Stable ischaemic heart disease and angina Flashcards
Definition
A discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
Pathophysiology
Mismatch between supply of oxygen and metabolites to myocardium and myocardial demand
Commonest cause of reduced blood flow through coronary arteries
Obstructive coronary atheroma
2 key characteristics of stable angina
Typical distribution of pain (centre of chest, left neck and jaw)
Precipitated by excess myocardial oxygen demand eg on exertion
What stage of atherosclerosis causes stable angina
Obstructive plaque
Characteristics of stable angina pain
Site - retrosternal
Character - often tight band/pressure/heaviness
Radiation - neck, jaw, down arms
Aggravating - with exertion, emotional stress and relieving factors - rapid improvement with GTN or physical rest
Describe the classification system for stable angina
Canadian classification of angina severity
I - symptoms on significant exertion
II - symptoms after 2 blocks or more than 1 flight of stairs
III - symptoms on 1 flight of stairs
IV - symptoms on any activity
Non-modifiable risk factors
age gender creed family history genetics
Modifiable risk factors
smoking lifestyle - exercise and diet diabetes mellitus hypertension hyperlipidaemia
Signs
tar staining
obesity
Xanthalasma and corneal arcus
hypertension
abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses
diabetic retinopathy, hypertensive retinopathy on fundoscopy
Signs of exacerbating or associated conditions
pallor of anaemia
tachycardia, tremo, hyper-reflexia of hyperthyroidism
ejection systolic murmur of mitral regurgitation
signs of heart failure such as basal crackles, elevated JVP, peripheral oedema
Investigations
Bloods CXR ECG Exercise tolerance test Myocardial perfusion imaging CT coronary angiography Invasive angiography Cardiac catherterisation
Three steps in treatment strategies
Address general measures
Medical treatment
Revascularisation
What comes under general measures in terms of treatment of angina
Address risk factors: BP, diabetes mellitus, cholesterol, lifestyle
What medical treatment influences the disease progression of stable angina
Statins - reduces LDL cholesterol deposition and reduces plaque rupture risk
ACE inhibitors - lowers BP so stabalises endothelium
Aspirin - Protects endothelium and reduces platelet aggregation
What medical treatment relieves symptoms
Beta blockers - reduces myocardial work Calcium channel blockers Ik channel blockers Nitrates - vasodilation, GTN spray K channel blockers
What two methods are options if medical treatment isn’t enough
Percutaneous coronary intervention (PCI)
Coronary artery bypass surgery (CABG)
What three things do drugs reduce in order to reduce cardiac workload
heart rate
myocardial contractility
afterload
What three types of drugs reduce the heart rate
Beta-adrenoceptor antagonists
Ivabradine
Calcium channel blockers
What two types of drugs are vasodilators
Calcium channel blockers
Nitrates (oral and sublingual)
What is the purpose of drug treatment (5 things)
Relieve symptoms Halt disease process Regression of the disease process Prevent myocardial infarction Prevent death
Which layer in the artery wall do most changes occur in atherosclerosis
tunica intima
Name 2 examples of beta blockers
Bisoprolol
Atenolol
How do beta blockers work
They block beta 1 and beta 2 receptors, blocking the response to adrenaline and noradrenaline ie the sympathetic system
