heart med 2 Flashcards
Management
of NSTE-ACS
and ACS (MI)
Aim
of treatment is to stabilise the patient,
treat the lesion and slow progression of
atherosclerosis and prevent future events
The gold standard treatment for STEMI
is revascularization with primary percutaneous
coronary intervention within 2 hrs. Where
this is not available treatment to dissolve the
clot is thrombolysis
Management
of NSTE-ACS
and ACS (MI) drugs
Anticoagulant therapy Thrombolytics agents Antiplatelet therapy Morphine ACE inhibitors
Antiplatelet therapy
Mechanism of action
Example
Adverse effects –
Mechanism of action
Aspirin as per previous slide
• P2Y12 inhibitors –blocks platelet receptors (P2Y12) inhibiting platelet aggregation by blocking
activation of the glycoprotein Iib/IIIa pathway
Example
• Clopidogrel
Adverse effects – severe neutropenia, TTP, haemorrhage
NB: Aspirin (previous slide) and P2Y12 inhibitors given immediately along with GTN (previous
slide) when patient presents with Chest pain
Morphine
• Morphine has been used for analgesic effect and its vasodilator properties in ACS, however it has
been associated with an increased in-hospital risk of death (low grade confidence due to high risk
of bias in these studies). Morphine decreases the antiplatelet effect of P2Y12 inhibitors.
Beta blockers
• Unless contra indicated they should be used to reduce infarct size and ischemia
ACE inhibitors (
Long term management of ACS – improves survival and used for secondary prevention
Anticoagulant therapy
Mechanism of action
Example
Adverse effects
• Combines with antithrombin III inactivating factor X and inhibiting conversion
of prothrombin to thrombin. If thrombin exists, inhibits further coagulation
(Heparin)
• Activates antithrombin inhibiting generation of thrombin, as well as
accelerating inhibition of factor Xa
Example
• Heparin, Enoxaparin (LMWH)
Adverse effects – haemorrhage, elevated liver enzymes (both), anaemia, nausea,
diarrhoea, fever (enoxaparin
Thrombolytics agents
Mechanism of action
Example
Adverse effects
Mechanism of action
• Recombinant tissue plasminogen activator (r-tPA)) which acts on fibrin in
thrombus with little or no effect on circulation unbound plasminogen
(Dissolves existing clots)
• Re-perfuses occluded vessels in approximately 90 minutes in most patients
Example
• Alteplase, reteplase
Adverse effects –haemorrhage at IV site, minor or major bleeding, arrhythmias
(associated with reperfusion), hypotension
Most antiarrhythmic drugs have two
actions that reduce abnormal electrical
activity
1. Suppress abnormal (ectopic) pacemakers more than they do the SA node 2. They increases the ratio for the effective refractory period to action potential durations While they are divided into 4 classes, many of them have properties of more than one class
Management of Arrhythmias/dysrhythmias
Class I
Class II
Class III
Class IV
Class I
Management of Arrhythmias/dysrhythmias
Sodium channel blockers
•Act mainly by blocking sodium channels (depressing impulse conduction).
•Can also suppress automaticity by raising the membrane potential threshold required for delayed afterpolarizations
to trigger action potentials
Side effects – arrhythmias, other side effects depend on subclass and range from N & V, syncope, tinnitus, anxiety,
insomnia, increased sweating
Class II
Beta blockers
• Used for rate control in arrhythmias
• Reduce the conduction of the atrial impulse through the AV node
Side effects – as previously discussed
Class III
Potassium channel blockers
•Prolongs action potential duration and hence refractory period of atrial, nodal and ventricular tissues
•Increases coronary blood flow by vasodilation
•Suppresses ectopic pacemaker
Side effects – Bradycardia, cardiac failure and cardiac arrest. MANY cumulative adverse effects. Pulmonary fibrosis,
hypo and hyperthyroidism, liver dysfunction, photosensitivity , smurf syndrome, and peripheral neuropathy. It has a
very long half life (average 58 days)
Class IV
Calcium channel blockers
•Their blockage slows AV node depolarisation and conduction and also increases its refractory period
Side effects - headaches, dizziness, GI symptoms, palpitations, hypotension, exacerbation of angina, rash