
The classic presenting symptom of ACS is chest pain, which is traditionally described as having a characteristic nature:
Likelihood ratios have been calculated that link features of the history with AMI [8-10].
Table of likelihood ratios
| Historical factor | Likelihood ratio | ||
| Ref 8 | Ref 9 | Ref 10 | |
| Increased likelihood of AMI: | |||
| Radiation to right arm/shoulder | 4.7 | 2.9 | 2.6 |
| Radiation to both arms/shoulders | 4.1 | 7.1 | 4.1 |
| Associated with exertion | 2.4 | ||
| Radiation to left arm | 2.3 | 2.3 | 1.5 |
| Associated with diaphoresis | 2.0 | 2.0 | 2.1 |
| Associated with nausea/vomiting | 1.9 | 1.9 | 1.9 |
| Worse than previous angina/similar to previous MI | 1.8 | 1.3 | |
| Described as a pressure | 1.3 | 1.4 | |
| Decreased likelihood of AMI: | |||
| Described as pleuritic | 0.2 | 0.2 | 0.2 |
| Described as positional | 0.3 | 0.3 | 0.3 |
| Described as sharp | 0.3 | 0.3 | 0.3 |
| Reproducible with palpation | 0.3 | 0.2 – 0.4* | 0.2 |
| Inframammary location | 0.8 | ||
| Not associated with exertion | 0.8 | ||
* In heterogenous studies, likelihood ratios are expressed as a range.
Learning Bite
No single factor in the history alone can confidently rule in or rule out AMI; characteristics of the pain with the highest likelihood for AMI are radiation of the pain to the right arm or shoulder, or to both arms or shoulders.