Ischaemic Heart Disease Flashcards
What is meant by “ischaemic heart disease”?
a lack of blood supply to the heart muscle, which results in chest pain
What different conditions are classed as ischaemic heart disease?
What do they all have in common?
IHD encompasses stable angina and acute coronary syndrome (ACS)
- ACS is subdivided into unstable angina, STEMI + NSTEMI
they all involve occlusion of the coronary arteries, but to different extents
in stable angina, the arteries are occluded to a lesser extent
How can the different ACS conditions be differentiated from each other?
Troponin blood test:
a negative troponin indicates unstable angina
ECG:
an ECG is performed to look for ST elevation
Why does stable angina (angina pectoris) occur?
Under what conditions does it occur?
it occurs when narrowed coronary arteries prevent blood from reaching the myocardium
it occurs PREDICTABLY and with EXERTION (opposite of unstable)
What are the risk factors for stable angina?
- old age
- smoking
- hypertension
- hyperlipidaemia (high LDLs)
- diabetes
these are the same risk factors for all ACS too
What are the symptoms of stable angina?
chest pain that is provoked by exercise / emotions
the chest pain DOES NOT occur at rest
What investigations are performed for stable angina?
Resting ECG:
to rule out ACS and any other ECG changes
Lipid profile / HbA1c:
to look for diabetes - another RF
What ECG change can sometimes be seen in stable angina?
pathological Q wave
- this indicates a prior infarct (e.g. prev MI)
- it is not necessarily indicative of stable angina
What is involved in the management of stable angina?
First line:
* antiplatelet (aspirin 75mg / clopidogrel) + statin
Additional:
* sublingual GTN spray
* beta-blocker / CCB
How should a patient be instructed on the use of GTN spray?
- use immediately before any planned exercise / exertion
- SEs include flushing, headache + lightheadedness
- sit down or hold on to something if feeling light-headed
- repeat the dose after 5 mins if pain persists
- if pain has not gone 5 mins after second dose, call an ambulance
What drugs may be given to someone with stable angina and why?
aspirin 75mg:
this is first line taking into account risk of bleeding / comorbidities
ACEi:
for people with stable angina + diabetes
statin
How does unstable angina differ to stable angina?
this involves chest pain that occurs unpredictably and at rest
What investigations are performed for unstable angina?
ECG:
to rule out NSTEMI - should have no changes
Troponin:
this should be negative
CXR:
to rule out other causes of chest pain (e.g. aortic dissection)
FBC:
to assess for thrombocytopenia / bleeding risk prior to treatment
following ix - GRACE score should be calculated
What is the first line management for unstable angina?
300mg loading dose of aspirin immediately with an antithrombin (Fondaparinux)
following management depends on the GRACE score
the aspirin is continued indefinitely following the loading dose
What parameters are used for the GRACE score?
When is someone deemed to be high risk?
- age
- history of MI / CHF
- resting HR
- systolic BP
- initial serum creatinine
- elevated cardiac enzymes
6-month estimated mortality of >3% is deemed high risk
What is the treatment for unstable angina if someone is deemed low risk from the GRACE score?
treatment with ticagrelor + aspirin
if they have a bleeding risk (e.g. low platelets) then aspirin + clopidogrel
low risk = 6-month mortality < 3%
What is the treatment for unstable angina if someone is deemed intermediate / high risk from the GRACE score?
- angiography is performed to look at the coronary arteries
- a PCI may be performed if there is NO bleeding risk
- ticagrelor + aspirin is given
- if they are having a PCI, prasugrel is given instead of ticagrelor + aspirin
What is an NSTEMI?
What investigations are performed?
non-ST-elevation myocardial infarction
- ECG
- troponin - this will be POSITIVE
- CXR
- FBC
- calculate GRACE score
there is partial occlusion of a coronary artery
What ECG changes are associated with NSTEMI?
- T wave inversion
- ST depression
What is the first line management for NSTEMI?
- 300mg loading dose of aspirin (continued indefinitely)
- antithrombin (Fondaparinux)
What is the management for NSTEMI depending on the GRACE score?
Low risk (< 3%):
* ticagrelor + aspirin
* if there is a bleeding risk, clopidogrel + aspirin
High risk (> 3%):
* angiography +/- follow-up PCI if indicated
* ticagrelor + aspirin
* if PCI is performed, prasugrel is given instead
PCI may be contraindicated if there is comorbidity / active bleeding
What are the signs / symptoms of an NSTEMI?
- chest pain that radiates to the jaw, arms + shoulder
in males:
* sweating
* SOB
* nausea
in females:
* sweating
* SOB
* upper back pain
What is a STEMI?
What investigations are performed?
ST-elevation myocardial infarction
Investigations:
* ECG
* troponin - will be positive
* coronary angiography if < 12 hours after presentation / gained specialist advice
the coronary artery is TOTALLY occluded
What are the signs / symptoms of a STEMI?
- severe central crushing chest pain +/-
- sweating
- SOB
- pallor
it can be SILENT in the elderly / diabetics
What ECG changes are associated with STEMI over time?
Initially:
* there are hyperacute T waves (very pointy) followed by ST depression
- this is followed by ST elevation
- ST elevation is dependent on the artery affected
- there may be new onset LBBB
How can bundle branch block be recognised?
In which leads are the changes seen?
LBBB - WiLLiam:
* in V1, there is a W shape
* in V6, there is a M shape
RBBB - MaRRow
* in V1, there is an M shape
* in V6, there is a W shape
LBBB can be seen in a STEMI
What is the initial first line management for STEMI?
300mg aspirin + continue indefinitely
What is the management for STEMI if someone has been having symptoms < 12 hours + PCI is possible within 2 hours?
angiography + PCI
- if patient is NOT taking anticoagulants, prasugrel is given
- if patient is taking anticoagulants, clopidogrel is given
they are also given UFH + antithrombins + drug-eluting stent
angiography allows for visualisation of the position of the clot
If someone has had symptoms < 12 hours but PCI is not possible in 2 hours, what is the management for STEMI?
fibrinolysis with alteplast + antithrombin
- they are also given ticagrelor + aspirin
- or clopidogrel + aspirin if bleeding risk is high
ECG is performed 60-90 mins after fibrinolysis
if ST elevation persists, angiography +/- PCI is performed
What is the management for STEMI if someone has had symptoms > 12 hours?
- ticagrelor + aspirin if bleeding risk is low
- clopidogrel + aspirin if bleeding risk is high
medical mx only if symptoms > 12 hrs (no PCI)
