BACKGROUND: Acute myocardial infarction (AMI) will not develop in a large proportion of patients admitted to the coronary care unit because of suspected AMI. OBJECTIVE: To evaluate whether patients with confirmed AMI use different words to describe their pain than patients in whom AMI was not confirmed. DESIGN: A retrospective descriptive design. METHODS: The Pain-O-Meter, a verbal pain scale composed of 12 sensory and 10 emotional word descriptors, was used to assess pain. SETTING: Coronary care unit in Sahlgrenska Hospital in Goteborg, Sweden. SUBJECTS: A convenience sample of 889 consecutive patients admitted to the coronary care unit because of suspected AMI. RESULTS: SENSORY COMPONENT--patients with confirmed AMI differed from those without AMI in the use of the words "pricking" (12% vs 17%; p < 0.05) and "tearing" (11% vs 6%; p < 0.05). No difference was found in the remaining 10 words. Affective components--Patients with confirmed AMI differed from those without AMI in the use of "terrifying" (29% vs 18%; p < 0.001), "intolerable" (16% vs 10%; p < 0.01), and "worrying" (48% vs 59%; p < 0.01). Women used stronger word descriptors more frequently than men. CONCLUSION: The use of specific or more word descriptors to separate patients with AMI from those without AMI was not supported by the study data. Although patients with AMI more frequently used the sensory word tearing as well as the affective words terrifying and intolerable and less frequently used the sensory word pricking and the affective word worrying than patients without AMI, the differences do not suggest a clinical profile that can be used to differentiate these clinical entities.