Stable Angina and Anti-Angina Drug Pharmacology Flashcards
What is angina and what is it caused by?
Chest pain due to reduced coronary artery blood flow
Describe the feeling and location of angina pain.
Tight-band/crushing pain
Retrosternal
Radiates to jaw or left arm
Lying down eases angina pain - true or false?
False - makes it worse, eases upon sitting forward
When does angina normally happen?
When myocardial O2 demand increases - exertion, cold weather, large meal etc
What three things regarding coronary arteries can cause angina? - place in order of how common.
Coronary atheroma
Coronary artery spasms
Coronary inflammation
What else causes angina which is uncommon?
Reduced O2 transport - anemia
Increased O2 demand - LVH or thyrotoxicosis
What are the non-modifiable risk factors for angina?
Gender - Males and post-menopausal females
Age
Genetics/Family history
What are the modifiable risk factors?
Hypertension
Hyperlipidaemia
Hyperglycaemia
Smoking
What symptoms do you look for in a history of a patient with suspected angina?
Dyspnoea and fatigue on exertion
Syncope on exertion
Chest pain -restrosternal radiating to left arm/jaw
What signs might be present?
Tar stains - smoker Obesity xanthalasma and corneal arcus Hypertension Bruits Abdmonial aortic aneurysm Absent or reduced peripheral pulses Retinopathy
What’s retinopathy?
Damage to retina
Name the investigations?
Blood checks CxR ECG ETT Myocardial perfusion imaging Invasive angiography
What to look for in bloods?
FBC
Lipid profile
Fasting glucose
Us and Es
What to look for in a CxR?
Can exclude other causes of chest pain such as pulmonary oedema
What to look for in ECG?
Pathological Q-waves
LVH - ST depression
What makes an ETT positive?
Angina symptoms with St-segment depression on exertion relatively quickly
Does a negative ETT mean that angina is excluded?
No - but if there was a high workload prognosis is good
Myocardial perfusion imagine - better or worse at detecting CAD?
Better as it shows localisation of ischemia and size of area affected
What are some negatives of myocardial perfusion imaging?
Expensive
Uses radiation
How is myocardial perfusion imaging carried out?
Stress applied to patient via exercise or pharamlogically
Tracer injected via IV twice - at rest and at peak stress
Two reading compared
When does myocardial perfusion imaging show ishchaemia?
If tracer seen at rest but not at peak stress
When does myocardial perfusion imaging show infarction?
If tracer is not seen at all in both readings
When would invasive angiography be used?
If there is a strongly positive ETT suggesting multivessel disease
If angina won’t clear with meds
If diagnosis still not clear
If patients are young
If there is a high occupational risk with patients - like a driver having an angina attack and crashing
How is invasive angiography carried out?
Cannula inserted into radial or femoral arteries, passed to aortic root and into ostium of coronary arteries
Contrast is injected and an image of vessel lumen is viewed on an x-ray
Severity: Stage 1?
Symptoms only on significant exertion - none on rest
Severity: Stage 2?
Slight limitation of daily activities - symptoms on walking more than 1 flight of stairs
Severity: Stage 3?
Marked limitation of daily activities - symptoms on only one flight of stairs
Severity: Stage 4?
Symptoms on the most basic activities such as washing or getting dressed
What are the steps in a medical treatment regime?
1 - Prescribe a short acting nitrate - GTN spray
2 - Beta blockers or CCBs
3 - Swap between beta blockers and CCBs or use both together
4 - revascularisation
How do nitrates work?
Vasodilators - relax smooth muscle by releasing cAMP
Venodilatiors - reduces venous return
This reduces preload and afterload which reduces myocardial O2 demand
Do nitrates relieve coronary vasospasm?
Yes
Adverse drug reactions of nitrates ?
Headache
Hypotension - GTN syncopes
What is step 2 in a treatment regime?
Prescribe either B.blockers or CCBs
Name some beta blockers?
Bisoprolol
Atenolol
How do beta blockers work?
They are rate limiting drugs
Block B1 and B2 receptors which blocks noradrenaline or adrenaline binding to it.
There for it blocks the sympathetic response
What do beta blockers reduce?
