Heart Attack Flashcards
What are the characteristics of stable angina?
- fixed stenosis
- demand led ischaemia
- predictable
- safe
What advice is given to patients having an angina attack?
‘stop, sit spray’ - have one spray of GTN leave 5 mins and spray again - if pain persists call 999
Define acute coronary syndrome
any acute presentation of coronary disease
- unstable angina
- acute non-STEMI
- STEMI
How does it differ from stable angina?
- dynamic stenosis
- supply led ischaemia
- unpredictable
- dangerous
Name six factors affecting plaque rupture
- lipid content of plaque
- thickness of fibrous cap
- sudden changes in pressure
- bending/twisting of artery
- plaque shape
- mechanical injury
What is the result of an occlusion in a stemi?
everything downstream from the occlusion starts to die
Can heart muscle regenerate?
Nope - it begins to scar
What is the result of scarring?
Dilation & aneurysm –> heart failure
Describe a classical presentation of a heart attack
Severe, central crushing chest pain radiating to the jaw and left arm. Associated with sweating and nausea
What must be present to diagnose a STEMI from an ECG?
> 1mm ST elevation in 2 adjacent limb leads
>2mm ST elevation in 2 contiguous precordial leads
What other changes may be seen on an ECG?
Q wave formation, T wave inversion
Other than ECG what other test can be done on a patient with a suspected MI?
Protein markers & enzymes
Troponin & Creatinine Kinase
What are the three types of troponin?
Troponin C - binds to calcium
Troponin I - binds to actin (deactivates actin after contraction)
Troponin T - facilitates contraction by binding to tropomyosin complex
In ischaemia what happens to troponin levels?
They rise 2-4 hours after an MI
What does elevated troponin signify?
Cardial necrosis
What is the early treatment for a suspected MI?
Morphine ( and anti-emetic) Oxygen Nitrates Aspirin 300mg (chewable) \+Clopidogrel 300mg
When is thrombolysis administered?
If it is going to take more than 2 hours to get the patient to the cath lab for PCI
What is an alternative to clopidogrel?
Ticegralor 180mg
Name an anti-emetic
Metaclopramide
Name four types of complications of an MI
- Death
- Arrhythmic complications
- Structural complications
- Functional complications
What is the main, life threatening arrhythmic complication?
Ventricular fibrillation
Name three structural complications
- cardiac rupture (left ventricle)
- ventricular septal defect
- mitral valve regurgitation
Name three functional complications
- acute ventricular failure
- chronic cardiac failure
- cardiogenic shock
What are the four classes of the killip classification?
Risk of mortality I - no signs of HF 6% II - creps <50% 17% III - creps >50% 38% IV - cariogenic shock 81%
State the routine observations done on a patient who has had a recent MI
- Pulse & BP
- cardiac monitor
- heart sounds
- murmurs
- crepitations
- urine output
When is a patient deemed to have a NSTEMI?
When the markers are high but there is no ST elevation on ECG
What are the two key parts of the pathophysiology of UA and NSTEMI?
Thrombosis and vasoconstriction leads to reduced coronary blood flow
What is the management for a patient with a NSTEMI?
Urgent revascularisation for patients at high risk
- anti platelet
(aspirin 300mg then 75mg/day for life, clopidogrel 300mg then 75mg/day for 12 months)
- antithrombin
(LMWH, glycoprotein IIb/IIIa antagonists)
- beta blockers, nitrates, calcium channel blockers, ACE inhibitor, statins)
When is thrombolysis contraindicated?
- surgery
- bleeding/trauma
- warfarin
- haematoma
