Cardiology: Acute Coronary Syndrome + Stable Angina Flashcards
What investigations do you do in someone presenting with symptoms of an ACS?
1) 12 lead ECG
2) Troponin
3) Bloods
4) Consider CXR
5) Consider CTPA/ D-dimer if suspicious of PE
What are the two most important investigations to do in someone presenting with symptoms of an ACS?
12 lead ECG + troponin
How do you diagnose a STEMI?
Raised troponin + persistent ST elevation OR new LBBB + cardiac chest pain
What are the types of ACS?
1) STEMI
2) NSTEMI
3) Unstable angina
What are the diagnostic features of NSTEMI?
Raised troponin + normal/abnormal ECG but NO ST elevation + cardiac chest pain
What are the diagnostic features of unstable angina?
Normal troponin + normal/abnormal ECG changes + cardiac chest pain
What is acute coronary syndrome?
A constellation of symptoms and clinical findings which results from impaired cardiac perfusion at rest
What is the difference between myocardial infarction and angina?
Myocardial infarction is caused by underperfusion of the myocardium leading to death of myocardial tissue - it is distinguished from angina by this death of tissue
What are the non-modifiable risk factors for ACS?
1) Age
2) Male sex
3) Family history
4) Ethnicity - particularly South Asians
What are the modifiable risk factors for ACS?
1) Smoking
2) Hypertension
3) Hyperlipidaemia
4) Hypercholesterolaemia
5) Obesity
6) Diabetes
7) Stress
8) High fat diets
9) Physical inactivity
What causes STEMI?
Complete occlusion of a coronary artery
What causes NSTEMI?
Severe but incomplete stenosis/occlusion of a coronary artery
What are other causes of NSTEMIs?
Lack of cardiac oxygenation for other reasons:
1) Severe sepsis
2) Hypotension
3) Hypovolaemia
4) Coronary artery spasm
- These cases might not respond to or need conventional treatment
Why might a suspected NSTEMI not respond to conventional treatment?
The NSTEMI might be due to lack of cardiac oxygenation for other reasons:
1) Severe sepsis
2) Hypotension
3) Hypovolaemia
4) Coronary artery spasm
How does ACS typically present?
Chest pain/tightness:
S - central/left sided
O - sudden
C - crushing/chest tightness
R - left arm, neck and jaw
A - nausea, sweating, clamminess, SOB ± vomiting/syncope
T - constant
E - worsened by exercise/exertion and may be improved by GTN
S - often extremely severe
What are atypical presentations of ACS?
1) Epigastric pain
2) No pain
3) Acute breathlessness
4) Palpitations
5) Acute confusion
6) Diabetic hyperglycaemic crises
7) Syncope
Which patients are more likely to have atypical presentations of ACS with no pain?
Elderly + diabetes
What are cardiac non-MI causes of chest pain?
1) Myocarditis
2) Pericarditis
3) Cardiomyopathy
4) Valvular disease
5) Cardiac trauma
What are pulmonary non-MI causes of chest pain?
1) PE
2) Pneumonia
3) Pneumothorax
What is a vascular cause of chest pain?
Aortic dissection
What are GI causes of chest pain?
1) Oesophageal spasm
2) Oesophagitis
3) Peptic ulcer
4) Pancreatitis
5) Cholecystitis
What are MSK causes of chest pain?
1) Rib fracture
2) Costochondritis
3) Muscle injury
4) Herpes zoster
What do you you not need if you see persistent ST elevation or new LBBB on ECG?
Troponin - clear STEMI
How do you diagnose STEMI?
1) ST segment elevation > 2mm in adjacent chest leads
2) ST segment elevation > 1mm in adjacent limb leads
3) New LBBB with chest pain or suspicion of MI
How do you diagnose NSTEMI?
Two of:
1) Cardiac chest pain
2) Newly abnormal ECG which is NOT ST-elevation
3) Raised troponin (with no other reasonable explanation)
Which is the single most important investigation in a patient who may have an MI and why?
ECG - defines immediate management and should not be delayed for any other investigation, if an ECG shows STEMI then troponin is essentially irrelevant and the patient requires immediate treatment
When does troponin need to be performed?
At least 3 hours after pain starts (may also need to be repeated 6-12h after the start of pain if initial result is equivocal)
Which bloods do you do in suspected MI?
1) Troponin
2) Renal function
3) Blood glucose
4) Lipid profile
5) FBC & CRP - to rule out infectious causes of chest pain
6) D-dimer - may be used in appropriate patients to rule out PE
Why would you do a CXR in MI?
1) Looking for pulmonary causes of chest pain
2) Looking for pulmonary oedema (as a complication of MI)
What might you see on ECG in NSTEMI?
T wave abnormalities e.g. inversions in the same vascular territories as STEMIs - however changes can also often not include all the specific leads for territory in NSTEMI
What is troponin?
A myocardial protein released into the bloodstream when cardiac myocytes are damaged
When do serum troponin levels typically rise?
3 hours after MI begins
What are non-ACS causes of a raised troponin?
1) Pericarditis
2) Myocarditis
3) Arrhythmias
4) Defibrillation
5) Acute heart failure
6) Pulmonary embolus
7) Type A aortic dissection
8) Chronic kidney disease
9) Prolonged strenuous exercise
10) Sepsis
How do you manage STEMI?
MONAC
1) IV morphine/diamorphine
2) Oxygen - aiming for sats > 90%
3) Nitrates - sublingual GTN spray (for symptom relief)
4) Aspirin PO 300mg (loading dose)
5) Clopidogrel 300mg (or ticagrelor 180mg)
6) Primary percutaneous coronary intervention (PPCI) if eligible
Remember that (particularly in STEMI) time is heart therefore urgent treatment, escalation and delivery of PPCI is critical to good outcomes
What should be added onto STEMI treatment if the patient is going on to have PCI?
1) Prasugrel (if not on anti-coagulation) or
2) Clopidogrel (if on anti-coagulation)
Which dose of aspirin do you give in STEMI?
300mg PO
Which dose of clopidogrel do you give in STEMI?
300mg
Why do you give IV morphine in (N)STEMI?
Analgesia + causes vasodilation reducing preload on the heart
Which patients are eligible for PCI?
1) Present within 12 hours of onset of pain AND
2) Are < 2 hours since first medical contact
How do you manage a STEMI in a patient who is stable but PCI is not available within 2 hours?
Thrombolysis (alteplase)
How do you manage a patient presenting with STEMI > 12 hours after symptom onset?
Pharmacological management
How to you manage NSTEMI?
BOATMAN
1) Base the decision about angiography and PCI on the GRACE score
2) Oxygen - if sats drop
3) Aspirin 300mg stat
4) Ticagrelor 180mg stat (clopidogrel if high bleeding risk or prasugrel if having angiography)
5) Morphine IV
6) Antithrombin therapy - fondaparinux (unless high bleeding risk or immediate angiography)
3) Nitrates - sublingual GTN spray
What dose of ticagrelor do you give in NSTEMI?
180mg
When would you give clopidogrel over ticagrelor in NSTEMI?
High bleeding risk
When would you give prasugrel over ticagrelor in NSTEMI?
If they are having immediate angiography
When would you NOT give fondaparinux in NSTEMI?
High bleeding risk OR immediate angiography