Clinical History: What Does the Evidence Show?

Radiation of pain to the arms or shoulders and association with exertion, diaphoresis, nausea or vomiting are useful for ruling in the diagnosis of AMI. Conversely, a history of pain that is sharp, positional or pleuritic decreases the probability of AMI.

What about burning pain?

Although traditionally it has been considered that pain described as burning or like indigestion suggests a gastro-oesophageal origin, data from emergency department patients with low risk chest pain suggests that this description actually increases the probability of AMI.

Emergency Physicians should therefore be very cautious about diagnosing low risk chest pain as gastro-oesophageal without first ruling out for cardiac disease.

How useful is clinical examination?

The only useful finding that is seen with any frequency is reproduction of pain by chest wall palpation, which reduces the probability of AMI but does not, on its own, rule out AMI.

It is also worth noting that it is reproduction of the pain by palpation that is useful, not simply eliciting tenderness by vigorous prodding.

The presence of hypotension, a third heart sound and pulmonary crepitations have been shown to increase the likelihood of AMI, but would not typically be found in patients with low risk chest pain.

How useful is the ECG?

ST segment deviation and deep T wave inversion indicate acute coronary syndrome with a substantial risk of adverse outcome. These changes must be identified and the patient admitted.

Other changes on the initial ECG are less specific. Minor T wave inversions (<3mm), flat or biphasic T waves may suggest myocardial ischaemia, but may also be positional or due to hyperventilation, hypertension, ventricular strain or previous cardiac disease.