The patient's interpretation of myocardial infarction symptoms and its role in the decision process to seek treatment: the MONICA/KORA Myocardial Infarction Registry

The patients' misinterpretation of symptoms of an evolving acute myocardial infarction (AMI) is a major cause for prolonged pre-hospital delays. The objective of this study was to identify factors associated with an attribution of the symptoms to the heart and to investigate the association between symptom misinterpretation and time until first medical contact (delay time). The study population comprised 1,684 men and 559 women, aged 25-74 years, hospitalized with a first-time AMI recruited from a population-based AMI Registry. A total of 50.3 % of the patients attributed their experienced symptoms to the heart. Logistic regression modeling revealed that symptoms like chest pain, pain in the left upper extremity, and fear of death facilitated a correct attribution to the heart, whereas symptoms like vomiting or pain in the right upper extremity made a correct labeling difficult. Female sex, low educational status, migration background, and current smoking were associated with a higher risk of misinterpretation of symptoms. A family history of AMI or a history of angina pectoris, hypertension, and hyperlipidemia were shown to facilitate a correct interpretation of symptoms. Variables associated with a misinterpretation of symptoms did not significantly differ between men and women. People with misinterpretation of symptoms had a 1.59-fold risk (95 % confidence interval 1.33-1.90) to have a delay time of at least 2 h, compared with persons who correctly attributed their symptoms. Symptom misinterpretation is common among patients with AMI, significantly related to symptoms, sociodemographic characteristics and individual risk factors, and associated with a prolonged delay time.