Stable Angina: Investigation, Diagnosis and Management Flashcards
What is angina?
A discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
What is angina pectoris?
Cardiac chest pain
Why does myocardial ischaemia occur?
Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them
What is the main cause of myocardial ischaemia?
Reduction in coronary blood flow to the myocardium
What can cause a reduction in coronary blood flow to the myocardium?
- Obstructive coronary atheroma (very common)
- Coronary artery spasm (uncommon)
- Coronary inflammation/arteritis (very rare)
What uncommon causes of myocardial ischaemia are there?
- Due to reduced O2 transport
- Due to pathologically increased myocardial O2 demand
What condition can cause reduced O2 transport?
Anaemia of any cause
What conditions can cause an increase in myocardial O2 demand?
- Left ventricular hypertrophy
- Thyrotoxicosis
What can cause left ventricular hypertrophy?
-Significant persistent hypertension -Significant aortic stenosis -Hypertrophic cardiomyopathy -
What is the most common cause of angina?
Coronary atheroma
How do the symptoms of angina occur?
On activity with the increased myocardial oxygen demand obstructed coronary blood flow leads to myocardial ischaemia and then the symptoms of angina
Give examples of situations in which myocardial oxygen demand increases.
When HR and BP rise:
- Exercise
- Anxiety/emotional stress
- After a large meal
- Cold weather
What is the typical distribution of pain and discomfort in angina?
Across left chest and down medial side of left arm
What must happen to coronary arteries before symptoms of angina are experienced?
Obstructive plaque that covers >70%
What will spontaneous plaque rupture and local thrombosis with degrees of occlusion result in?
Acute coronary syndromes
What symptoms will there be will a fatty streak in coronary arteries?
No symptoms
What symptoms will there be with a non-obstructive plaque in the coronary arteries?
No symptoms
Why is history essential to making a diagnosis of angina?
Essential to establish the characteristics of patients pain to differentiate from other causes of chest pain
How is angina pain described?
- Site
- Character
- Radiation
- Aggravating and relieving factors
- Site: retrosternal (watch for patients gestures)
- Character: often tight band/pressure/heaviness
- Radiation: neck and/or into jaw, down arms
- Aggravating factors: exertion and emotional stress
- Relieving factors: physical rest, rapid improvement with GTN
What features make it unlikely to be angina?
- Sharp/stabbing pain, pleuritic or pericardial
- Associated with body movements or respiration
- Very localised; pinpoint site
- Superficial with/or without tenderness
- No pattern to pain, particularly if often occurring at rest
- Begins some time after exercise
- Lasting for hours
In the differential diagnosis, what are CV causes?
- Aortic dissection
- Pericarditis
In the differential diagnosis, what are the respiratory causes?
- Pneumonia
- Pleurisy
- Peripheral pulmonary emboli
In the differential diagnosis what are the musculoskeletal causes?
- Cervical disease
- Costochondritis
- Muscle spasm or strain
In the differential diagnosis, what are the GI causes?
- Gastro-oesophageal reflux
- Oesophageal spasm
- Peptic ulceration
- Biliary colic
- Cholecystitis
- Pancreatitis
In the very rare occasion that myocardial ischaemia occurs with no chest pain, what other symptom may it present with on exertion?
- Breathlessness on exertion
- Excessive fatigue on exertion for activity undertaken
- Near syncope on exertion
Who is more likely to have symptoms other than chest pain n myocardial ischaemia?
-Elderly
-Those with diabetes mellitus
Probably dues to reduced pain sensation
What are the degrees of severity according to the Canadian classification of angina severity CCS?
I Ordinary physical activity does not cause angina, symptoms only on significant exertion
II Slight limitation of ordinary activity, symptoms on walking 2 blocks or >1 flight of stairs
III Marked limitation, symptoms o walking 1-2 blocks or 1 flight of stairs
IV Symptoms on any activity, getting washes/dressed causes symptoms
What non-modifiable risk factors are there?
- Age
- Gender
- Creed
- Family history
- Genetic factors
What modifiable risk factors are there?
- Smoking
- Lifestyle
- Diabetes mellitus
- Hypertension
- Hyperlipidaemia
What signs might be found on examination?
- Tar stains on fingers
- Obesity
- Xanthalasma and corneal arcus
- Hypertension
- Abdominal aortic aneurysm arterial brutis, absent or reduced peripheral pulses
- Diabetic retinopathy, hypersensitive retinopathy on fundoscopy
What are signs of exacerbating or associated conditions?
- Pallor of anaemia
- Tachycardia, tremor, hyper-flexia of hyperthyroidism
- Ejection systolic murmur, plateau pulse of aortic stenosis
- Pansystolic murmur of mitral regurgitation
- Signs of heart failure such as basal crackles, elevated JVP, peripheral oedema
What investigations should be carried out?
- Bloods
- CXR
- ECG
- Exercise tolerance test
- Myocardial perfusion imaging
- CT coronary angiography
- Invasive angiography
- Cardiac catheterisation/ coronary angiography
What bloods should be done?
- FBC
- Lipid profile
- Fasting glucose
- Electrolytes
- Liver and thyroid tests
Why is a CXR carried out?
Often helps show other causes of chest pain and can help show pulmonary oedema