Arrhythmias

Question 1

What are the 4 possible cardiac arrest rhythms in an unresponsive patient?

Answer 1

Shockable rhythms:
Ventricular tachycardia
Ventricular fibrillation

Non-shockable rhythms:
Pulseless electrical activity - ECG shows heart rhythm that should produce a pulse, but does not
Asystole - no electrical activity

Question 2

How is tachycardia treated in an unstable patient?

Answer 2

Consider up to 3 synchronised shocks

Consider an amiodarone infusion

Question 3

How is tachycardia treated in a stable patient?

Answer 3

Narrow complex (QRS < 0.12s):
AF - rate control with beta blocker or diltiazem
Atrial flutter - control rate with beta blocker
SVT - vagal manoeuvres and adenosine/verapamil

Broad complex (QRS > 0.12s):
VT or unclear - amiodarone infusion
SVT with bundle branch block - treat as normal SVT
If irregular, may be AF variation - seek specialist

Question 4

In which patients should adenosine be avoided?

Answer 4

asthma
COPD
HF
heart block
severe hypotension

Question 5

What is the treatment for bradycardia/AV node blocks?

Answer 5

Stable:
Observe

Unstable or risk of asystole:
Atropine 500ug IV
Repeat dose of atropine if symptoms don’t improve, up to 6 doses for a total of up to 3mg
Can also try noradrenalin or transcutaneous cardiac pacing using a defibrillator