ECG quiz

Question 1

LPFB

Answer 1

Right axis deviation (> +90 degrees)
Small R waves with deep S waves (= ‘rS complexes’) in leads I and aVL
Small Q waves with tall R waves (= ‘qR complexes’) in leads II, III and aVF
QRS duration normal or slightly prolonged (80-110ms)
Prolonged R wave peak time in aVF
Increased QRS voltage in the limb leads
No evidence of right ventricular hypertrophy
No evidence of any other cause for right axis deviation

*Hardly ever seen in isolation. Usually with RBBB

Question 2

LAFB

Answer 2

Left axis deviation (usually between -45 and -90 degrees)
Small Q waves with tall R waves (= ‘qR complexes’) in leads I and aVL
Small R waves with deep S waves (= ‘rS complexes’) in leads II, III, aVF
QRS duration normal or slightly prolonged (80-110 ms)
Prolonged R wave peak time in aVL > 45 ms
Increased QRS voltage in the limb leads

Question 3

LV strain pattern

Answer 3

ST segment depression and T wave inversion in the left-sided leads

Question 4

Bifascicular block

Answer 4

Combination of RBBB with either LAFB or LPFB

a sign of extensive conducting system disease, although the risk of progressing to complete heart block is thought to be relatively low (1% per year in one cohort study of 554 patients)

Question 5

LVH criteria

Answer 5

Sokolov-Lyon criteria (S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm)

MUST also have non-voltage criteria to be considered LVH

• Increased R wave peak time > 50 ms in leads V5 or V6
• ST segment depression and T wave inversion in the left-sided leads: AKA the left ventricular ‘strain’ pattern

Question 6

RV strain pattern

Answer 6

ST depression and T wave inversion in the leads corresponding to the right ventricle:

• The right precordial leads: V1-3, often extending out to V4
• The inferior leads: II, III, aVF, often most pronounced in lead III as this is the most rightward-facing lead.

Question 7

Causes of right ventricular strain

Answer 7

Pulmonary hypertension
Mitral stenosis
Pulmonary embolism
Chronic lung disease (cor pulmonale)
Congenital heart disease (e.g. Tetralogy of Fallot, pulmonary stenosis)
Arrhythmogenic right ventricular cardiomyopathy

Question 8

Incomplete trifascicular block

Answer 8

Fixed block of two fascicles (i.e. bifascicular block) with evidence of delayed conduction in the remaining fascicle (i.e. 1st or 2nd degree AV block).

OR

Fixed block of one fascicle (i.e. RBBB) with intermittent failure of the other two fascicles (i.e. alternating LAFB / LPFB).

Asymptomatic bifascicular block with first degree AV block is not an indication for pacing

Question 9

Complete trifascicular block

Answer 9

Bifascicular block + 3rd degree AV block

Question 10

Which biomarker rises first after AMI?

Answer 10

Myoglobin!

CKMB up after 2-6 hours and normal after 2-3 days
Trop T up at 4-6 hours and elevated for up to 10 days

Question 11

Inheritance pattern for Catecholaminergic polymorphic VT

Answer 11

Autosomal dominant

Question 12

Clinical findings in HOCM?

Answer 12

jerky pulse, large ‘a’ waves, double apex beat

ejection systolic murmur: increases with Valsalva manoeuvre and decreases on squatting

Question 13

HOCM echo findings (mnemonic MR SAM ASH)

Answer 13

Mitral regurg
Systolic anterior motion of anterior MV leaflet
Asymetrical hypertrophy

Question 14

L axis deviation causes

Answer 14

L anterior hemiblock
L BBB
WPW with R sided accessory pathway
Hyperkalaemia
congenital: ostium primum ASD, tricuspid atresia
Minor LAD in obese people

Question 15

Causes of R axis deviation

Answer 15

RVH
L posterior hemoblock
Chronic lung disease-->cor pulmonale
PE
Ostium secundum ASD
WPW with L sided accessory pathway 
Infant under 1 year
Minor RAD in tall people

Question 16

What are some things that can cause digoxin toxicity?

Answer 16

Classically: hypokalaemia
Increasing age
Renal failure
Myocardial ischaemia
Low Mg
High Ca, Na, acid
Hypoalbuminaemia
Hypothermia
Drugs: amiodarone, verapamil, diltiazem, spironolactone (competes for DCT excretion), cyclosporine, loop and thiazides due to K effect

Question 17

Causes of long PR

Answer 17

Idiopathic
IHD
Aortic root abscess in pericarditis
Rheumatic fever
Hypokalaemia
Dig toxicity
Sarcoid
Myotonic dystrophy

Question 18

ECG features digoxin

Answer 18

Short QT
Down sloping ST depression (reverse tick)
Flat/inverted T waves
Arrhythmias like AV block, bradycardia

Question 19

Hypokalaemia on the ECG

5

Answer 19

Prominent P waves
U waves
long PR
ST depression
Apparent long QT interval due to fusion of the T and U waves (= long QU interval)
small or absent T waves (earliest change)
Ectopics

Question 20

LAD

Answer 20

left anterior hemiblock
left bundle branch block
Wolff-Parkinson-White syndrome* - right-sided accessory pathway
hyperkalaemia
congenital: ostium primum ASD, tricuspid atresia
minor LAD in obese people

Question 21

RAD

Answer 21

right ventricular hypertrophy
left posterior hemiblock
chronic lung disease → cor pulmonale
pulmonary embolism
ostium secundum ASD
Wolff-Parkinson-White syndrome* - left-sided accessory pathway
normal in infant

Question 22

Cannon A waves causes

Answer 22

regular- AVNRT

irreg- CHB

Question 23

What is the treatment for multifocal atrial tachycardia?

Answer 23

A rate limiting calc blocker is first line!