Cardiac sudden death Flashcards
What are the 4 H’s of cardiac arrest
- hypoxia
- hypovolaemia
- hypo/hyperkalaemia
- hypothermia
Wischnewski ulcers are found _____ and are associated with___
- gastric
- hypothermia
What are the 4 T’s of cardiac arrest
- thrombosis
- tamponade
- toxins
- tension pneumothorax
When might a cardiac tamponade be seen?
- after MI
- increased fluid
Name 2 complications of MI’s?
- pericarditis
- cardiac aneurysm
Define shock
- condition of inadequate perfusion to sustain normal organ function
Name different types of shock
- cardiogenic
- hypovolaemic
- obstructive
- distrubtive
- cytotoxic
Describe hypovolaemic shock
- loss of circulating volume
- reduced preload and cardiac output
Define preload
- volume in ventricles before systole
Define cardiac output
- amount of blood pumped by the heart per minute
Define cardiogenic shock
- myocardial dysfunction causing reduction in systolic function and cardiac output
Define obstructive shock
- physical obstruction to filling of the heart
Causes of obstructive shock?
- PE
- cardiac tamponade
- tension pneumothorax
Define distributive shock
- significant reduction in SVR
Define cytotoxic shock
- uncoupling of tissue oxygen delivery and mitochondrial oxygen uptake
What moves the frank starling curve up?
- inotropes
What moves the frank starling curve down
- decreased contractility
- failing heart
Rising lactate levels are due to what and what is it a sign of?
- due to hypoperfusion
- septic shock
Neurogenic shock often follows_____
- spinal cord or central trauma
Name 2 shockable cardiac arrest rhythms?
- ventricular fibrillation
- pulseless ventricular tachycardia
Name 2 non-shockable cardiac arrest rhythms?
- pulseless electrical activity
- asystole
What is the CPR ratio advised?
- 30:2
What does transthoracic impedance mean?
- body’s resistance to current flow
How might ventricular fibrillation look on ECG?
- bizarre irregular waveform
- no recognisable QRS complexes
Pulsless ventricular tachycardia has 2 subtypes?
- monomorphic
- polymorphic = torsade de pointes
After 3 shocks and no improvement what should be given?
- adrenaline 1mg IV
- Amiodarone 300mg IV
How should aystole be treated?
- adrenaline 1mg every 3-5mins
Treatment of hyperkalaemia?
- calcium chloride
- insulin/dextrose solution
Treatment of hypokalaemia
- electrolyte infusion
Treatment of cardiac tamponade
- needle pericardiocentesis
How long should CPR be continued after fibrinolytic treatment in a thrombosis?
- 60-90mins
How can the heart increase its cardiac output?
- increase heart rate (tachycardia)
- increase stroke volume (isotropy)
What is the cranial nerve involved in the baroreceptor reflex in the carotid sinus?
- CN IX
- glossopharyngeal
What is the cranial nerve involved in the baroreceptor reflex in the aortic arch?
- CN X
- vagus
What are the 2 categories of cardiac arrhythmias
- cardiomyopathies
- channelopathies
Explain what is meant by a cardiomyopathy?
- related to scar/electrical barrier formation
Explain what is meant by a channelopathie?
- ion current imbalances
Name some cardiomyopathies?
- hypertrophic cardiomyopathy
- dilated cardiomyopathy
- arrthymogenic right ventricular cardiomyopathy
Name some channelopathies?
- long QT syndrome
- brugada
3 divisions of arrhythmia generation?
- automaticity
- trigger
- re-entry
Early afterdepolarisations occur in what phase of the cardiac cycle?
- phase 2 or 3
What is at risk of developing in an early afterdepolarisation?
- torsardes de pointes
Delayed afterdepolarisations occur in what phase of the cardiac cycle?
- phase 4
What can potentiate a early afterdepolarisation?
- hypokalaemia
- amiodarone
Amiodarone does what to the QT interval?
- increased QT interval
Commonest mutation in long QT syndrome effects what channel?
- potassium channel
Diagnosis of long QT syndrome?
- QT >480ms
- mutation
Management of long QT syndrome?
- beta blockers
- avoid triggers
KCNQ1 mutation is associated with?
- Long QT syndrome
Short QT syndrome is mutations to the ____ channel
- potassium
Brugada syndrome has a high risk of ______
- polymorphic VT, VF
What may trigger polymorphic VT in Brugada syndrome?
- rest
- sleep
- excessive alcohol
Treatment of Brugada syndrome?
- ICD
Catecholaminergic polymorphic ventricular tachycardia is autosomal___
- dominant
Explain ECG appearance of Wolff-parkinson white syndrome
- delta wave
- short PR interval
Name the accessory pathway in Wolff-parkinson white syndrome?
- bundle of Kent
hypertrophic cardiomyopathy is associated with mutations in what genes?
= sarcomere
HCM 5-year risk score of greater than ____% indicates the need for a ICD in hypertrophic cardiomyopathy?
- > 4%
Genetic mutations account for ___% of dilated cardiomyopathies, other causes include___
- 20%
- viral, alcohol, diet
