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
Which scoring system is used to make a decision about angiography and PCI in NSTEMI?
GRACE score
How is the GRACE score used?
The GRACE score gives a 6 month probability of death after having an NSTEMI
1) < 3% = low risk
2) > 3% = medium-high risk
3) Patients at medium or high risk are considered for early angiography with PCI (within 72h)
How do you manage a patient with NSTEMI at medium or high risk?
Early angiography + PCI (within 72h)
How do you manage clinically unstable patients with STEMI or NSTEMI?
Immediate angiography
Which drug is contraindicated in patients with hypotension?
GTN
What do patients require after initial management of MI once they are stable?
1) Echo - to assess functional damage to the heart, esp. LV function
2) Cardiac rehabilitation
3) Secondary prevention medications
How do you manage unstable angina?
Similar to that of NSTEMI with aspirin for all patients and fondaparinux and early angiography for those at high risk
Which imaging investigation is needed post-MI?
Echo
Why is an echo needed post-MI?
To assess functional damage to the heart, esp. left ventricular/systolic function and any evidence of heart failure (should be treated)
Which medications are given for secondary prevention post-MI?
1) Aspirin 75mg OD lifelong
2) Antiplatelet - ticagrelor or clopidogrel for 12 months (depends on type of stent inserted)
3) Atorvastatin 80mg ON
4) ACEi - ramipril
5) Beta blocker - bisoprolol
6) Aldosterone antagonist for those with clinical heart failure e.g. eplerenone titrated to 50mg OD
What type of drug is aspirin?
Anti-platelet
What does of aspirin is given as post-MI management?
75mg OD
How long does aspirin need to be taken post-MI?
Lifelong
What does of atorvastatin is given post MI?
80mg (high dose)
How long is the second antiplatelet taken post-MI?
12 months - clopidogrel 75mg OD or ticagrelor 90mg OD
What should patients treated for MI without angiography be considered for?
Ischaemia testing - to assess for inducible ischaemia
What are complications of MI?
1) Ventricular arrhythmia
2) Recurrent ischaemia/infarction/angina
3) Acute mitral regurgitation
4) 2nd or 3rd degree heart block (common)
5) Cardiogenic shock
6) Cardiac tamponade
7) Ventricular septal defects
8) Left ventricular thrombus/aneurysm
9) Left/right ventricular free wall rupture
10) Dressler’s syndrome
11) Acute pericarditis
When can ventricular arrhythmias occur post-MI?
1) As a consequence of MI
2) During cardiac catheterisation
3) After reperfusion
How do you manage ventricular arrhythmias post-MI?
1) Most are short-lived and self-resolve
2) If sustained VT or VF occurs - should be treated as per ALS protocols
What are the features of recurrent ischaemia/infarction/angina post-MI?
1) Occasionally inserted stents can thrombose requiring reintervention
2) New infarcts can occur in different vascular territories (this is less likely now with PCI where all territory are imaged during the procedure)
3) Angina + chest pain can continue for some time after an MI and is more common in NSTEMI patients
Why can congestive heart failure occur post-MI?
As a consequence of impairment of heart muscle function secondary to ischaemia
How should congestive heart failure be treated post-MI?
As any other acute heart failure - ventricular function may improve over months as the heart muscle recovers
After which type of infarct is heart block more common?
Following inferior infarcts - bc RCA supplied the SA node
How can heart block be treated post-MI?
1) Simple observation - as many will revert back to sinus rhythm
2) Transcutaneous/venous pacing - if symptomatic
3) Permanent pacing - if failing to resolve
After which type of MI can left ventricular aneurysm occur and what happens?
Aneurysm can occur following an anterior MI where the myocardium can be susceptible to wall stress leading to an aneurysm
How does left ventricular thrombus present?
May be silent, cause arrhythmias or embolic events
How is left ventricular aneurysm diagnosed?
1) Definitively on ECHO
2) ECG - may show persisting ST elevation
What are the features of left ventricular thrombi?
1) Thrombus can form either within an above described aneurysm or around hypokinetic regions of the myocardium
2) Thrombi can embolise causing complications e.g. stroke, acute limb ischaemia and mesenteric ischaemia
What is left/right ventricular free wall rupture post-MI?
1) Necrosis of the free walls of either ventricle can lead to rupture allowing blood into the pericardial space
2) This leads to a rapid tamponade
3) Normally leads to cardiac arrest/death within seconds
What is treatment for left/right ventricular wall rupture?
Pericardiocentesis + surgery (but prognosis is v poor)
Which valve disorder can occur post-MI?
Mitral regurgitation
Why does acute mitral regurgitation occur post-MI?
Bc of papillary muscle rupture - poor prognosis
How does acute mitral regurgitation post-MI present?
1) Pansystolic murmur - loudest at apex
2) Severe + sudden heart failure
How is acute mitral regurgitation post-MI diagnosed and treated?
Echo - may require surgical correction
What are the features of ventricular septal defect/rupture?
