Chapter 8: Rhythm Recognition

Question 1

What is the typical position for the defibrillator pads?

Answer 1

1. Beneath right clavicle
2. Left MAL

Question 2

What alternative position for defibrillator pads can be used and when?

Answer 2

Position:
1. Anterior posterior positions

When:
1. Permanent pace maker in right pectoral region
2. Chest wall trauma

Question 3

What is the normal length of a PR interval?

Answer 3

1. 3-5 small squares
2. 0.12-0.20s

Question 4

What is the normal length of a QRS?

Answer 4

1. < 3 small squares
2. < 0.12 s

If QRS < 0.12s- originates above Bundle of His
If QRS > 0.12s - orginates from ventricles or supraventricular rhythm w/ BBB

Question 5

What happens to the QRS in a bundle branch block?

Answer 5

Widens

Question 6

How can VF be classified?

Answer 6

Fine or Coarse - depending on amplitude of complexes

Question 7

What is likely the diagnosis if there is a regular rhythm with intermittent irregularity?

Answer 7

Ectopic beats

Question 8

Describe how atrial flutter may be seen?

Answer 8

1. Regular repetitive positive deflection
2. With a saw tooth appearance
3. Often around 300 beats/min
4. Usually in inferior leads - II, III, AVF
5. Can be 2:1, 3:1 etc.

Question 9

How may retrograde atrial activation be spotted?

Answer 9

1. Inverted p waves
2. In II and aVF

Question 10

What is the immediate treatment for polymorphic VT?

Answer 10

Same as for VF:

1. Shock
2. Adrenaline every 3-5 mins
3. Amiodarone after 3rd shock

Question 11

What is the normal QT interval and how is it measured??

Answer 11

1. Start of Q to end of T
2. It is corrected to calculate QTc = QT/square root of RR
3. Should be >0.35s and <0.44s in males, <0.46s in females

Question 12

What can cause long QT?

Answer 12

1. Hypokalaemia
2. Hypomagnasaemia
3. Amiodarone (avoid in pt. with Torsades)
4. Hypocalcaemia
5. Hypothermia

Question 13

What are some reversible causes for PEA?

Answer 13

1. Severe fluid depletion or blood loss
2. Cardiac tamponade
3. Massive PE
4. Tension pneumothorax

Question 14

What are the main causes for Bradyarrhythmias?

Answer 14

1. Heart block - 1st, 2nd Mobitz I and II, 3rd
2. Escape rhythm’s - SA node fail
3. Agonal rhythm’s

Question 15

When does agonal rhythm occur and what is it?

Answer 15

1. Occur in dying patients
2. Slow irregular wide ventricular complexes
3. Doesn’t usually generate pulse
4. Often progress to asystole

Question 16

How can tachyarrhythmia’s be split up?

Answer 16

1. Narrow complex - SVT / atrial flutter / AF
2. Broad complex - VF/VT (can be SVT + AV block but less common)

Question 17

6 stage system to analyse rhythm:

Answer 17

1. Is there electrical activity?
2. What is the rate?
3. What is the rhythm - regular or irregular?
4. Is the QRS complex narrow or broad?
5. Is atrial activity present?
6. Is atrial activity related to ventricular activity?

Question 18

What to check if no eletrical activity?

Answer 18

1. Check gain control
2. Check electrode connections
3. Check pulse

Question 19

What does a completely flat line on ECG usually mean?

Answer 19

1. Lead not connected

Question 20

What is an ECG with atrial activity but NO QRS complexes?

Answer 20

1. Ventricular standstill

Question 21

Mx of ventricular standstill?

Answer 21

1. Pacing

Question 22

ECG appears to be VF but pt. conscious - what could be cause?

Answer 22

1. Likely artefact

Question 23

How is VF classified?

Answer 23

1. Classified according to amplitude of complexes
2. Coarse vs Fine

Question 24

How to calculate rate?

Answer 24

1. Count number of R-Rs
2. In 30 large squares (6s)
3. Multiply by 10

In 15 large squares (3s)
Multiply by 20

Question 25

How to classify irregular rhythms?

Answer 25

1. Totally **irregular** 2. **Basic** regular rhythm w/ **intermittent irregularity** 3. **Recurring cyclic** variability

Question 26

If R-R intervals are totally irregular and QRS complex of constant morphology - what is the most likely rhythm?

Answer 26

1. **AF**

Question 27

If the QRS complex is narrow (<0.12s) the beat is likely to come from?

Answer 27

1. **Above** the **ventricular** myocardium ## Footnote From Atrial mm. or AV node

Question 28

Broad complex ectopic beats may originate from where?

Answer 28

1. **Ventricular** origin 2. **Supraventricular** ectopic beats w/ **BBB**

Question 29

What is an escape beat?

Answer 29

1. Beat **originating** in **AV node** or **ventricular myocardium** 2. After a **long pause** ## Footnote AV node or ventricle is acting as back up pacemaker

Question 30

Best leads to see AF?

Answer 30

1. **Lead II** 2. **V1**