Flashcards in Stable Ischaemic Heart Disease and Angina Presentation and Investigation Deck (59)
What is angina?
Discomfort/pain in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
What is angina a result of?
Mismatch between supply of oxygen and metabolites to the myocardium and the myocardial demand for them
What is angina most commonly due to?
Reduction in coronary blood flow to the myocardium caused by;
obstructive coronary atheroma
coronary artery spasm
What might cause angina, other than reduction in coronary blood flow to the myocardium?
Reduced oxygen transport e.g. anaemia of any cause
Pathologically increased myocardial oxygen demand e.g. left ventricular hypertrophy or thyrotoxicosis
What is the most common cause of angina?
When does myocardial oxygen demand increase?
In situations where heart rate and blood pressure rise e.g. exercise, anxiety, emotional stress etc.
What is necessary in order for ischaemia to occur?
Lumen has to be reduced by more than 70%
What are the non-modifiable risk factors of stable angina?
What are the modifiable risk factors of stable angina?
Lifestyle e.g. diet and exercise
Good control of diabetes, hypertension and hyperlipidaemia reduce the risk
What are the typical characteristics of angina?
Described as tight band/pressure/heaviness
May radiate to neck, jaw or down arms
Aggravated by exertion and emotional stress
Relieved by GTN and physical rest
Give some characteristics of pain that make the diagnosis of angina less likely
Associated with normal body movements or respiration
No pattern to pain
Begins some time after exercise
Lasts for hours
What are some cardiovascular differential diagnoses of chest pain?
What are some respiratory differential diagnoses of chest pain?
Peripheral pulmonary emboli
What are some musculoskeletal differential diagnoses of chest pain?
Muscle spasm or strain
What are some gastrointestinal differential diagnoses of chest pain?
If myocardial ischaemia occurs without chest pain, what other symptoms might be present on exercise? Who is this more common in?
Excessive fatigue for the activity undertaken
Near syncope on exertion
More common in the elderly or those with diabetes mellitus
What is the Canadian Classification of Angina Severity (CCS) grading?
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 on walking only 1-2 blocks or 1 flight of stairs
IV – symptoms on any activity, getting washed/dressed causes symptoms
What signs might be seen on examination of a patient with angina?
Abdominal aortic aneurysm bruits
Absent or reduced peripheral pulses
Diabetic retinopathy or hypertensive retinopathy
What signs of exacerbating/associated conditions might be seen on examination of a patient with angina?
Pallor of anaemia
Tachycardia, tremor, hyper-reflexia or hyperthyroidism
Ejection systolic murmur, plateau pulse of aortic stenosis
Pansystolic murmur of mitral regurgitation
Signs of heart failure e.g. basal crackles, elevated JVP, peripheral oedema
What blood tests are relevant in the investigation of stable angina?
Liver function tests
Thyroid function tests
What investigations (other than blood tests) are relevant in the investigation of stable angina?
Exercise tolerance test
Myocardial perfusion imaging
Cardiac catheterisation/coronary angiography
In what percentage of cases of angina will the electrocardiogram be normal?
What might an electrocardiogram show evidence of?
Previous MI e.g. pathological Q waves
Left ventricular hypertrophy e.g. high voltages, lateral ST-segment depression
How is an exercise tolerance test useful?
Can often confirm the diagnosis of angina
When is an exercise tolerance test positive?
When patient has typical symptoms and ST-segment depression
What does an exercise tolerance test depend on?
Ability to walk for long enough to produce sufficient cardiovascular stress
What is the prognosis of a negative exercise tolerance test?
Doesn't exclude significant coronary atheroma but if negative at a high workload the overall prognosis is good
In what ways is myocardial perfusion imaging superior to exercise tolerance testing?
Detection of coronary artery disease
Localisation of ischaemia
Assessing size of area affected
What are the disadvantages of myocardial perfusion imaging?