypERkalaemia 2. Myocardial Ischaemia - acute phase of MI

Question 33

Causes of Inverted T waves (6)

Answer 33

1. Myocardial Ischamia - later sign in STEMI 2. Digoxin Toxicity 3. SAH 4. ARVH 5. PE (s1q3 "T3" - means T inversion) 6. Brugada Syndrome

Question 34

Wellen's Syndrome on ECG (4)

Answer 34

1. A pattern seen in significant LAD stenosis 2. Biphasic or Deep T wave inversion in V2 and V3 3. Minimal ST elevation 4. No Q Waves

Question 35

Effect of Hypercalcaemia on QTc (1)

Answer 35

1. Shortens QTc

Question 36

HOCM (4)

Answer 36

1. LVH 2. Non specific ST and T changes 3. Deep Q waves 4. AFib occaisionally

Question 37

WPW Syndrome (4)

Answer 37

1. Short PR inteval 2. Wide QRS with Slurred upstroke (delta waves) 3. Left Axis Deviation if right sided accessory pathway - most cases and most Questions (TYPE B) 4. Right Axis Deviation if Left sided accessory pathway (TYPE A)

Question 38

Normal QRS duration? (1)

Answer 38

1. 80 - 100 ms (0.08 -0/1 seconds)