Part A - ECG

Question 1

What is important to remember about a hypoxic pt who requires salbutamol?

Answer 1

Hypoxic pt tends to have a HR of 200+ as a drop in I2 can increase HR
Salbutamol is a synthetic version of adrenaline which will also increase their HR

Question 2

What rhythm has a rate of 60/70 bpm, irregularly regular, increases on inspiration and decreases on expiration?

Answer 2

Sinus arrhythmia

Question 3

Which pt commonly get sinus arrhythmia?

Answer 3

During sleep
Young pt
Athletes

Question 4

What rhythm has a PR interval, present P wave and narrow needle like QRS?

Answer 4

Rapid tachycardia

Question 5

What does a narrow complex mean?

Answer 5

Both bundle branches depolarise together and impulses come from above the division of the bundle of His

Question 6

What rhythm rarely has a QRS, more of a RS wave?

Answer 6

Broad ventricular complex

Question 7

What are the 3 causes of broad ventricular complex?

Answer 7

1. Ventricular ectopic (e.g. VT, broader than BBB, 140 bpm, impulse starts in the ventricle so conduction speed is slower as one side is not rapidly depolarising)
2. BBB (breadth of complex with sinus beat)
3. Ventricular pacemaker (pacemaker in BB, rate is slowest)

Question 8

What rhythm has a broad complex at 140+ bpm and no PR ratio?

Answer 8

Ventricular tachycardia

Question 9

What are the main causes of ectopic formation?

Answer 9

1. Ischaemic formation
2. Electrolyte imbalance
3. Fibrosis in the heart
4. Abnormal stretch
   Any 3 of these increases the chance of ectopic formation

Question 10

What causes abnormal stretch?

Answer 10

Ion channels are abnormally stretched due to high blood pressure, causing too much calcium to enter into the cell. This causes contraction before the SA node fires causing an ectopic beat. (Important for AF)

Question 11

What are the 3 causes of left atrial stretch? (Main reason for AF)

Answer 11

1. Mitral valve regurge (camel hump P wave)
2. Poorly controlled hypertension
3. Heart muscle degenerates with age = slack and more fatty muscle causing blood to regurge into the pulmonary vein, leading to a pulmonary oedema

Question 12

How do you treat sinus tachycardia?

Answer 12

Treat the cause of the arrhythmia

Don’t defibrillate or cardiovert

Question 13

What are the causes of 1st degree AV block?

Answer 13

Problem with the AV node
Overt parasympathetic tone
Beta blockade
Too much vagal tone
Ischaemia

Question 14

What happens to a pt with 1st degree AV block?

Answer 14

Tens to stay the same or get better

Can lead to full blockage

Question 15

What is the cause for 3rd degree AV block?

Answer 15

AV node has been destroyed so a ventricle pacemaker kicks in, leading to multiple P waves

Question 16

What rhythm has a constant PR interval pattern, >1:1 PR ratio, broad complex, regular or irregular

Answer 16

2nd degree type 2 AV block

Question 17

What is the cause of 2nd degree type 2 AV block?

Answer 17

AV block gets worse leading to a standstill = constant P wave and lower ventricular pacemaker
Ventricular complex normally broad = BBB due to ischemia of the septum

Question 18

What rhythm has a prolonged PR interval which gradually increases each time until a ventricular beat is dropped and always has 1 less ventricular complex to P waves?

Answer 18

2nd degree type 1 AV block

Question 19

What is the digoxin effect?

Answer 19

1. Slows - brings heart rate to 60 bpm
2. Steadies - steadies AF rhythm
3. Strengthens
   Shown through a inverted T wave