Acute coronary syndromes (CV) Flashcards
What does ACS refer to?
A spectrum of acute myocardial ischaemia and/or infarction
What are the types of ACS? (3)
- unstable angina
- NSTEMI
- STEMI
How can you remember LBBB?
WiLLiaM
- W in V1
- M in V5/V6
What are some causes of LBBB? (1 + 5)
Always pathological:
- MI
- hypertension
- aortic stenosis
- cardiomyopathy
- hyperkalaemia
What does new onset LBBB prompt?
Investigation for ACS –> troponin levels
What type of MI is LBBB most likely to be?
Anterior-anteroseptal MI
How can you remember RBBB?
MaRRoW
- M in V1
- W in V5/V6
What are some causes of RBBB? (3)
- can be normal - more common with increasing age (vs LBBB - always pathological)
- RVH
- chronically increased RV pressure (cor pulmonale)
How can you differentiate between LBBB and RBBB on ECG?
- LBBB: WiLLiaM (W in V1, M in V5/V6)
- RBBB: MaRRoW (M in V1, W in V5/V6)
What does ACS result in?
Angina pectoris due to partial/total occlusion of a coronary artery due to plaque rupture (thrombosis), embolus or dissection –> necrosis
What are some clinical features of ACS? (10)
- acute central chest pain
- dull, squeezing tightness
- radiates to left chest, arm, shoulder, neck, jaw
- crushing
- dyspnoea (SOB)
- sweating
- pallor
- nausea and vomiting
- palpitations
- syncope and dizziness
What do you check on examination of ACS to rule out aortic dissection?
Check both radial pulses
What may develop and be seen on examination in later stages of ACS?
A pericardial friction rub or peripheral oedema
What is an atypical presentation of ACS?
Painless in elderly and diabetics - presentation includes syncope, pulmonary oedema, epigastric pain and vomiting
How can an MI cause mitral regurgitation and what would you see on examination?
- due to rupture of the tendinous cords that usually hold the valve in place
- flash pulmonary oedema seen in patient
What is a complication of MI that causes S3 + S4 heart sounds?
- left ventricular aneurysm - due to significant damage to part of the ventricular muscle –> weakening
- patients present with tiredness and breathless
- persistent ST elevation on ECG (still there from previous MI)
- can lead to left ventricular thromboembolism –> embolic stroke or other systemic embolisms
What do S3 and S4 heart sounds suggest?
- S3 - LV is larger than normal (as S3 represents sloshing of blood into large ventricle during diastole)
- S4 - LV is stiffer than normal (as S4 represents the forceful atrial push of blood against a hard ventricular wall)
- therefore S3+S4 = LV is larger than usual, with stiff walls and causing pulmonary congestion
What do you see on ECG of left ventricular aneurysm (complication of MI)?
- persistent ST elevation in V1-6 on ECG
- as fibrosis and dead tissue is not able to properly move as expected
What are the symptoms of left ventricular free wall rupture post-MI? (3)
- raised JVP
- pulsus paradoxus
- diminished heart sounds
How do we treat left ventricular free wall rupture post-MI?
Urgent pericardiocentesis and thoracotomy
Compare unstable angina vs NSTEMI vs STEMI.
- unstable angina - no biochemical evidence of myocardial damage, no raised troponin
- NSTEMI - ischaemic ECG changes, elevation of troponin/CK
- STEMI - ST elevation on initial ECG, elevation of troponin/CK, complete occlusion, transmural infarction
What are the risk factors for ACS? (10)
- male
- diabetes mellitus
- Fx
- hypertension
- hyperlipidaemia
- smoking
- age
- obesity
- sedentary lifestyle
- cocaine use
What are the 1st-line investigations for ACS? (5)
- 12-lead ECG - best initial test to differentiate STEMI & NSTEMI
- cardiac biomarkers - troponin & CK-MB
- bloods
- CXR
- exercise ECG (patients with troponin -ve ACS or stable angina with high pretest probability of coronary heart disease)
What is seen on an ECG in NSTEMI? (2)
- ST depression
- T wave inversion
- (transient ST elevation)
What is seen on an ECG in STEMI? (5)
- persistent (>20min) ST elevation in 2+ contiguous leads:
- leads V2-3: men<40=2.5mm, men>40=2mm, women=1.5mm
- 1mm in other leads (II, III, avF, aVL)
- new LBBB (WiLLiaM)
- hyperacute T-waves
- T-wave inversion
- pathological Q-waves