Week 3 Flashcards
Why is blood flow in capillaries slow?
Allow adequate time for exchange
What can pass through the pores of the capillary wall?
Small water soluble substances
Na, K, glucose, amino acids
What can pass through the endothelial cells of the capillary wall?
Lipid soluble substances
O2, CO2
How are exchangeable proteins transported across the capillary wall?
Vesicular transport
What law of diffusion does movement of gas and solutes follow?
Fick’s Law
What is net filtration pressure?
Forces favouring filtration - forces opposing filtration
What is Kf?
Filtration coefficient
What forces favour filtration?
Capillary hydrostatic pressure
Interstitial fluid osmotic pressure
What forces oppose filtration?
Capillary osmotic pressure
Interstitial fluid hydrostatic pressure
What does a positive net filtration pressure favour?
Filtration
What does a negative filtration pressure favour?
Reabsorption
Would filtration or reabsorption be favoured at the arteriolar end?
Filtration
Would filtration or reabsorption be favoured at the venular end?
Reabsorption
What happens to fluid that accumulates in the interstitium?
Lymphatic system helps to drain
Is resistance higher or lower in the pulmonary circulation than systemic?
Lower
What is oedema?
Accumulation of fluid in interstitial space
Does lung compliance increase or decrease in pulmonary oedema?
Decrease
In HF is the RAAS upregulated or downregulated and what does this result in?
Upregulated
More fluid retention
What signs may be seen in R ventricular failure?
Peripheral oedema
Why is angina affected by the cold?
Cold causes vasoconstriction and increases afterload of the heart
What are the acute coronary syndromes?
Unstable angina
NSTEMI
STEMI
What immediate deadly arrhythmia may occur in a STEMI?
Ventricular fibrillation
What HF can be caused after STEMI?
L due to scar tissue affecting pumping
What features may be seen on a STEMI ecg?
ST elevation
T wave inversion
What ecg changes are needed to diagnose a STEMI?
> 1mm ST elevation in 2 adjacent limb leads
or
2mm elevation in at least 2 continuous precordial leads
or
New onset bundle branch block with associated symptoms
Give examples of thrombolysis medications?
Streptokinase
tpa
What are the absolute contraindications to thrombolytic therapy?
Previous haemorrhagic stroke
Stroke within 6 months
CNS damage or neoplasm
Active internal bleeding
Aortic dissection
Recent major surgery or trauma
Known bleeding disorder
What is the early treatment for STEMI patients?
Aspirin 300mg
Clopidogrel 600mg
Morphine
Anti-emetic
GTN if BP <90
Angioplasty or thrombolysis
What is the travel time for PCI over thrombolysis?
90 minutes
What structural complications can result from MI?
Cardiac rupture
Ventricular septal defect
Mitral valve regurgitation
Left ventricular aneurysm
Mural thrombus
Acute pericarditis
Dressler’s syndrome
What functional complications can occur after MI?
Acute ventricular failure
Cardiogenic shock
HF
What is the KILLIP classification used in?
In hospital mortality following MI
What may be seen in an NSTEMI ECG?
ST depression
T wave inversion
May be normal
What troponins are specific to the heart?
Troponin I and T
What anti platelet therapy is used after a stent?
Dual anti platelet therapy
What conditions other than MI may raise troponin?
CCF
HTN crisis
Renal failure
PE
Sepsis
CVA
Pericarditis/ myocarditis
What are the 2 types of HF?
Heart failure with reduced ejection fraction
Heart failure with preserved ejection fraction
What is the most useful diagnostic test in HF?
Echocardiography
What type of echo tends to be used in HF?
Transthoracic
What blood test may be used in identifying HF?
BNP
What value would be a normal Nt-proBNP?
<400
What BNP value would suggest standard echo waitlist and what would suggest urgent?
Standard: 400 - 2000
Urgent: >2000
What conditions can lead to HF?
HTN
Diabetes
Coronary heart disease
Tachy arrhythmias
Dilated cardiomyopathy
What is a normal ejection fraction?
> 50%
What is ivabradine?
SGLT2 inhibitor
Does ivabradine work in AF?
No
What impact does ivabradine have on HR?
Slows
What are the 4 pillars of HF treatment?
ARNI
BB
MRA
SGLT2i
What does ectopy mean in relation to arrhythmia?
Single beats
In SVT where does the arrhythmia originate?
Above the ventricle - SAN, Atria, AVN, His
What may be seen in ECG of SVT?
Rapid P wave or ‘f’ waves of AF
Narrow WRS
What are the common types of SVT?
Atrial - AF, atrial flutter, ectopic atrial tachycardia
Bradycardia - Sinus bradycardia, sinus pauses
What occurs in AF?
Atrial depolarisation random and fast losing all meaningful contractions
AV node blocks so ventricles much lower rate
Where does ventricular tachycardia originate from?
Ventricular myocardium (common)
Fascicles of the conduction system (uncommon)
What does the QRS look like in ventricular tachycardia?
Wide QRS
What does the ECG look like in ventricular tachycardia?
QRS rapid, wide and distorted
T waves large with deflections opposite the QRS complexes
Usually regular ventricular rhythm
Usually no visible P waves
PR interval not measurable
What is the cardiothoracic ratio?
Maximum diameter of the heart divided by maximum diameter of the thorax
Normal >50%
What type of x-ray will exaggerate the heart size?
AP
What are the 4H and 4T causes of cardiac arrest?
Hypoxia, hypovolaemia, hypothermia, hypokalaemia/ hyperkalaemia
Tension pneumothorax, tamponade, toxins, thrombus
What depth should chest compressions reach?
At least 5cm no more than 6cm
What rhythms are shockable?
Ventricular fibrillation
Pulseless ventricular tachycardia
Is asystole a shockable rhythm?
No
What drugs are given in line with defibrillation?
Amiodarone after 3 shocks
Adrenaline every 3-5 minutes
How is adrenaline given in non-shockable rhythm?
Immediately and repeated every 3-5 minutes
When should CPR be terminated?
Valid and relevant advanced directive
Obvious mortal injury/ irreversible death
Safety threat to ALS provider
Persistent asystole >20 mins despite ALS without reversible cause identified
