Complete Heart Block

Question 1

What is a complete heart block?

Answer 1

Failure of the AV node to transmit an electrical pulse causing the heart beat to be disrupted

Question 2

What are the structural abnormalities?

Answer 2

• Fibrosis of the AV node

- Necrosis/infarction of the AV node due to coronary artery disease)

Question 3

What happens in a complete heart block?

Answer 3

• Failure of the AV node to transmit an electrical impulse to the ventricle
• this causes the atria to contract independently of the ventricles
• the ventricles develop their own pacemaker activity

Question 4

What causes a complete heart block?

Answer 4

-taking a beta-blocker or other rate-lowering drugs, such as digoxin and verapamil, that act to block the AV node. These are most common in elederly people who previously has had a myocardial infarction

Question 5

What are the two types of complete heart block and how do they present?

Answer 5

• Chronic heart block, presents gradually and in isolation (tiredness and breathlessness with exercise)
• Acute heart block, presents suddenly with other symptoms (light headedness or collapse with loss of consciousness)

Question 6

What are the signs and symptoms of a complete heart block?

Answer 6

• tiredness and breathlessness with exercise (chronic complete heart block)
• light headedness or collapse with loss of consciousness (acute complete heart block)
• chest pain
• heart rate/pulse is slow (

Question 7

What are the abnormal test results?

Answer 7

?

Question 8

What is the medical/surgical intervention?

Answer 8

• the ambulance/paramedic staff may administer atropine

- a temporary pacemaker introduced immediately in hospital

Question 9

How does atropine work?

Answer 9

-it blocks the vagus nerve and acetylcholine allowing the heart rate to rise

Question 10

What is the secondary prevention?

Answer 10

-a permanent pacemaker if heart block persists after recovering from associated myocardial infarction an after stopping heart rate lowering drugs