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Flashcards in ECG- heart block Deck (13)
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1
Q

What is heart block?

A

Block in conduction between AV node and the ventricles causing a prolonged PR interval

2
Q

Types of heart block? (4)

A

First degree
Second degree Mobitz I
Second degree Mobitz II
Complete heart block

3
Q

What are the most common underlying cause of heart block? (2)

A

MI or ischaemic heart disease

Drugs e.g. beta blockers, calcium blockers

4
Q

How are Mobitz I and Mobitz II differentiated?

A

Mobitz I- progressive lengthening of PR interval until a beat is dropped.
Mobitz II- intermittent failure of conduction through the AV node (e.g. every three P waves)

5
Q

What defines third degree (complete) heart block?

A

No relationship between P waves and QRS complexes

6
Q

How is ventricular contraction caused in 3rd degree block and what is typically the rate?

A

Ventricular escape rhythm around 30-40bpm

7
Q

When is permanent pacemaker insertion recommended for heart block?

A

Symptomatic Mobitz I
Mobitz II
Complete heart block

8
Q

When is atropine used in heart block? How does it work?

A

In acute situations accompanied with clinical deterioration. Anti-muscarinic effect- increases the heart rate

9
Q

What are the two shockable cardiac arrest rhythms?

A

Pulseless ventricular tachycardia

V. Fibrillation

10
Q

What are the two non-shockable cardiac arrest rhythms?

A

Pulseless electrical activity

Asystole

11
Q

What are the reversible causes of cardiac arrest?

A
Hypoxia
Hypothermia
Hypovolaemia
Hypo/hyperkalaemia
Tamponade
Tension pneumothorax
Thromboembolisn
Toxins/metabolic
12
Q

When should adrenaline/amiodarone be given in cardiac arrest?

A

After the 3rd shock, then every 3-5 minutes afterwards (adrenaline only)

13
Q

When is adrenaline given for non-shockables?

A

Immediately, then every 3-5 minutes afterwards