31 Flashcards
Cardiorespiratory
Epidemiology of ACS
Most common cause of death in the UK (1/5 men, 1/6 women).
More common in men.
Mortality equal in both sexes.
Increases with age.
Increased in South Asians.
Risk factors of ACS
Modifiable: smoking, diabetes, metabolic syndrome, hypertension, obesity, hyperlipidaemia, physical inactivity
Non-modifiable: male, increased age, FHx of premature CHD, premature menopause, south Asian
Definition of ACS
STEMI, NSTEMI and unstable angina
Symptoms of ACS
Central or epigastric chest pain, >15 minutes.
Radiates to arms, shoulders, neck or jaw.
- Sweating.
- Nausea and vomiting.
- Collapse/syncope.
- Dyspnoea.
- Fatigue.
- Palpitations.
Atypical presentation is seen in women, older men, diabetics and ethnic minorities - e.g. abdominal discomfort, jaw pain, altered mental state.
Signs of ACS
Tachycardia (sympathetic), Hypotension, Pallor, Sweating, Vomiting, Bradycardia (vagal), Pale, cool, clammy, Cold peripheries, 3rd heart sound, Oliguria, Narrow pulse pressure, Raised JVP, Lung crepitations.
Diagnostic criteria for MI
Detection of rise and/or fall of troponin and at least one of:
- Symptoms of ischaemia
- ECG changes
- Imaging evidence of new loss of myocardium or wall motion abnormality
Causes of MI
Atherosclerosis,
Infected cardiac valve,
Coronary occlusion secondary to vasculitis,
Coronary artery spasm.
Cocaine use.
Congenital coronary abnormality,
Coronary trauma,
Raised O2 requirement (hyperthyroid),
Decreased oxygen delivery (severe anaemia)
Investigations for ACS
Observations - stabilise
FBC - anaemia, CRP, ESR
U+Es - potassium and electrolytes
Lipid profile
Troponin
(can use CK-MB or myoglobin)
ECG (ST elevation, Q waves, T wave inversion)
ABG - high lactate and hypoxia
Echo for extent of infarction
Angiography
Myocardial perfusion scintigraphy (SPECT)
Cardiac enzymes
Troponin
- Increases within 3-12 hours from pain onset, peak at 48 hours, returns to baseline in 5-14 days
- Measure at presentation and 10-12 hours after onset
- T binds to tropomyosin, I binds to actin, C bind to calcium
Myocardial muscle creatine kinase (MB-CK) - Increase within 3-12 hours, peak at 24 hours, baseline within 3 days. Not as sensitive or specific.
Myoglobin - most sensitive early marker
Causes of raised troponin
ACS Congestive heart failure Sepsis PE CKD Myocarditis
ECG changes in anterior STEMI
Which artery is occluded?
LAD
V3-V4 (septal may be involved V1-V2)
Reciprocal ST depression in III and AVF
ECG changes in inferior STEMI
Which artery is occluded?
80% R coronary, 20% L circumflex
ST elevation, ST depression, T wave inversion, Q waves
II, III, aVF
ECG changes in lateral STEMI
Which artery is occluded?
V5-V6
1st diagonal branch of LAD or obtuse branch of L circumflex
Management for STEMI
- GTN
- Opioids
- 300mg aspirin
- Supplemental O2 if hypoxic
- PCI if able within 12 hours of onset
- Fibrinolysis if not - alteplase, reteplase or streptokinase.
Secondary prevention - ACEi, aspirin, 2nd anticoagulant (usually NOAC), beta blocker, statin.
Management of NSTEMI
- GTN
- Opioids
- 300mg aspirin
- Supplemental O2 if hypoxic
- Fondaparinux or unfractionated heparin within 24 hours
GRACE risk assessment
- Lowest risk - aspirin only (no angio)
- Low risk - aspirin + clopidogrel + consider angio
- High risk - aspirin + clopidogrel + urgent coronary angiography
Secondary prevention:
- ACEi
- Aspirin, + 2nd antiplatelet
- Beta blocker
- Statin
When is a coronary artery bypass graft (CABG) required?
Failed PCI (occlusion not amendable or refractory symptoms).
Cardiogenic shock.
Mechanical complications (rupture, mitral regurgitation).
Multivessel disease
What is the secondary prevention post ACS?
Aspirin +/- clopidogrel
Beta blocker
ACE inhibitor - check GFR and BP prior
Statin
Stop smoking, lower cholesterol, lower weight, increase exercise
Complications post-MI
Angina Re-infarct Heart failure Cardiogenic shock Valve dysfunction Cardiac rupture Arrhythmia
PE
Pericarditis
Depression
Epidemiology of angina
8% men, 3% women aged 55-64,
14% men, 8% women over 65
Increased in South Asian and Afro-Caribbean
Increasing age
Risk factors of angina
FHx Metabolic syndrome Smoking Diabetes Obesity Decreased exercise Hypertension Hyperlipidaemia Past CHD
Symptoms of angina
Constricting/heavy discomfort to the chest, jaw, neck, shoulders, or arms.
- Nausea
- Fatigue
- Dyspnoea
- Sweating
- Dizziness
“Stable angina:
- Symptoms brought on by exertion
- Relieved within 5min by rest or GTN
Unstable angina:
- Occurs even at rest
- May not be relieved by rest or GTN”
Different types of angina?
Stable - precipitated by predictable factors.
Unstable - symptoms occur at rest and occur at any time.
Refractory - symptoms cannot be controlled by medication.
Prinzmetal - occurs at rest and exhibits a circadian pattern - most episodes in the early hours of the morning.
Causes of angina
Atherosclerosis
Aortic stenosis
Hypertrophic
Obstructive cardiomyopathy
Hypertensive heart disease
Arrhythmias
Anaemia
Investigations for angina
12 lead ECG - LBBB, ST or T wave abnormalities (not NICE recommended)
FBC - rule out anaemia U+Es for renal function Fasting blood glucose LFTs Check TFTs Troponin
Echo
Exercise tolerance test
Estimate likelihood of coronary artery disease
- 90%+ treat as angina
- 61-90% - invasive coronary angiography
- 30-60% - non invasive functional testing for myocardial ischaemia
- 10-29% - CT calcium testing