Chapter 8: Rhythm Recognition

Question 1

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

Answer 1

Anterior posterior positions

Permanent pace maker in right pectoral region
Chest wall trauma

Question 2

What is the normal length of a PR interval?

Answer 2

3-5 small squares

0.12-0.20s

Question 3

What is the normal length of a QRS?

Answer 3

<3 small squares

<0.12s

Question 4

What happens to the QRS in a bundle branch block?

Answer 4

Widens

Question 5

How can VF be classified?

Answer 5

Fine or Coarse - depending on amplitude of complexes

Question 6

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

Answer 6

Ectopic beats

Question 7

Describe how atrial flutter may be seen?

Answer 7

Regular repetitive positive deflection with a saw tooth appearance

Often around 300 beats/min

Usually in inferior leads - II, III, AVF

Can be 2:1, 3:1 etc.

Question 8

How may retrograde atrial activation be spotted?

Answer 8

Inverted p waves in II and aVF

Question 9

What is the immediate treatment for polymorphic VT?

Answer 9

Same as for VF:

• shock
• adrenaline every 3-5 mins
• amiodarone after 3rd shock

Question 10

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

Answer 10

Start of Q to end of T

It is corrected to calculate QTc = QT/square root of RR

Should be >0.35s and <0.44s in males, <0.46s in females

Use QT segment in II lead - most accurate

Question 11

What can cause long QT?

Answer 11

Hypokalaemia
Hypomagnasaemia
Amiodarone (avoid in pt. with Torsades)
Hypocalcaemia
Hypothermia

Meds - amitriptyline 

Question 12

What are some reversible causes for PEA?

Answer 12

Severe fluid depletion or blood loss
Cardiac tamponade
Massive PE
Tension pneumothorax

Question 13

What are the main causes for Bradyarrhythmias?

Answer 13

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

Question 14

When does axonal rhythm occur and what is it?

Answer 14

Occur in dying patients

Slow irregular wide ventricular complexes

Does;t usually generate pulse

Often progress to asystole

Question 15

How can tachyarrhythmia’s be split up?

Answer 15

Narrow complex - SVT - atrial flutter/AF

Broad complex - VF/VT (can be SVT + AV block but less common)

Question 16

How does adenosine administration look at ecg

Answer 16

SVT then goes into wavy fine line then into sinus rhythm

Question 17

How does bundle branch block work

Answer 17

Makes QRS a W or M due to one branch of the purkinjie fibres being damaged and thus delayed compared to the other, making the ECG QRS that shape.

Question 18

ECG shows VF in a concious patient, what do you do

Answer 18

Unlikely to be true VF unless they become unconscious, more likely to be artefact

Question 19

Other broad complex tachycardias not related to VT

Answer 19

Accessory pathways from atria - WPW syndrome going into AF

Question 20

How is VT with a pulse treated

Answer 20

Amiodarone 300mg 10-60 mins

3 DC shocks under GA if fail

Question 21

Causes of shortened QT

Answer 21

Hypercalcaemia
Digoxin

Question 22

Look in book at various rhythms

Answer 22

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