CHEST PAINGeneral Medical Emergencies 454 The pain may radiate to the neck, jaw, one or both arms, the back and
occasionally the epigastrium, or may present at these sites alone.
(i) Atypical symptoms occur more frequently in people with
diabetes, the elderly and in females.
5 The patient may be clammy, sweaty, breathless and pale or the patient may
appear deceptively well.
6 Alternatively, the patient may present with a complication such as a cardiac
arrhythmia (fast or slow), heart failure, severe hypotension with cardiogenic
shock, ventricular septal rupture or papillary muscle rupture, systemic
embolism or pericarditis.
7 Establish venous access with an i.v. cannula and attach a cardiac monitor and
pulse oximeter to the patient.
8 Send blood for full blood count (FBC), coagulation profile, electrolyte and
liver function tests (ELFTs), cardiac biomarker assay such as cardiac
troponin I (cTnI) or troponin T (cTnT) and lipid profile.
(i) Do not delay definitive management while awaiting a result.
(ii) Cardiac biomarkers do not rise for 4–6 h after symptom onset, so
can be normal early on.
(iii) Higher elevated troponin levels identify an increase in adverse
outcome risk.
9 Electrocardiogram (ECG). Perform this within 10 min of patient arrival, and
arrange for immediate review by a senior emergency department (ED)
doctor.
(i) Look for ST elevation in two or more contiguous leads.
(ii) The greater the number of leads affected and the higher the ST
segments, the higher the mortality.
(iii) Inferior myocardial infarction causes changes in leads II, III and
aVF.
(iv) Anterior myocardial infarction causes changes in I, aVL and
V1–V3 (anteroseptal) or V4–V6 (anterolateral).
(v) True posterior myocardial infarction causes mirror-image
changes of tall R waves and ST depression in leads V1–V4.
(vi) Repeat the ECG after 5–10 min in symptomatic patients with an
initial non-diagnostic ECG.
10 Perform a CXR to look for pulmonary oedema, cardiomegaly and atelectasis.
Request a portable X-ray in the ED, provided this does not delay definitive
management.
MANAGEMENT1 Give high-dose 40–60% oxygen unless there is a prior history of obstructive
airways disease, in which case give 28% oxygen. Aim for an oxygen satura-
tion (SaO 2 ) over 94%.