Coronary syndromes Flashcards
How do plaques develop?
fatty streak - endothelial dysfunction, lipoprotein entry + modification, leukocyte recruitment, foam cell formation
plaque progression - smooth muscle cell migration, altered matrix synthesis and degradation
plaque disruption - disrupted plaque integrity, thrombus formation
CAD modifiable risk factors
smoking
hypertension
high cholesterol
diabetes
CAD non-modifiable risk factors
age
gender
family history
ethnicity
What calculator is used to assess cardiovascular disease risk?
QRISK2
What is atherosclerosis?
chronic disease characterised by inflammation and lipid deposition affecting the intima
affects large and medium sized muscular and elastic arteries
branch points and bifurcations are particularly at risk (due to more turbulent blood flow)
What 2 factors cause ischaemia in stable angina?
fixed vessel narrowing
abnormal vascular tone
What does the effect of a stenosis on blood flow depend on?
degree of narrowing of epicardial vessel
amount of compensatory vasodilation that the arterioles can achieve
What does abnormal vascular tone result in?
(endothelial dysfunction causes abnormal vascular tone)
results in:
- inappropriate vasoconstriction of coronary arteries
- loss of normal antithrombotic properties
What are 4 broad characteristics of angina?
location
character
precipitating and relieving factors
duration
Angina location
retrosternal
diffuse
may involve both sides of chest (L>R), arms (L>R), neck, lower jaw, upper abdomen
Angina character
pressure, tightness of heavy weight
sometimes burning
Angina precipitating and relieving factors
provoked by exertion (walking uphill)
more easily provoked after heavy meal/cold weather
rapid relief (2 mins) with GTN
Angina duration
attacks last a few minutes (not very brief or very prolonged)
Describe a stable angina artery
lumen narrowed by plaque
inappropriate vasoconstriction
Describe an unstable angina artery
plaque rupture
platelet aggregation
thrombus formation
unopposed vasoconstriction
Describe a variant angina artery
no overt plaques
intense vasospasm
Cardiac causes of recurrent chest pain
angina
pericarditis
GI causes of recurrent chest pain
reflux (GORD)
peptic ulcer
oesophageal spasm
biliary colic
MSK causes of recurrent chest pain
costochondral syndrome
cervical radiculitis
Diagnostic tests for coronary artery disease
ECG
Stress tests - exercise ECG, myocardial perfusion imaging, stress echocardiography, stress MRI
Imaging - Non-invasive = CT coronary angiogram, Invasive = coronary angiogram
Define myocardial ischaemia
reduced blood supply to the heart
Define myocardial infarction
necrosis of myocardial cells
What does transmural MI mean?
full thickness
What are acute coronary syndromes usually due to?
plaque rupture
What are the 2 types of plaques?
stable
vulnerable
Describe a stable plaque
thick fibrous cap, small lipid pool
Describe a vulnerable plaque
thin fibrous cap, large lipid pool
What does plaque rupture cause?
exposes thrombogenic extracellular matrix and lipid core to circulation
–> platelet aggregation and thrombus formation
What are the 2 types of ACS?
ST elevation (STEMI)
Non-ST elevation (NSTEMI)
How can an ECG appear in a STEMI? (and how does it change over time)
Acute = ST elevation
hours = ST elevation, reduced R wave, Q wave begins
days 1-2 = T wave inversion, Q wave deeper
days later = ST normalises, T wave inverted
weeks later = ST + T normal, Q wave persists
How can an ECG appear in an NSTEMI? (and how does it change over time)
Acute = T wave inversion or ST depression
weeks later = ST + T normal, no Q waves
Post MI complications
ACT RAPID
Arrhythmias
Congestive cardiac failure/cardiogenic shock
Thromboembolism
Rupture (ventricular free wall, septum, papillary muscle)
Aneurysm
Pericarditis
Ischaemia
Death/Dressler’s syndrome
main late complications = arrhythmias and heart failure
If there is partial occlusion of a coronary artery, what is this called?
NSTEMI
If there if complete occlusion of a coronary artery, what is this called?
