ACS Flashcards
What are the differential diagnoses of chest pain?
CV - Myocardial ischaemia
- Aortic stenosis
- Tachyarrhythmias
- Cocaine use
- Anaemia
- Thyrotoxicosis
CV - non-ischaemic
- Aortic dissection
- Pericarditis
Upper GI
- GORD
- Gallstones
- Peptic Ulcers
- Pancreatitis
Resp
- Pulmonary embolism
- Pneumothroax
- Pneumonia
- Pleurisy
Musculoskeletal
- Costochondritis
- Herpes zoster / Shingles
What is ACS?
Acute myocardial ischaemia/infarction due to partial or complete occlusion of a coronary artery.
It is divided into 3 clinical categories depending on
- Presence of ST-segment elevation
- Troponin or creatine kinase
What is an NSTEMI?
Partial occlusion of a vessel with likely no dead tissue and limited to the subendocardium
What is a STEMI?
Complete occlusion of a vessel with ischaemia (and likely infarction) being transmural
What is the pathophysiology of ACS?
- Acute thrombosis induced by rupture of atherosclerotic plaque
- Vasoconstriction
- Critical decrease in blood flow
- Clinical cascade
What is the stats regarding hospital mortality for NSTEMI and STEMI?
NSTEMI = 3-5% STEMI = 7%
What is more common, a STEMI or NSTEMI?
NSTEMI
What is the 6 month mortality for NSTEMI and STEMI?
NSTEMI = 13% STEMI = 12%
What are the clinical findings of unstable angina?
- prolonged angina at rest (>20mins)
- new onset of severe angina at rest
- angina that increases in frequency, longer in duration or lower in threshold
- Occurs after a recent MI
What can the ECG of a patient with unstable angina show?
- ST-segment depression
- T-wave inversion
- Can be normal
Are there any clinical biomarkers of unstable angina?
No
- No elevation in troponin or creatine kinase-MB
What are the treatment aims of unstable angina?
Focus on initial interventions and triage according to presumptive diagnosis
What can the ECG of a patient with NSTEMI show?
- ST-segment depression
- Transient ST-segment elevation
- T-wave inversion
- Can be normal
What are the clinical biomarkers of a patient with NSTEMI?
elevated troponin at presentation or several hours after NSTEMI
What are the treatment aims for NSTEMI?
- Relief of ischaemia
- Prevention of further thrombosis or embolism
- Stabilisation of haemodynamic status
What can the ECG initially show of a patient with STEMI?
STEMI?
- >20mins ST-segment elevation in 2 or more anatomically continuous leads
AND
- New LBBB
What can the ECG show over hours-days of a patient with STEMI?
- T-wave inversion
- Pathological Q-waves
What are the clinical biomarkers of a patient with STEMI?
elevated troponin and creatine kinase-MB
What are the treatment aims for a patient with STEMI?
- Percutaneous Coronary Intervention (PCI) within 120 minutes of first presentation
OR - Thrombolysis within 12 hours of symptom onset
In STEMI, what does a posterior MI show on the ECG?
- Anterior leads show ST depression
- Limb leads show ST elevation
In STEMI, how do you know the left coronary artery is occluded?
ST-segment elevation in leads I, aVL, V3-V6
These leads show the anterolateral portion of the heart
In STEMI, how do you know if the LAD is occluded?
ST-segment elevation in leads V1-V4
These leads show the anterior portion of the heart
In STEMI, how do you know if the Circumflex artery is occluded?
ST-segment elevation in leads I, aVL, V5-V6
These leads show the lateral portion of the heart
In STEMI, how do you know if the Right Coronary Artery is occluded?
ST-segment elevation in leads II, III, aVF
These leads show the inferior position of the heart
What are the symptoms of ACS?
- New onset of chest pain at rest lasting >15 mins
- High frequency chest pain
- High severity of chest pain
- Retrosternal chest pain radiating to the jaw, arm or neck
- Dyspnoea
- Nausea, vomiting, sweating
- Can be ‘silent’
- Common in elderly and diabetic patients
What is the first investigation you order for ACS?
ECG
- either in ambulance or within 10 minutes of arriving at hospital
Does a normal ECG exclude ACS?
NO
A normal ECG can be due to:
- Ischaemia in circumflex artery territory
- Isolated right ventricle ischaemia
- Transient LBBB or RBBB
1 and 2 are only detected using leads V7-V9, V3R and V4R
What other investigations should you order for ACS a part from an ECG?
- Cardiac Biomarkers
- Troponin I and T
- Creatine kinase-MB
- CXR
- Bloods
- FBC
- U&Es
- Serum creatine
- Blood Glucose
- Lipids
- Liver function tests
- Echocardiogram
What will the cardiac biomarkers show for NSTEMI and STEMI?
