Case 2.4 – Coronary Artery Disease (Unstable Angina)
Category: Cardiovascular | Discipline: Medicine | Setting: Emergency Department
Case
Martin Angus, aged 54 years, presents with worsening angina. Previously he experienced one episode a month that was rapidly relieved with nitrates. However, he has experienced three episodes in the past week. The most recent episode of chest pain started 1 hour ago and came on at rest. Although relieved by nitrates, he still feels unwell.
Questions
1. What elements of the history cause most concern?
Changes in the frequency of angina
Angina occurring at rest
Ongoing sensation of feeling unwell despite taking nitrates, which previously have relieved pain well
2. What further history and examination is warranted?
Further history must try and ascertain whether this could be a presentation of a myocardial infarction. This includes:
Type and nature of the pain, radiation of the pain
Whether there was a change in the pain with the application of the nitrate
Associated physical symptoms such as breathlessness, light-headedness, nausea, vomiting, sweating
A sense of fear or impending doom
Physical examination:
Signs of sympathetic activation: pallor, sweating and tachycardia
Signs of vagal activation: bradycardia and vomiting
Pallor and cool peripheries
Pulse (character and rate)
Blood pressure (hypotension)
JVP
Character of the apex beat
Auscultate for heart sounds (quiet S1, S3)
Auscultate the chest for crackles
3. What investigations would you order?
Blood tests (FBC, EUC, LFT, coagulation screen, ESR, C-reactive protein, serial levels of troponins or if this was not available, CK, CKMB)
Serial ECG
Chest x-ray
Fasting blood glucose, fasting lipid profiles
Echocardiography
4. What is the economic impact of cardiovascular disease in Australia?
Despite improvements in survival, cardiovascular disease remains one of the most common causes of mortality and morbidity in Australia.
National Heart Foundation figures (2004):
CVS disease accounts for 36% of all deaths in Australia
Responsible for the death of one Australian every ten minutes
More than 3.5 million Australians are currently diagnosed with heart disease
Prevents 1.4 million people from living a full life because of disability caused by the disease
Australian Bureau of Statistics data (2000-01):
Cardiovascular disease is the most expensive health condition
Costs 11% or 5.4 billion dollars of the total allocated health system expenditure
Predicted to increase as the incidence increases with age and the number of older Australians increases
5. What interventions have been demonstrated to improve mortality in asymptomatic individuals with risk factors?
Moderate to high levels of physical activity
Cessation of smoking and modification of risk factors (e.g. diabetes, lipid profile, hypertension)
6. What interventions have been demonstrated to improve mortality in symptomatic individuals?
Pharmacological interventions:
Prescription of statins (whatever the cholesterol level)