ACS and AMI - Presentation and Investigation Flashcards
Describe the pathophysiology of MI
STEMI;
- Plaque rupture –> complete occlusion of coronary lumen and distal MI
- Proximal occlusion more damaging
- Vasospasm and vasoconstriction
- Pap muscle rupture = acute MR
- Occlusion of AV nodal artery = complete heart block
Know the clinical presentation of MI
NSTEMI;
- Myocardial ischaemic symptoms at rest
Know the clinical presentation of MI
NSTEMI;
- Myocardial ischaemic symptoms at rest
- May look well
- Check HR, BP, murmurs, crackles
- Atypical presentation more likely in women, elderly, diabetics
Symptoms;
- SOB +/- signs of HF
- Nausea and vomiting +/- autonomic symptoms
- Epigastric pain =/- onset of indigestion
Describe the characteristic ECG changes and other diagnostic aids for MI
- May be normal
- ST segment depression
- Transient ST segment elevation (STEMI)
- T-wave inversion
- Serial ECGs necessary to detect change
Describe the use of biomarkers in the diagnosis of NSTEMI
- Cardiac troponin, usually undetectable
- Good for triage
- Elevated cTn indicates high risk
- May not be ACS, only atherothrombosis
Describe the immediate treatment of NSTEMI
- ABCDE then MONA
- Morphine
- Oxygen
- Nitroglycerine (GTN spray or tablet)
- Aspirin 300mg orally (crush/chew)
Describe the secondary prevention treatment of MI
- Control risk factors and co-morbidities
Anti-platelet;
- All should get aspiring + ADP receptor blocker (clopidogrel/pasugrel/ticagrelor)
- For 1 year following ACS
- Clopidogrel: 300mg, 75mg daily
Anti-thrombotic;
- IV UFH
- Or LMWH: better outcome, easier to administer (subcutaneous), no monitoring
Other;
- Beta blocker
- Statin
- ACEi: always if LVD, controversial if normal
Describe the selection of optimal repercussion strategy in STEMI
- Primary PCI better
- Most effective 120-150mins after call
- Use if; D-B <90mins, <3hrs since symptoms onset, cardiogenic shock, HF, high bleeding risk, Diagnosis uncertain
- 2nd best to PCI
- Most effective within 90mins
- Use if: D-B >90mins, >3hrs since symptoms onset
Describe the the relationship between fibrinolysis and bleeding
Increased risk of bleeding and haemorrhage in;
- Age >75
- Female
- Previous stroke
- Low body weight
- High BP
- High INR
- Chronic kidney disease, elevated creatinine
Define sudden cardiac death
- 80% that survive have VT or VF
- Often due to occlusion of LAD in younger patients
- Not all SCDs are ACS events
Describe the complication of free wall rupture in MI
- LAD area most common
- Occurs at edge of infarcted area
- Leads to haemopericardium and acute tamponade
- Elderly, women, HBP and anterior MI
- Urgent echo, pericardiocentesis, drainage
- If survive, immediate surgery (rare)
What is echo used for in MI?
Myocardial dysfunction;
- Size of wall motion abnormality, how kinetic, contractility
- Presence and degree of MR (inferior MI)
- Presence of mural thrombus (anterior-apical MI)
Define ventricular fibrillation
- Defibrillation only treatment
- Tends to rapidly deteriorate into asystole
Describe the complication of papillary muscle rupture in MI
- Which muscle ruptures depends on type of MI
- Complete transection incompatible with life
- Sudden SOB, chest pain, autonomic activation
- Shock, tachycardia, pulmonary oedema, rightt heave, thrill, elevated JVP, harsh systolic murmur
- Echo, cath lab
- Immediate surgery
Describe clopidogrel and prasugrel
- 300mg, 75mg daily
- Activated by Cyp 2C19, 13% have low levels
- Prasugrel more rapid and consistent anti-platelet
