Acute MI Flashcards
what are the criteria for the diagnosis of ST elevation on an ECG?
- there must be at least 1mm elevation in two adjacent limb leads
- there must be at least 2mm elevation in at least 2 contiguous (touching) precordial leads e.g. V4 and V5
- There must be new onset bundle branch block
what are three ECG CHANGES in acute STEMI?
- ST elevation (occurs in first few hours)
- T wave inversion (occurs on first day)
- Q waves (develops later and is a sign of previous MI)
what are the inferior leads?
-Lead II
-Lead III
-aVF
(the ones at the bottom left of the ECG)
what are the anterior leads?
V1–> V6
what are the anteroseptal leads?
V1–> V4
what are the anterolateral leads?
- lead I
- aVL
- V1 –> V6
what are the 2 anterior leads?
V1, V2
what are the 2 septal leads?
V3, V4
what are the 4 lateral leads?
V5, V6, Lead I, aVL
what can be used to diagnose MI?
- cardiac enzymes and protein markers (may be normal at time of presentation so don’t wait for results)
- use creatinine kinase and troponin
what is thrombolysis?
a way of breaking up the clot and re-establishing blood flow. Deliver within 2 hours. Results after 12 hours are poor
re-perfusion therapies?
-thrombolysis
-PCI (followed by coronary angioplasty)
-CABG
(optimal reperfusion time for PCI is within 90 minutes)
indications for reperfusion therapy?
- chest pain >20 minutes and <12 hours
- ECG changes with acute ST elevation OR new left BBB
- no contraindications
what is the early treatment of STEMI?
- Morphine (diamorphine) and anti-emetic
- Oxygen if hypoxic
- Nitrates (GTN if BP>90mmHg)
- Aspirin
- Clopidogrel
- primary angioplasty within 40 minutes
- thrombolysis if angioplasty unavailable within 90 minutes
what is seen on ECG that diagnoses NSTEMI?
- the ECG may be normal
- if ECG changes are present –> indicative of poor outcome
- may be ST segment DEPRESSION - a marker of cardiac ischaemia
- may be T wave inversion in the absence of ST elevation