STEMI
Symptomatic treatment for stable coronary artery disease
lifestyle
drugs - antianginals, nitrates
revascularisation (eg. PCI)
Prognostic benefit treatment for stable coronary artery disease
lifestyle (stop smoking)
drugs - statins, aspirin, beta blockers, ACE inhibitors
revascularisation eg. CABG
Define ischaemia
inadequate oxygen supply to myocardial tissue
What factors could affect supply of oxygen to myocardial tissue?
coronary stenosis
anaemia
lung problems
What factors could affect demand of oxygen supply to myocardial tissue?
tachycardia
preload (venous return)
afterload (BP)
muscle mass (eg. hypertrophy, infarcted)
muscle contractility
What investigations can be done to confirm angina?
exercise stress test (low sensitivity and specificity)
MIBI
CTCA (anatomical test)
stress MRI
dobutamine stress echo
coronary angiogram
CTCA (CT coronary angiogram) = first line for most patients
What is PCI?
percutaneous coronary intervention
Indications for PCI
stable angina:
- limiting symptoms despite 2 anti-anginals
ACS:
- NSTEMI = urgent
- STEMI = emergency treatment
Indications for CABG
‘surgical disease’:
- left main stem
- LM equivalent
- proximal 3 vessel disease
especially if:
- left ventricular dysfunction
- diabetes
- complex disease (high risk score - syntax score)
NSTEMI drugs
dual antiplatelet (aspirin, ticagrelor)
anticoagulant
beta blocker
statin
long term = consider ACE-i/ARB
What would the troponin be in unstable angina?
near normal
If chest pain radiates to back, what needs to be ruled out?
aortic dissection - tenni ball sign seen on CT
What can PE cause a rise in?
troponin (due to right heart strain)
What other events can cause ST elevation (other than STEMI)?
brain events (eg. subarachnoid haemorrhage)
Modifiable biomedical risk factors for coronary heart disease
diabetes
high blood cholesterol
hypertension
Lifestyle/behavioural risk factors for coronary heart disease
smoking
sedentary lifestyle
obesity
diet
alcohol
stress
Non-modifiable risk factors for coronary heart disease
family history
gender
ethnicity
age
What family history increases risk of coronary heart disease
1st degree female relative under 65
1st degree male relative under 55
risk increases 1.5x if one relative
risk increases 1.5-2x if more than one relative
familial hypercholesterolaemia
Secondary prevention of coronary heart disease
anti-platelets (aspirin, clopidogrel, ticagrelor)
beta-blockers
statin
ACE-i
lifestyle modification
psychosocial factors
cardiac rehabilitation
Lifestyle modifications to reduce blood pressure
weight loss
mediterranean diet
reduced salt intake
physical activity
moderate alcohol
HDLs function
(high density lipoproteins)
carry cholesterol away from arteries and back to liver, then excreted from the body
LDLs function
(low density lipoproteins)
build up in the walls of the arteries to form thick, hard deposits that narrow the arteries and make them less flexible
Triglycerides function
main storage form of LDL
What lifestyle modifications can improve lipid profile?
diet
aerobic exercise
resistance training
What is obesity associated with?
raised BP
raised LDL and triglycerides
low HDL
impaired glucose tolerance
increased insulin resistance
Diet modifications to reduce coronary heart disease risk
pile on fruit and vegetables
choose healthy fats
pick seeds, nuts and legumes
focus on fish and chicken over red meat
add herbs and spices rather than salt
What is cardiac rehabilitation?
comprehensive, long-term programs involving medical evaluation, prescribed exercise, cardiac risk factor modification, education and counselling
designed to limit physiologic and psychological effects of cardiac illness, reduce the risk for sudden death or re-infarction, control cardiac symptoms, reverse/stabilise atherosclerotic process and enhance vocational status of patients
6 core components of BACPR
health behaviour change and education
lifestyle risk factor management
psychosocial health
medical risk management
long-term strategies
audit and evaluation
What is the heart manual?
home based exercise program
trained facilitators
inclusion/exclusion criteria
principles of self-management:
- gain understanding and acceptance of condition
- pace themselves
- set short, medium and long-term goals
- promote realistic exercise and activity
- self monitor progress and condition
- maintain behaviour change
- deal with setbacks
What types of fat should you eat?
MUFA/PUFA (monounsaturated/polyunsaturated fatty acids)
reduce amounts of saturated fat eaten
