21. Stable Angina: diagnosis, investigation and management (stable ischaemic heart disease) Flashcards
Define angina.
- Simply means pain, but has been adopted to mean cardiac chest pain (angina pectoris).
- a discomfort in chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
Define ischaemia.
inadequate blood supply to an organ or tissue, especially the heart muscle
What is the main cause of a stable angina?
- Pathophysiolgoy of myocardial ischaemia and resultant anginal symptoms
- Mismatch between supply of O2 and metabolites to myocardium and the myocardial demand for them
What is the number 1 cause for stable angina?
due to reduction in coronary blood flow to the myocardium
What are 3 causes of reduction in coronary blood flow to myocardium?
- obstructive coronary atheroma (very common)
- coronary artery spasm (uncommon)
- coronary inflammation/ arteritis (very rare)
What are uncommon causes for stable angina? (2)
- due to reduced O2 transport in anaemia of any cause
- due to pathologically increased myocardial O2 demand and increased metabolic rate e.g. left ventricular hypertrophy or thyrotoxicosis
What is thyrotoxicosis?
- main cause is hyperthyroidism
- overactivity of the thyroid gland producing excess levels of thyroid hormones
In which conditions is left ventricular hypertrophy (LVH) seen which causes ischaemia? (3)
- persistent hypertension
- significant aortic stenosis
- hypertrophic cardiomyopathy
What is the most common cause of angina?
coronary atheroma
How does increased myocardial oxygen demand lead to symptoms of angina?
On activity, increased O2 demand is needed due to obstructed coronary flow which leads to myocardial ischaemia and therefore symptoms of angina.
In what situations does myocardial oxygen demand increase? (5)
Where heart rate and BP rise. eg. :
- exercise
- anxiety/emotional stress
- after a large meal
- cold weather
- on exertion
What is meant by STABLE angina?
Chest pain which occurs on activity or emotional stress(due to poor blood flow in coronary vessels when there is precipitated excess myocardial oxygen demand)
What is a common description of angina by patients? (3)
- heaviness
- squeezing sensation (tightness)
- hand over central chest sometimes pain going over left arm
To which locations can angina pain spread to? (5)
- back
- jaw
- arm (most often left)
- neck
- shoulder
When is plaque considered “obstructive”?
when plaque takes up >70% of lumen
At what stage of plaque formation can symptoms usually begin to appear?
begin to appear when lumen narrowing is >70% obstructed
Describe stages of plaque formation.
1, normal
- fatty streak
- non-obstructive plaque
- obstructive plaque (>70% of lumen)
- spontaneous plaque rupture
When does acute coronary syndrome become apparent? (what are features of the plaque)
spontaneous plaque rupture and local thrombosis with degrees of occlusion
During which breathing stage do atherosclerosis symptoms become apparent?
on exertion
During which breathing stage does acute coronary syndrome become apparent?
symptoms not exclusive to exertion only but also at rest (symptoms can be noticed at any stage of breathing)
What is the main component of history taking that will help distinguish angina from other differential diagnosis options?
essential to establish the characteristics of patient’s PAIN
What features of pain should be found out in patient’s history who presents with angina-like symptoms? (4)
- SITE of pain; watch for patient’s gestures, retrosternal (behind sternum)
- CHARACTER of pain; often tight band, pressure, heaviness
- RADIATION sites; neck and/or into jaw, down arms
- AGGRAVATING; with exertion, emotional stress and relieving factors (e.g. rapid improvement with GTN or physical rest)
What is myocardial ischaemia almost always characterised as?
characterised as being relieved with GTN within 2 or 3 minutes
What features of pain make angina not likely? (7)
- sharp/stabbing/ sudden pain; pleuritic or pericardial
- associated with body movements or respiration
- very localised, pinpoint site
- superficial with/or without tenderness
- no pattern of pain, particularly if often occuring at rest
- begins some time AFTER exercise
- lasting for hours
What 4 body systems are differential diagnoses for chest pain? (with characteristics different to angina)
- cardiovascular causes
- respiratory causes
- musculoskeletal causes
- GI causes
What are the other cardiovascular causes for chest pain which are part of the differential diagnosis but have different characteristics to angina?(2)
- aortic dissection; tear in part of aorta (intra-scapular tearing)
- pericarditis
What are the other respiratory causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (3)
- pneumonia
- pleurisy
- peripheral pulmonary emboli (pleuritic)
What are the other musculoskeletal causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (3)
- cervical disease
- costochondritis
- muscle spasm or strain
What are the other GI causes for chest pain which are part of the differential diagnosis but have different characteristics to angina? (6)
- gastro-oesophageal reflux
- oesophageal spasm
- peptic ulceration
- biliary colic (gallstone blocking bile duct)
- cholecystitis (inflammation of gallbladder)
- pancreatitis
What treatment is given to confirm angina?
relieved symptoms with GTN or rest
What other symptoms on exertion may indicate angina (myocardial ischaemia) that are NOT chest pain?(3)
- breathlessness on exertion
- excessive fatigue on exertion for activity undertaken
- near syncope on exertion (fainting)
What is another name for angina?
myocardial ischaemia
What group of patients present with angina symptoms on EXERTION that are not chest pain? Why?
- elderly
- patients with diabetes mellitus
(probably due to reduced pain sensation)
What system is used to distinguish severity of angina?
Canadian classification of angina severity (CCS)
What is stage 1 of CCS of angina classification?
Ordinary physical activity does not cause angina, symptoms only on significant exertion (least severe)
What is stage 2 of CCS of angina classification?
Slight limitation of ordinary activity, symptoms on walking 2 blocks or>1 flight of stairs
What is stage 3 of CCS angina classification?
marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs
What is stage 4 of CCS angina classification?
Symptoms on any activity, getting washed/ dressed causes symptoms (most severe)
What are non-modifiable risk factors for coronary heart disease? (6)
- age
- gender
- creed (religion)
- ethnicity
- family history
- genetic factors
What are modifiable risk factors for coronary heart disease? (6)
- smoking
- lifestyle exercise and diet
- diabetes mellitus (glycaemic control reduces CV risk)
- hypertension ( BP control reduces CV risk)
- hyperlipidaemia (lowering reduces CV risk)
- people living at higher latitudes
What are clinical signs seen on examination in patients with stable angina? (6)
- tar stains on fingers
- obesity (centripedal)
- xanthalasma and corneal arcus (hypercholesterolaemia)
- hypertension
- abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses
- diabetic retinopathy, hypertensive retinopathy on fundoscopy
What is a bruit?
- Turbulent sound of blood flow
- Usually caused by a narrowing of an artery
- sound usually heard over artery or vascular channel