Investigations may identify the presence or effects of
coronary artery stenosis but, where this cannot be achieved,
a broader aim is to further refine risk stratification to identify
patients at low risk of an adverse outcome after discharge
from the hospital or ED. Exercise stress electrocardiography
has become largely obsolete as a means of diagnosing
reversible myocardial ischaemia, due to insufficient diagnostic
accuracy, but it retains a well established role in identifying
patients with chest pain who can safely be discharged
from the ED.17,18 Exercise stress electrocardiography may be
limited by patients’ inability to exercise at an adequate level,
non-specific electrocardiographic changes (particularly in
the setting of an abnormal resting ECG), and false positive
results, but it remains attractive by virtue of its low cost and
widespread availability.