Complete Heart Block

Question 1

What anatomical structures are affected?

Answer 1

AVN.

Caused by fibrosis of AVN or necrosis/infarction.

Question 2

How does this affect the heart?

Answer 2

AVN can’t release electrical impulses from atria to ventricles, so the two start contesting randomly and independently.

Heart block - atria and ventricles are divorced and are doing their own thing separately.

Question 3

What prior events cause this?

Answer 3

Being old.

Having a previous heart attack

Taking beta blockers or other rate lowering drugs (digoxin/verapamil) as these block the AVN

Question 4

Symptoms?

Answer 4

Tiredness

Breathlessness

Light headedness

Collapse/loss of concsiousness

Complete heart block can be caused by coronary artery disease which can cause angina or myocardial infarction

Question 5

Signs?

Answer 5

Pulse/ heart rate is slow. Bradycardia.

Low BP

cardiac syncope - lose consciousness

Question 6

Test results?

Answer 6

ECG completely random.

Question 7

How to treat?

Answer 7

Atropine - blocks vagus nerve and acetylcholine which allows heart rate to increase.

Permanent pacemaker may be needed.