ELM 12: Angina Flashcards
What is angina?
Chest pain caused by cardiac ischaemia
Resolves within a few minutes of rest
What is acute coronary syndrome?
Same cause as angina but doesn’t resolve quickly with rest
What is angina pectoris?
Crushing pain in chest from cardiac ischaemia that can radiate to arm or jaw
What types of angina are caused by an atherosclerotic plaque in a coronary vessel?
Stable and Unstable
What two types of angina are caused by vessels constricting and spasming?
Prinzmetals angina
Microvascular angina
What is STABLE angina?
Most common
Plaque is stable
Oxygen demand increases in stress and not enough blood to supply demand
Triggered by stress on heart
Relieved with rest
What is UNSTABLE angina?
Rare and more serious
Plaque with weakened cap that ruptures and blood clot forms on top
Further occlusion of flow which can progress into heart attack
Unpredictable triggers and not fixed with rest
What are two ways of treating angina?
Reducing oxygen demand
Increasing oxygen supply
What is meant by a first pass metabolism?
Drug absorbed in gut and taken to liver and not make it fully through the liver
What are some treatments of stable angina?
Aspirin
Statins
Organic nitrates
Beta blockers
Calcium channel blockers
K channel activators
What are some examples of organic nitrates?
Glyceryl trinitrate
Amylnitrate
Isosorbide dinitrate
Nicorandil
What is nitroglycerine/glyceryl trinitrate?
Given either sublingually buccally or by a patch to avoid first pass metabolism
How do organic nitrates reduce angina attack?
Reduce cardiac work and cardiac oxygen demand and preload and after load
Dilate peripheral blood vessels so blood doesn’t push so hard
Arteriolar dilation to reduce resistance
How do organic nitrates improve coronary blood supply?
Collateral vessels dilate
Can skip the blocked area
What are some unwanted effects of organic nitrates?
Flushing
Headache
Postural hypotension
Reflex tachycardia
What are some long acting organic nitrates?
Isosorbide mononitrate and dinitrate
Effective when swallowed
What is nicorandil?
Other treatment of angina
Activates potassium channels
Dilates arteries and veins
What are some side effects of nicorandil?
Vomiting
Headache
Flushing
Hypotension
Nausea
Vomiting
What are two calcium channel blockers to treat angina?
Verapamil
Amlodipine
What is verapamil?
More potent on heart than vascular smooth muscle
Calcium channel blockade reduces heart rate and CO
Use dependent blockade of calcium channels
What is amlodipine?
More potent on vascular muscle than heart
Dilation of capacitance veins reduce cardiac preload
What is an angioplasty?
Surgical method of treating angina
How does an angioplasty work?
- Catheter put into large vessel and threaded into blocked arter
- Visualised using radio opaque dye and xray
- Balloon inflates and opens artery and pushes in stent
When is an angioplasty used?
To treat angina that can’t be controlled by drugs
Emergency of heart attack
What are some adverse effects of an angioplasty?
Stroke
Heart attack
Cognitive decline
Restenosis
What is CABG?
Coronary artery bypass graft
Open heart surgery to remove non essential blood vessel from another part of body
When is a CABG used?
To treat angina resistant to drugs
Location means a stent isn’t suitable
What are some side effects of CABG?
Poor wound healing
Blood loss
Dysrhythmias
Heart attack
Cognitive decline
Grafts only last 15 years
