Angina Flashcards
Chest pain due to transient myocardial ischaemia
Angina pectoris
Cardiac work
Oxygen needs
Coronary flow
Oxygen supply
Determinants of demand
Heart rate
Systolic
Myocardial wall stress/tension (determined by systolic)
Contractility
Determinants of supply
Coronary artery diameter
Collateral blood flow
Perfusion pressure (subendocardial before subepi)
Heart rate
Angina of effort - on exertion
Atherosclerosis
Decrease cardiac work
Unstable(crescendo or pre infarction) - mild exertion
Occlusion on top of atherosclerosis (the plaques broke)
Hospitalisation VD decrease cardiac work and antithrombotic
Variant - at rest
Reversible coronary VC
Coronary VD treatment
Angina drugs never given on their own - adjuvants
All of them:
Anti angina
-VDs and drugs that decrease cardiac work like nitrates and CCB
-only decrease cardiac work like BB
-others
Adjuvant drugs
The others
Nicorandil - nitroD(release NO) and k channel opener
Trimetazidine
Ranolazine
IvaBRAdine - bradycardia
Adjuvant
Anti platelet - aspirin, clopidogrel, ticlopidine
Treatment of risk and precipitating factors - anti hypertensive, hyperlipidemi, diabetic, anxiety
Isosrbid dinitrate
Has a slower onset and greater duration of action than mononitrate
All organic nitrates jndergo extensive and variable first pass with only 10%bioavailability except for
Isosorbid mononitrate
Anyways SR tabs for the rest
Nitrates are denitrated by
Glutathione transferase (consumes SHmeaning SH dependent?)
Nitrates act by
2 Mechanisms: calcium and MLCK dephosphorylation while B blockers act through 1
Nitrates inhibit
Platelet aggregation
Pharmacology
BV heart hypotension spasmolytic RC
Nitrates act on veins because
They expressed greater amount of enzyme than arteries
Veno d
Nitrates: decreased vr edv and preload
Arterio d
Nitrates: decreased TPR decreasing afterload
Meningeal VD
Headache
Cutaneous VD
Flushing and nitroid reaction
Pulmonary VD
VR and pulmonary presdure
Decreased pressure on subednocardial coronaries
Decreases Contractility
Short acting sl or buccal apray
Acute or prodrome
GTN
Isosorbid
Long acting chronic
GTN - SR transdermal delivery
Iso Di - tablets or SR
Iso mono - tabkwbs⁷
GTN (IV) limits the area of necrosis in MI…
By fabourably altering oxygen balance in the marginally partially ischaemic zone
Congestive heart failure reduction
Because NO (IV) reduce preload and receive pulmonary congestion shifting blood to systemic circulation
Continuous gemodynamic changes
To monitor changes after IV TmGTN infusion for congestive heart failure
Morphine causing biliary colic
Treat with GTN or isisorbide dinitrate
Sodium nitrite
The nitrate you take IV to generate enough methemoglobin in cyanide poisoning without hypotension
Tadalafil and sildenafile
Phosphodiesterase inhibitors so VDs
CCBs
Dihydropyridine
Non - dihydropyridine
Dihydropyridine VD
Dipine family: amlodipine, nifedipine *specific to bv causing VD, nitrendipine, felodipine, isradipine, nicardipine and nomodipine
Long acting- amlodipine
Intermediate- FINN
Short- Nicardopine nimodipine
Non dihydropyridine
Verapamil (arrhythmia) and diltiazem
-specific to heart causing inhibition more than effects on bvs
-ve chronotropy
Inhibit SAN so bradycardia and prolonged diastolic so antagonises tachycardia you get from nitrates
-ve inotropy
Decreased cardiac work and oxygen consumption
-ve dromo
Decreases AV node consumption
So contraindicated in heart block
Not combined with beta blockers or digitalis
Nodihydros (plus class 4 antiarrhythmics) because -ve dromo
Hypotension too from reflex stimulation
Nifedipine (bv moes than heart)
Potent coronary VD but less peripheral VD with less hypotension than nifedipine
Nodihydros
Potent arterio but weak veno D so less after load than preload decrease
Nifedipine
Steal phenomenon (where small coronaries steal from the ischaemia site
Nifedipine
Dihydros don’t inhibit AVN so…
Allowed in heart blocks
Dihydros have minimal -ve intoropy (affects afterload and preload so minimal)
So allowed in heart failure
In Hypertrophic obstructive cardiomyopathy
No dihydros
Alternative fo premature labour
Nifedipine (plus hypertension)
Migraine prophylaxis CCB
Nimodipine(bbb so CNS) and flunarizine
Adverse effect of verapamil
Constipation
Ankle oedema
Adverse effect of nifedipine
Verapamil lobes drugs that aggrevate heartblock(-ve dromotropy like itself)…
Decreased renal excretion of dioxin
With beta blockers causes severe cardiac depression(heart block)
Nifedipine and nitrates no go
Both cause hypotension and then reflex tachycardia
Indapmide
Subdueretic dose of thiazide in treatment of hypertension
Nifedipine and indapamide(minimal effects on electrolyte and metabolites) allowed in renal patients
As undergo biliary excretion
Beta blockers used
*Those without ISA
Non selective - propranolol nadolol
Selective beta 1 - metoprolol atenolol bisoprolol
Vaso Ds - carvedilol
Beta blockers don’t cause Vaso d (they only block heart) but
There’s nothing wrong with subendocarfial flow as there’s favourable redistribution (non selective block beta2 as well so VC) and decrease in ventricular wall tension
Contraindicated in variant angina
Beta blockers
Never abruptly discontinued
Like nitrates
Beta blocker
CCBd and nitrates decrease ischaemia by
Increasing total coronary flow and distribution of flow to ischaemic sites
Increase subendocardial Perfusion by dilating collaterals and decrease intraventricular pressure and resistance
Improve coronary dustribution
Beta blockers through reducing intraventricular pressure
Anything(not hydropyridines) with beta blocker
Preventing tachycardia and increasing diastolic coronary perfusion
Antiplatelets
Aspirin SD inhibit TXA2
ADP receptor blockers - Ticlodipine and Clopidogrel
GP 1b and 3a receptor blockers - abxiximab and tirofiban
Nicoradil orally for angina and HF
Dual mechanism of action
Trimetazidine (orally add on)
pFOX attached acid oxidation pathway inhibitor
Shifts from fatty acids to glucose during ischaemia decreasing lactate and oxygen demand
Ranolazine
Inhibits late Na decreasing Ca
-Decreases Contractility
-Decreases oxygen demand
Ivabradine for chronic stable angina
Taken With beta blockers
Normal sinus rhythm
HR 70 and above
Ivabradine
BradyC through inhibition of pacemakers for normal spontaneous diastolic depolarization
