Clinical coronary conditions Flashcards
What is the difference b/w Acute MI and unstable angina?
Acute MI
- Usually severe/ fully occluded artery via ruptured plaque or thrombus
- Muscle necrosis – Positive Enzymes
- Complications
– VF
– Sudden death
– Heart failure - due to decompesation from hypertrophy of failing heart
– Cardiogenic shock - massive loss in cardiac muscle leading to low perfusion
– Death
Unstable Angina
- Narrowed artery – or transient occlusion – or occlusion with collaterals
- No muscle necrosis – Normal Enzymes
- No mortality
- May go on to AMI & complications & death
What are the early interventions for MI?
_Reperfusion: _
Thrombolysis (IV) - but risk of haemorrhage
- Streptokinase
- Tissue Plasminogen activator
Percutaneous Coronary Intervention (PCI)
-coronary artery balloon stent
What are the groups of leads on an ECG and what do they show?
Inferior leads - suggest RCA occlusion
II, III, aVF
Anterior leads - suggest LAD occlusion
V1-5
Lateral leads - suggest circumflex A occlusion
I, aVL, V6
What are the clincal differences b/w a STEMI and a NSTEMI?
STEMI
– Can diagnose infarction in ED
– Can initiate early reperfusion treatment
– Usually larger infarcts, more complications
– Usually major artery occlusion
NSTEMI
– ST/T changes or normal ECG
– Cannot definitely diagnose infarction until enzymes positive, may be angina or non cardiac pain
–Too late for early reperfusion
– Smaller artery, partial or transient occlusion
What causes ST elevation in MI?
MI causes changes in AP between the endocardium and epicardium
- conduction delay b/w endcardium and epicardium
- current flows from endocardium -> epicardium
- ECG electrode is outside heart and ‘sees’ current flowing towards it during the ST segment, hence it records a positive voltage reading
