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