Flashcards in Chronic Chest Pain Deck (21)
Chronic Angina is?
Symptom caused by fixed coronary stenosis in the arteries from atherosclerosis of coronary arteries.
Patients symptoms at rest vs patients symptoms during physical activity
Rest: Blood supply to heart sufficient, patient is symptom free.
Physical activity: as Cardiac work and demand increases, partially occluded coronary vessel prevents this demand from being meet > ischaemic cardiac muscle and chest pain.
Back to rest: rebalance of flow, blood goes away
Is treating chronic angina a medical emergency
No, it is more of a long-standing issue that can be treated. The issue is getting the patient to take their treatment
Classical signs of angina
previous heart issues
Pain/tightness/heaviness during movement, eases at rest.
Does the pain go to neck/L arm?
Investigations you can do to diagnose
-Exercise-test with ECG to show ischaemia as HR inc
-CT scan of coronary arteries
Examination you can do to diagnose angina
Pharmacological: reduce symptoms and/or CVS risk
Interventional: surgery, stent
Pharmacological Treatments that reduce symptoms
-Beta-blockers (decrease energy and cardiac work)
-Calcium channel blockers (VD)
Pharmacological Treatments that reduce CVS risk
-Lipid Lowering (statins)
More about long term outcome
Typical drug list for a patient with chronic angina
1) Beta-blocker; metoprolol
2) Calcium channel blocker
3) isosorbide mononitrate
4) GTN spray 'as required'
This is an issue, as patient compliance is low due to a quite hefty list of drugs they are required to take daily.
-Titrate dose (start w low dose)
-Review patient; symptoms resolution, side effects
Long term followup required
-Reduce cardiac work: decrease HR and c.work (aim HR: 60-70bpm)
decrease ischaemic burden
-FIRST LINE THERAPY to reduce angina symptoms
Calcium Channel Blockers
-Block voltage-operated L-type Ca channels; in cardiac and SM
Vascular smooth muscle: decreases arterial SM tone, vascular peripheral resistance, BP
Cardiac cells: decrease contractility, sinus node rate and AV node transmission
-Some selectivity between tissues
Calcium channel blockers for resistance vessels
- ) flushing, headache, oedema
Calcium channel blockers for cardiac tissue
- )Heart block, negative inotrope, constipation
-Vasodilators, can be used everyday (chronic) or for acute required use (can be done because they are so lipophilic! straight into circulation!)
1) Nitrate-like effect
2) K+ ATP channel opener: hyperpolarises cell and inactivates VC
- Predictable side effects (headaches)
Lipid-lowering drugs: Statins
Primary and secondary prevention
Primary Prevention: treat if 10 year CVS >30%
Secondary Prevention: coronary artery disease (angina)**********, cerebrovascular disease, peripheral vascular disease
Frequently used statins in NZ
Heaps of evidence of effect.
there are some others that are less frequently used due to being less effective
Statins: mechanism of action
Synthasizing cholesterol (in hepatocytes) is v important. Acetyl CoA to cholesterol
Statins inhibit enzyme 'HMG CoA reductase', stoping the step in the pathway
HMG Coa --X---> Mevalonate
Hepatocytes, respond to this by expressing lots of LDL receptors, effectively 'mopping' up the circulating LDL to make/use sufficient cholesterol
LDL levels lower