2. IHD - Angina Flashcards
Define angina.
Angina is a type of IHD. It is a symptom of O2 supply/demand mismatch to the heart experienced on exertion.
What is angina pectoris?
Chest pain arising from the heart as a result of myocardial ischaemia
Name 3 types of angina
Classic/stable
Unstable/crescendo
Prinzmetal’s
What is Prinzmetal’s (variant) angina?
Angina that occurs without provocation, usually at rest - due to coronary artery spasm.
What are the differences between stable and unstable angina?
Stable angina is induced by effort + relieved by rest.
Unstable angina occurs at rest.
What is the most common cause of angina?
Narrowing of the coronary arteries due to atherosclerosis, leading to myocardial ischaemia
Give 5 possible causes of angina.
- Narrowed coronary artery = impairment of blood flow e.g. atherosclerosis.
- Increased distal resistance = LV hypertrophy.
- Reduced O2 carrying capacity e.g. anaemia.
- Coronary artery spasm.
- Thrombosis.
Give 5 modifiable risk factors for angina.
- Smoking.
- Diabetes.
- High cholesterol (LDL) / hyperlipidemia
- Obesity/sedentary lifestyle.
- Hypertension.
Give 3 non-modifiable risk factors for angina.
- Increasing age.
- Gender, male bias.
- Family history/genetics.
Give 5 risk factors for angina
Diabetes, smoking, hyperlipidaemia, hypertension, family history, lack of exercise
Briefly describe the pathophysiology of angina that results from atherosclerosis.
On exertion there is increased O2 demand. Coronary blood flow is obstructed by an atherosclerotic plaque -> myocardial ischaemia -> angina.
Briefly describe the pathophysiology of angina that results from anaemia.
On exertion there is increased O2 demand. In someone with anaemia there is reduced O2 transport -> myocardial ischaemia -> angina.
When does myocardial ischaemia occur?
Occurs when there is an imbalance between the heart’s oxygen demand and supply, usually from an increase in demand (eg exercise) accompanied by limitation of supply
What can cause a limitation in oxygen supply?
- Impairment of blood flow by proximal arterial stenosis
- Increased distal resistance E.G. left ventricular hypertrophy
- Reduced oxygen-carrying capacity of blood
E.G. Anaemia
How do blood vessels try and compensate for increased myocardial demand during exercise?
When myocardial demand increases e.g. during exercise, microvascular resistance drops and flow increases!
Why are blood vessels unable to compensate for increased myocardial demand in someone with CV disease?
In CV disease, epicardial resistance is high meaning microvascular resistance has to fall at rest to supply myocardial demand at rest. When this person exercises, the microvascular resistance can’t drop anymore and flow can’t increase to meet metabolic demand = angina!
How can angina be reversed?
Resting - reducing myocardial demand.
How would you describe the chest pain in angina?
Crushing central chest pain. Heavy and tight. The patient will often make a fist shape to describe the pain.
Give 5 symptoms of angina.
- Crushing central chest pain.
- The pain is relieved with rest or using a GTN spray.
- The pain is provoked by physical exertion.
- The pain might radiate to the arms, neck or jaw.
- Breathlessness.
Describe the presentation of angina
Central, crushing, retrosternal chest pain - comes on with exertion, relieved by rest.
May radiate to arms and neck
Give some clinical features, apart from pain, of angina
Dyspnoea, nausea, sweating, faintess
Give 3 symptoms you will NOT /rarely find in angina presentation.
- No fluid retention (unlike heart failure)
- Palpitation (not usually)
- Syncope or pre-syncope (very rare)