Ventricular fibrillation

Question 1

define:

Answer 1

irregular broad complex tachycardia that can cause cardiac arrest and sudden cardiac death - MEDICAL EMERGENCY

Question 2

Aetiology:

Answer 2

ventricular fibres contract randomly and not together leading to improper ventricular function

can be caused by fibrosis post MI as these parts of the heart do not pass electricity

Question 3

Risk factors:

Answer 3

CORONARY ARTERY DISEASE (most common cause)

hypoxia

AF

drugs

electrolyte imbalance

pre-excitation syndrome

ischaemia

Question 4

Epidemiology:

Answer 4

most common arrhythmia in cardiac arrest

incidence of VF is similar to that fo IHD

Question 5

Signs/symptoms:

Answer 5

may have a history of :

• chest pain
• palpitations
• fatigue

pre-exisiting condition:

• coronary artery disease
• IHD
• WPW syndrome
• Brugada syndrome
• valvular disease
• long QT syndrome

Question 6

investigations:

Answer 6

ECG - this will be chaotic and there will be no identifiable P/QRS/T waves.

Cardiac enzymes (troponins to look for ischaemia)

Coronary angiography post episode

TFTs

Drug levels - anti-arrhythmias and cocaine can lead to arrhythmia

Question 7

Management:

Answer 7

Defibrillate within 4-6 mins + cardioversion

Full assessment of electrophysiological stability

all patients are fitted with a ICD (implantable cardiverter defibrillator)

empirical beta blockers

may have radio-frequency ablation

Question 8

complications:

Answer 8

ischaemic brain injury

myocardial injury

death

aspiration pneumonia

skin burns

death

post-defib arrhythmia

Question 9

prognosis:

Answer 9

fatal if defib not in 4-6 mins

prognosis depends on how quickly there is medical intervention

anoxic encephalopathy is common in VF