HR Force of contraction Velocity of contraction CO BP
What do beta blockers protect myocytes from?
O2 free radicals during ischaemic period
Beta blockers increase exercise threshold - T or F
True
Contraindictions of beta blockers?
Asthma - (Blocks B2 agonist response)
Peripheral vascular disease
Heart failure - these patients depend on sympathetic drive
Bradycardic patients - causes heart block
Adverse drug reactions of beta blockers?
Tiredness
Bradycardia
Rebound - if taken off suddenly can induce a MI
Drug - Drug interactions of beta blockers?
Anti-hypertensive agents - hypotension
Rate limiting drugs - bradycardia/heart failure
NSAIDS - blocks anti-hypertensive actions
Insulin - masks effects
How do CCBs work?
Block L-type channels
What are the 2 types of CCBs - name some drugs for each
Rate limiting - verapamil and diltiazem
Vasodilating - amlodipine felodipine
What is the purpose of using CCBs?
Both types work to reduce myocardial O2 demand (rate limiting) and workload (vasodilating)
Contraindictions of CCBs?
Don’t use nifedipine as its a rapid vasodilator and can cause a stroke/MI
Post MI patients as can increase morality/morbitiy
Unstable angina
Adverse drug reactions for CCBs?
Ankle oedema which doesn’t respond to diuretics
Headache
Flushing
Palpitations
Adverse drug reactions of just rate limiting CCBs?
Bradycardia
Constipation
What is step 3 in treating angina?
Swap between B.Blocker or CCB
or
Use both together
What is step 4?
Consider revascularisation
In patients with atherosclerotic plaques - what other drugs should we give as a routine?
Aspirin/Clopidogrel
Statins
How does aspirin work?
Anti-platelet aggravater
Inhibits platelet thromboxane production which makes platelets
Whats a bad side effect of aspirin?
Causes bleeds - especially GI - be wary when giving to elderly
How does clopidogrel work?
Also stops platelet aggregation
Inhibits ADP platelet activation
Side effects of clopidogrel?
Also causes bleeds - not as much in GI though
How do statins work?
HMG Co-A reductase inhibitors
Reduce cholesterol
If a patient cannot take b.blockers or CCBs - what is some alternative treatment?
Long acting nitrates
Ivabradine
Nicorandil
Ranolazine
Desribe long acting nitrates
Isosorbide mono/di nitrate
Sustained release via tablets
Whats a problem with long acting nitrates and how is it overcome?
Tolerance quickly develops
Give doses at 8am and 2pm for a sustained release period followed by a nitrate free period
How does ivabradine work?
Sinus node inhibitor
Rate limiting
Slows the diastolic depolarization of sinus node
How does nicorandil work?
K+ channel opener
Also known as a preconditioner
The influx of k+ stops the influx of Ca2+ into cells giving a negative inotropic response, vasodilation and venodilation
What does inotropic mean?
Force of contraction
Surgical treatment - how does PCI work?
Same as invasive angiography - but a balloon and stent are placed in the vessel to “widen” it and squash the plaque
What drugs must be given if a stent is placed in the artery?
Aspirin and clopidogrel to stop platelet activation until the body no longer regards the stent as a foreign opject
This stops thrombosis
Does stenting cure the disease?
No - it only really deals with symptoms
Risks of PCI and stenting?
Re-stenosis
Emergency CABG
MI
Death
When is a CABG used?
When there is a mutlivessel disease or the anatomy is unsuitable for PCI
Does CABG have a longer lasting benefit?
Yes - but graft can begin to deteriorate after 10 years
What subgroups benefit more from a CABG?
If there is a 70% stenosis of the left main stem artery
If there is a 3 vessel CAD
A 2 vessel CAD with either significant stenosis of left main stem artery or less than 50% ejection fraction
Describe the CABG procedure.
Long saphenous vein (commonly used) or mammary artery taken
If a vein needs to be reversed so valves face the right way
Attached to aorta distal to site of blockage to BYPASS it
IS CABG safer than PCI?
Yes - fewer risks BUT these risks are higher
What are the risks of CABG?
Death
Q-wave MI
