Unstable Angina


Chest pain. Central, heavy chest pin radiating to the left arm and jaw Typically episodes of angina occurring on minimal provocation or at rest with poor response to GTN.
Dyspnoea and palpitations also common. Nausea and sweating.
Generally few symptoms between episodes of pain.

Symptoms overlap with other forms of ACS.


Features of pain - SOCRATES - sight, onset, character, radiation, associated features (autonomic features), time course, exacerbating/relieving factors (breathing, position, exertion, eating) and severity (0-10)
Generally pain is more frequent and severe than the patients 'usual' angina pain.
Recent trauma?
Does the patient have a GTN spray and has it helped their symptoms? - Poor response to GTN
Does the patient have any risk factors for developing vascular disease - Hypertension, hypercholesterolaemia, obesity, diabetes, previous acute coronary event/stroke, smoker, lifestyle/occupation, family history of ischaemic heart disease?
PMHx - consider other causes for the presenting symptoms, such as gastric, respiratory problems, MSK
Medications - cardiac or respiratory medications, antacids, anticoagulants

Vital signs / observations

  • Tachycardia/Bradycardia
  • Tachypnoeic


Cool and sweaty 'clammy', Palor. Tachycardia
Normal after episode of pain

Bedside tests

ECG - ST depression, inverted or flat T waves; subsequent evolution of changes + T wave inversion. Non-specific changes. ECG may be normal. Signs of previous MI.

Laboratory investigations

FBC, U&E, LFT, lipids, glucose, lactate
Cardiac Markers - various cardiac markers so check locally which you should send at what time-points after the onset of chest pain. Troponin I or T will show an increase 6 hour post-pain and remain raised for up to 14 days. Typically blood test taken on presentation and 12h after worst pain.
cardiac markers not elevated in unstable angina
Diagnosis is based upon history in the presence of ECG changes, but without subsequent elevation of cardiac markers
Consider ABG if patient acutely unwell

Radiological investigations

CXR - cardiomegaly, signs of LV failure (pulmonary oedema)
Urgent echo/CT if suspect other pathologies such as PE, Aortic dissection etc


Immediate management

Continually monitor pulse oximeter, BP and ECG

  • Morphine - eg IV Diamorphine 2.5-5mg + Antiemetic
  • Oxygen - only if SpO2 shows evidence of hypoxaemia
  • Nitratrates - GTN 400micrograms SL, 2 puffs SL every 5 minutes until pain free
  • Aspirin 300mg PO STAT


  • Clopidogrel 300mg PO
  • Anticoagulate with LMWH (Fondaparinux)
  • Beta Blockers Bisoprolol 10mg STAT, Metoprolol 50-100mg/8 hours but beware in patients with COPD, hypotension and LVF
  • IV Nitrate if pain continues

Risk Stratification

High Risk Patients Low Risk Patients
Clinical Features Persistent or recurrent ischaemia, ST depression, diabetes, raised troponin No further pain, flat or inverted T waves or normal ECG and negative troponin
Management CCU bed, consider for Glycoprotein IIb/IIIa inhibitors (e.g. Tirofiban) and urgent catheterisation Ensure pain free and arrange further tests such as exercise ECG, angiogram. Discharge home

Prior to discharge

Wean of GTN infusion when established on oral medication
Stop heparin when pain free for 24 hours, but give at least 3-5 days of therapy

Aim to reduce modifiable risk factors such as smoking, obesity, control of diabetes, blood pressure and cholesterol.


Smoking cessation and referral to cardiac rehabilitation


  • ACE inhibitor - eg ramipril. Start on low dose for example Ramipril 2.5mg daily, then increase to either 5mg then maximally 10mg
  • Statin, eg atorvastatin 10-80mg PO ON
  • Beta blocker, eg bisoprolol 5mg PO OD (this can be uptitrated as BP allows)
  • Aspirin - 75mg OD for life
  • Clopidogrel - 75mg OD for 12 months for patients who have had an NSTEMI regardless of treatment

Symptomatic treatment with nitrates (GTN) and possible addition of calcium channel blockers etc

Wean of GTN infusion when established on oral medication
Stop heparin when pain free for 24 hours, but give at least 3-5 days of therapy

Follow up

Review in out-patient clinic and through cardiac rehabilitation



  • Dysrhythmias
  • Cardiac Arrest
  • Pericarditis
  • Systemic Embolism
  • Valvular Pathology



Cardiac failure

  • Late malignant ventricular arrhythmias
  • Left Ventricular Aneurysm


Factors increasing mortality include:

  • History of unstable angina
  • ST depression or widespread T-wave inversion
  • Raised troponin
  • Age >70 years
  • General comorbidity
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