ischaemic disease Flashcards
what is atherosclerosis?
hardneing of the arteries due to non-plaque factors
what is angina and characteristics
a symptom of CHD
- insufficient oxygen supply to myocardium (ischaemia)
- pain in the chest/ arm/ neck , sweating and breathlessness
4 types of anginas?
stable angina
unstable angina
variant angina
microvascular angina
what is stable angina?
predictable pain - on exertion e.g whilst doing exercise
almost always caused by atheroma (plaque)
what is unstable angina - acute coronary syndrome
pain on less and less exertion or at rest
normally caused by ruptured atheroma - not just plaque
what is variant angina?
rare
often artery spasm
normally associated with atheroma
microvascular angina
not always due to atheroma
pain = severe
may not respond to normal treatments for angina
What is MI and causes
Myocardial infarction
- caused by coronary artery block by rupture of atheroma and thrombus formation
- loss of oxygen area of heart supplied by blocked coronary artery - prolonged loss of oxygen - irreversible cell death -apoptosis or necrosis
What are symptoms of MI
similar to angina attack
pain in the chest/ arm/ neck , sweating and breathlessness
what are the 3 steps of diagnosis for MI (WHO)
- patient history of chest pain, angina and unstable angina \
- ECG changes
- cardiac biomarkers - troponin
What is STEMI?
ST segment is elevated
what is NSTEMI?
ST segment normal (of ECG)
name an organic nitrate and use
glyceryl trinitrate (GTN)
cause relaxation of smooth muscle by liberation of nitric oxide and generation of cGMP.
- dilate coronary artery - re-distrubute blood to ischaemic regions
-reduce cardiac oxygen consumption
-prevent/relieve coronary spasm
what are the problems caused by organic nitrates
- prone to develop tolerance - avoid by having nitrate overnight
- action is short - passes first pass metabolism as it is a spray or sublingual tablets and rapidly absorbed into the blood stream
- side effects: flushing , headache, postural hypertension
what are examples of calcium channel blockers
Diltiazem and verapamil
what is the use of calcium channel blockers
vasodilators reduce heart rate reduce force of contraction dilate arteries reduce oxygen demand of heart, dilate coronary arteries
what are examples of b1 receptors
atenolol and bisoprolol
carvedilol
what is the function of b1 adrenoreceptor antagonist
reduce oxygen demand of the heart by inhibiting sympathetic drive to heart
what is angioplasty: percutaneous coronary intervention (PCI)
- catheter inserted in femoral or radical arteries
- stents placed in narrowed coronary artery
- stent is expanded increasing arterial diameter and blood flow
what is angioplasty: coronary bypass
taking a healthy blood vessel form the hands or legs and connecting it below and above the arteries in the heart to redirect the blood from the blocked artery.
management of first presentation of chest pain - ACS
- check last episode of cheat pain - to rule out any non -cardiac pain
- assess symptoms
chest pain longer than 15 min
pain associated with nausea, vomiting, sweating, breathlessness
new onset deterioration of stable angina
-refer as emergency is ACS is suspected or currently has chest pain or 12 lead abnormal ECG
refer for same day assessment: pain last 12 hours but pain free now, last episode was 12-72 hours ago
what is the management of stable angina
Primary and secondary
organic nitrate - management of pain episodes
b blocker - prophylaxis of angina pain
calcium channel blockers + BB used in resistant angina
secondary prevention
- low dose aspirin
- statin
- ace inhibitor
- treatment for hyper tension
- does patient need pci/angioplasty
what is the treatment of ACS (unstable angina and NSTEMI)
aspirin 300mg until clinical decision is made
angiogram - high risk patients
PCI angioplasty if required
low risk dual antiplatelets ticagrelor with aspirin
secondary:
- drug therapy - 12 month dual antiplatlets
- acei or arb
- beta blocker 12 months - bisoprolol (if contradicted verapamil or diltiazam)
- statin
treatment for STEMI
- pre-treatment - 300mg aspirin (until clinical decision is made)
- reperfusion therapy - PCI
- dual antiplatelets therapy for 12 months( prasugrel (check bleeding risk ) with aspirin)
- If PCI not an option - fribrinolytic drugs - steptokinase and alteplase
secondary:
- drug therapy - 12 month dual antiplatlets
- acei or arb
- beta blocker 12 months - bisoprolol (if contradicted verapamil or diltiazam)
- statin
examples Fribinolytic
Streptokinase and altepase
