Ventricular Fibrillation

Question 1

def

Answer 1

an arrhythmia which occurs when the heart beats with rapid, erratic electrical impulses
causes the ventricles to quiver uselessly instead of pumping blood

Question 2

aetiology

Answer 2

1 IHD
2 VT
3 MI
4 cardiomyopathy
5 myocarditis

Question 3

epi

Answer 3

a significant cause of sudden death in the UK

survival rates are 2%

Question 4

what can VF cause

Answer 4

cardiac arrest + sudden cardiac death

due to complete failure of CO

Question 5

history

Answer 5

1 sudden loss of consciousness
–earlier–
2 dizziness
3 chest pain

Question 6

what is agonal breathing a sign of

Answer 6

hypoperfusion of brainstem

Question 7

risk factors

Answer 7

1 previous VF
2 previous MI
3 cocaine or methamphetamine
4 electrolyte abnormalities (K, Mg)

Question 8

examination

Answer 8

1 agonal (rasping, laboured) breathing
2 syncope
3 rapid, fluttering heartbeat

Question 9

investigations

Answer 9

diagnosis
1 heart monitoring
-reads the electrical impulses of the heart
2 pulse
-no pulse in VF
diagnose cause of VF
1 ECG
-may show MI
2 bloods
-cardiac enzymes
3 CXR
-visualize heart + heart vessels

Question 10

management

Answer 10

1 precordial thump
2 attach cardiac monitor + defibrillator
3 assess rhythm
-if pulseless VT or VF

defibrillate in shock cycles: 200J, 200J, 360J (all subsequent cycles are 360J)
resume CPR
reassess rhythm
adminster adrenaline (1mg IV) after second defibrillation and again every 3-5mins
if ‘shockable rhythm’ persists after third shock, administer amiodarone 300mg IV bolus

Question 11

complications

Answer 11

1 loss of consciousness
2 cardiogenic shock
3 cardiac arrest
4 death

Question 12

prognosis

Answer 12

with every minute after VF, chance of successful defibrillation declines by 10%
high mortality even in short delay time to fibrillation