Ventricular fibrillation

Question 1

What is ventricular fibrillation?

Answer 1

an irregular broad-complex tachycardia that can cause cardiac arrest + sudden cardiac death.

Question 2

Explain the aetiology of ventricular fibrillation

Answer 2

Ventricular fibres contract randomly causing complete failure of ventricular function
Most cases occur in pts with underlying heart disease

Question 3

List 5 risk factors for ventricular fibrillation

Answer 3

Coronary artery disease  
AF  
Hypoxia 
Ischaemia  
Pre-excitation syndrome

Question 4

Summarise the epidemiology of ventricular fibrillation

Answer 4

MOST COMMON arrhythmia identified in cardiac arrest patients
Incidence of VF parallels incidence of IHD

Question 5

What are 3 symptoms of ventricular fibrillation?

Answer 5

Chest pain
Fatigue
Palpitations

Question 6

What 6 conditions may pre-exist in ventricular fibrillation?

Answer 6

Coronary artery disease  
Cardiomyopathy  
Valvular heart disease  
Long QT syndrome  
Wolff-Parkinson-White syndrome 
Brugada syndrome

Question 7

What 6 investigations should be carried out for ventricular fibrillation

Answer 7

ECG
Cardiac enzymes (e.g. troponins): for recent ischaemic event
Electrolytes: imbalance
Drug levels + tox screen: anti-arrhythmics + recreational drugs (e.g. cocaine)
TFTs: hyperthyroidism
Coronary angiography: if patient survives VF, to check the integrity of coronary arteries

Question 8

Describe the management plan for ventricular fibrillation

Answer 8

Urgent defibrillation + cardioversion
Pts who survive need full assessment of LV function, myocardial perfusion + electrophysiological stability
Most will need an implantable cardioverter defibrillator (ICD)
Empirical B-blockers
Some may be treated with radiofrequency ablation (RFA)

Question 9

List 6 possible complications of ventricular fibrillation

Answer 9

Ischaemic brain injury due to loss of cardiac output  
Myocardial injury  
Post-defibrillation arrhythmias  
Aspiration pneumonia 
Skin burns (defib)
Death

Question 10

Summarise the prognosis for patients with ventricular fibrillation

Answer 10

Depends on time between onset of VF + medical intervention
Early defib is essential (within 4-6 mins)
Anoxic encephalopathy is a major outcome of VF