Sudden Death Flashcards
Define sudden death
Death within 24 hours from the onset of symptoms
State the four H’s of cardiac arrest
Hypoxia
Hypovolaemia
Hypo/hyperkalaemia
Hypothermia
State the four T’s of cardiac arrest
Thrombosis
Tamponade
Toxins
Tension pneumothorax
What are non-suspicious causes of hypoxia?
Asthma, pneumothorax, obstruction, respiratory depression, aspiration
What would be classed as a suspicious cause of hypoxia?
Obstruction, overdose, negligence, poisoning, drowning
State the main causes of hypovolaemia
GI haemorrhage, haemoperitoneum, trauma
How can aortic valve disease cause sudden death?
Congenital bicuspid valve is more prone to calcification/endocarditis and may lead to increased heart size due to increased load
What is a typical sign of cholesterol deposition in the eye?
Corneal arcus
How do baroreceptors compensate for hypovolaemia?
Stretch receptors in carotid/aortic arch sense reduced stretch and enhance sympathetic output with inhibition of parasympathetic
What is the sympathetic neurohormonal response?
Release of vasoconstrictors redirects fluid from peripheral/secondary organs
What is the effect of capillary absorption of interstitial fluid?
Reduced hydrostatic pressure
How does the HPA respond to hypovolaemia?
Intrarenal baroreceptors lead to renin release from JGA resulting in Ang II vasoconstriction and ADH secretion
Describe the presentation of cardiogenic shock
Hypotension, fatigue, syncope, raised JVP, oedema, hepatic congestion
Define positive inotropy
Increase force of contraction for any preload
What can cause cardiogenic shock?
Acute MI Acute valve dysfunction Myocarditis Cardiomyopathy Contusion
Name three causes of obstructive shock
PE
Cardiac tamponade
Tension pneumothorax
What is McConnells sign?
Hyperkinetic RV apex
Name the types of shock that come under distributive
Septic
Anaphylactic
Neurogenic
Name two shockable rhythms
VF
Pulseless VT
Name two non-shockable rhythms
Pulseless electrical activity
Asystole
What does VF look like on an ECG?
Bizarre irregular waveform, no QRS, uncoordinated electrical activity
What does pulseless VT look like on ECG?
Monomorphic - broad complex, rapid, constant QRS
Polymorphic - torsade de pointes
Describe drug treatment during arrest
Adrenaline given after 3 shocks Img IV
Amiodarone 300mg IV
What does asystole look like on ECG?
Absent QRS may be atrial activity
What is PEA?
Organised electrical activity in the absence of a pulse
What does each letter of the ECG pattern indicate?
P - atrial depolarisation
QRS - ventricular depolarisation
T - ventricular depolarisation
How do you calculate heart rate on ECG?
regular - 300/number of large squares between beats
irregular - number of QRS in 30 and multiply by 10
Describe the stages of ECG analysis
- Verify patient details
- Check date and time
- Check calibration
- Determine axis
- Rate and rhythm
- Individual leads
Which views of the heart correspond to which artery?
Lateral - circumflex
Inferior - RCA
Septal - LAD
Anterior - RCA
What is first degree heart block?
SA node depolarisation conducted to ventricles but there is a delay - PR prolonged
What is the problem in second degree heart block?
Excitation intermittently fails to pass through the AV node/bundle of His
Describe Mobitz type 1
Gradually PR increases until failure of conduction and beat is missed
Describe Mobitz type 2
Constant PR but occasionally no ventricular contraction
What is third degree heart block?
No APs from SA to AV node
What is a useful way to remember ECG patterns in bundle branch block?
William Marrow
Describe bundle block ECG
RBBB - big R wave in V1 and deep S wave in V6
LBBB - M shape V6, V1 deep S wave
What is normal heart deviation on ECG?
I and aVF are positive
What does atrial flutter look like on ECG?
Saw tooth
What does AF look like on ECG?
Irregularly irregular - p wave abnormality
State the components of the triple risk model
- Critical development period
- Vulnerable infant
- Exogenous stress
Name some of the risk factors for SUDI
Acute illness Premature Congenital anomaly Small for gestation Multiple births Male Depression in carer Alcohol/substance misuse Maternal smoking Poor housing Co-sleeping/soft surface
What is a genetic variant?
Change to DNA sequence
What is a polymorphism?
Variant that is prevalent in the population
What gene is mutated in Marfans?
Fibrillin
Describe Loeys Dietz Syndrome
TBR1 or TBR2 mutations
What is a diagnostic feature of familial hypercholesterolaemia?
Tendon xanthoma
Name some genes associated with FH
LDLR
APOB
PCSK9
