Ventricular fibrillation

Question 1

Define ventricular fibrillation

Answer 1

A cardiac rhythm disturbance that causes cardiac arrest, seen as an irregular broad complex tachycardia on ECG

Question 2

Aetiology of ventricular fibrillation

Answer 2

Chaotic electrical activity, resulting in loss of synchronous contraction -> ventricles cease to pump blood
Most commonly caused by MI

Question 3

Risk factors for ventricular fibrillation

Answer 3

MI
Coronary artery disease
Cardiomyopathy
Electrolyte disturbance
Drug e.g. quinine, procainamide, sotalol, amiodarone etc.
Illicit substances e.g. cocaine, opioids

Question 4

Signs of ventricular fibrillation

Answer 4

Patient unresponsive
Absence of normal breathing or agonal breathing
Absence of circulation i.e. no pulse
Cardiac rhythm disturbance

Question 5

Investigations for ventricular fibrillation

Answer 5

AFTER patient is stable

Continuous cardiac monitoring

FBC
Electrolytes
VBG
Cardiac biomarkers
Echo
ECG 
Coronary angiography

Question 6

Management of ventricular fibrillation

Answer 6

Cardiac arrest management

1. CPR and defibrillator, 30:2 CPR with defib after 5 cycles
2. Adrenaline 1mg IV every 3-5 minutes after the 2nd shock
3. Consider amiodarone or magnesium sulphate after the 3rd defibrillation attempt

Question 7

Complications of ventricular fibrillation

Answer 7

Death
Rib and sternal fractures
Anoxic brain injury
Ischaemic liver injury
Tubular necrosis

Question 8

prognosis for ventricular fibrillation

Answer 8

Most common cause of death following MI
Poor outcome
Rate of arrest decreasing, rate of successful recovery is low
Even if recovered - high risk of complications