Raised troponin I and T
Raised Creatine kinase-MB
What will a CXR show after an MI?
Potentially:
- Cardiomegaly
- Pulmonary oedema
- Widened mediastinum
What will an echocardiogram show after an MI?
- Regional wall motion abrnormality (Part of the heart wall not thickening as well during systole)
- Depressed left ventricular function
- Decreased ejection fraction
What could a FBC show?
Haemoglobin and haematocrit measurements may help to evaluate secondary causes of MI:
- Acute blood loss
- Anaemia
Evaluate thrombocytopenia to estimate risk of bleeding
What could electrolytes show?
normal or deranged
- deranged - may predispose to cardiac arrhythmias
Why order liver function tests and serum creatine?
LFTs
- useful when considering treatment with drugs that undergo hepatic metabolism
Serum creatinine
- Clearance of renal creatinine is estimated to allow adjusting for renal cleared drugs
What are the risk factors for ACS?
- Male gender
- Increasing age
- Positive family Hx
- Hx of CAD
- Hypertension
- Diabetes
- Hyperlipidaemia
- Obesity
- Smoking
- Cocaine use
- Hypercholesterolaemia
What is the incidence of STEMI per annum?
5/1000
What is the initial treatment for chest pain?
- Nitrates GTN to relieve ischaemic pain - Morphine (and antiemetic) if pain continues - Antiplatelet - Aspirin 300mg STAT - Oxygen if SaO2 is <94%
MONA: M - morphine O - oxygen N - nitrates A - aspirin
What do you give a patient if they are allergic to aspirin?
- Clopidogrel - if no excessive bleeding risk
OR - Prasugrel
- Ticagrelor
For an NSTEMI/unstable angina what else would you give?
- Dual anti-platelet therapy
300mg Aspirin loading followed by 75mg o.d.
+ Clopidogrel (if no excessive bleeding risk)
OR Prasugrel
OR Ticagrelor - Anticoagulation
Fondaparinux 2.5mg o.d.
For NSTEMI, what would you do after giving the initial treatment (MONA)?
Calculate the GRACE score
What is the GRACE score?
Calculates ischaemic risk
Predicts the risk of future adverse CV events by predicting 6-month mortality
Which patients with NSTEMI have coronary angiography (with PCI if necessary)?
- Immediately if patient is unstable (hypotensive)
- Within 72 hours if GRACE score ≥3%
For an NSTEMI patient what would you give them before PCI?
Unfractioned heparin regardless whether they have received fondaparinux
For high risk patients with NSTEMI, what is the drug treatment pathway after a calculation a high-risk GRACE score?
B - Beta Blockers A - Aspirin 300mg T - Ticagrelor 180mg (or clopidogrel 300mg) M - Morphine titrated for pain A - Antigoagulant (fondaparinux or LMWH) N - Nitrites (GTN IV)
ACE inhibitors
When can you not give Beta Blockers?
When patient has:
- Cardiogenic shock
- Heart Failure
- Asthma
- COPD
- Heart block
What can you give instead of ACE inhibitors, if a patient does not tolerate them well?
Angiotensin II receptor blockers (ARBs)
What is the treatment pathway for STEMI patients?
Primary Percutaneous Coronary Intervention (PCI)
- Offered within 12hrs of symptom onset and if can be done within 120mins of medical contact
Thrombolysis
- If PCI cannot be offered within 120 mins
What happens after 12hrs of STEMI symptom onset?
If there is evidence of ongoing ischaemia - PCI
What drugs must be used with PCI?
Dual anti-platelet therapy
IV anticoagulant
- Bivilrudin (1st choice) and GPI
OR
- Unfractioned heparin and GPI
What happens if thrombolysis is unsuccessful?
Get PCI
What needs continual monitoring when a patient is in hospital for ACS?
- Exacerbations in pain/symptoms
- Pulse and BP
- Heart rhythm
- O2 sats by pulse oximetry
- Repeated ECG
- Checking if pain relief is effective
What are the most common complications post-MI?
DREAD
D - Death R - Rupture of heart septum or papillary muscles E - Edema (Heart Failure) A - Arrhythmia and Aneurysm D - Dressler's syndrome
What is Dressler’s syndrome?
It is a type of pericarditis
Inflammatory response from the immune system goes to heart just beneath the pericardium due to tissue necrosis
What is secondary prevention after an MI?
6 A's: Aspirin (75mg once daily) Another antiplatelet for 12 months Atorvastatin (80mg once daily) ACE inhibitor (ramipril) Atenolol (beta blocker) Aldosterone antagonist (for those with HF)
What can you give if beta blockers are contraindicated?
Calcium channel blockers
What is offered on the cardiac rehabilitation programme?
- Exercise
- Health education
- Advice on work
- Advice on travel
- Stress management