1) Interventricular septal rupture is a short-term complications of myocardial infarction
2) Rupture caused by an anterior infarct is generally apical and simple
3) Rupture caused by an inferior infarct is generally basal and more complex
4) Without reperfusion, septal rupture typically occurs within the first week after the infarction
How does ventricular septal defect/rupture present?
1) SOB
2) Chest pain
3) Heart failure
4) Hypotension
5) Harsh, loud pan-systolic murmur along the left sternal border
6) Palpable parasternal thrill
What does a harsh, loud pan-systolic murmur along the left sternal border indicate?
Ventricular septal rupture/defect (post-MI)
How do you diagnose ventricular septal rupture/defect?
Echo
How do you manage ventricular septal rupture/defect?
Emergency cardiac surgery
What is Dressler’s syndrome?
Post-infarction pericarditis
How does Dressler’s syndrome present?
Persistent fever + pleuritic chest pain 2-3 weeks-few months after MI
- Can also present with features of pericardial effusion (has become relatively uncommon since introduction of PCI)
Is pericarditis immediately following MI Dresser’s syndrome?
No
How do you manage Dressler’s syndrome?
1) High dose aspirin
2) Symptoms usually resolve after several days
What are post-MI signs on ECG?
1) Pathological Q waves in relevant leads
2) T wave inversion
What is the chest pain like in angina?
Typical = 3 features:
1) Constriction like pain in chest/neck/arm/jaw
2) Brought on by physical activity
3) Alleviated by rest or GTN within minutes
Atypical = 2 out of 3 features
What are first-line investigations for stable angina once atypical or typical angina pain is suspected?
1) ECG
2) Routine bloods e.g. FBC to exclude anaemia
3) TFTs - to exclude hyperthyroidism which can exacerbate angina
Which two non-cardiac conditions can exacerbate angina?
Anaemia + hyperthyroidim
What is the first line diagnostic investigation for stable angina?
CT coronary angiography
When is CT coronary angiography indicated?
1) Atypical or typical angina pain
2) ECG showing ischaemic changes in chest pain with < 2 angina features
What are second line functional imaging investigations that can be done if CT coronary angiography is inconclusive in stable angina?
1) Myocardial perfusion SPECT
2) Stress Echo
3) MRI for regional wall motion abnormalities
What is the third line investigation of stable angina if there are inconclusive results from non-invasive testing?
Coronary angiogram
What is conservative management in angina?
Optimising risk factors for CVD:
1) Smoking cessation
2) Glycaemic control
3) Hypertension
4) Hyperlipidaemia
5) Weight loss
6) Alcohol intake
Prevention medication - aspirin, statin
What is the first line management if stable angina?
1) Lifestyle measure (conservative)
2) Prevention medication - aspirin, statin (conservative)
3) GTN + beta-blocker OR rate-limiting CCB e.g. verapamil
What is first line medical management in stable angina?
GTN + beta-blocker OR rate-limiting CCB e.g. verapamil/diltiazem
What advice needs to be given to patients starting GTN?
1) Side effects = headaches, flushing, dizziness
2) Take another dose if pain has not subsided after 5 mins
3) Emergency help should be sought if the pain has not subsided after 2 doses of GTN - may indicate acute coronary syndrome
After how many doses of GTN should a patient call the ambulance bc of the risk of ACS?
2 doses ineffective
What is first line medical management of stable angina if a patient is unable to tolerate a beta blocker?
Rate-limiting CCB e.g. verapamil
What is first line medical management of stable angina if a patient is unable to tolerate a Rate-limiting CCB?
Beta blocker
Which medications should be considered for first line stable angina medical management if the patient is unable to tolerate or is contraindicated to a beta blocker or rate-limiting CCB?
1) Long-acting nitrate e.g. Isosorbide Mononitrate
2) Ivabradine
3) Nicorandil
4) Ranolazine
What is second-line medical management for stable angina?
Beta blocker AND long-acting dihydropyridine CCB e.g. amlodipine
What are the rate-limiting/non-dihydropyridine calcium channel blockers?
Verapamil, diltiazem
What are the long-acting dihydropyridine calcium channel blockers?
Amlodipine, nifedipine extended release
What is third line management of stable angina?
1) Coronary angiography - unless contraindicated as PCI may be required
2) Consider ACEi for patients with diabetes and hypertension
Which two medications do you not prescribe together for treatment of stable angina?
Beta blocker + dihydropyridine CCB e.g. bisoprolol and amlodipine
When should a third medication be added to treatment of stable angina?
If the patient is symptomatic despite 2 anti-anginal drugs
What are revascularisation treatments?
CABG or PCI
When should patients with stable angina be considered for revascularisation (PCI or CABG) - indications for CABG?
Symptoms are not satisfactorily controlled on optimal medical treatment AND
1) There is complex 3 vessel disease OR
2) There is significant left main stem stenosis
What is the advantage of PCI over CABG?
More cost effective
In which patients does CABG have a mortality advantage over PCI?
1) > 65 years
2) Diabetes
3) Anatomically complex 3 vessel disease - with or without left main stem stenosis
