Presenting symptoms in type 1 vs. type 2 myocardial infarction: A prospective study

Introduction: The classification of myocardial infarction (MI) into five types was introduced in 2007 as a component of the Universal definition. However, data outlining clinical symptoms in different MI types are limited. Purpose: To describe the presenting symptoms in patients with type 1 MI vs. type 2 MI. Methods: During January 2010-January 2011 unselected patients admitted to a single hospital with a catchment area of 300.000 residents were studied. All patients having cardiac troponin I measured on clinical indication were considered and had a supplementary history taken with focus on the debut symptoms at the time of MI. The diagnosis and classification of MI were according to the Universal definition. Thus, a rise/fall pattern of troponin values was required with at least one value above the 99th percentile of the upper reference limit. Also, clilinical evidence of myocardial ischemia had to be present. Results: During the inclusion period 360 patients with a type 1 MI were indentified, whereas 119 patients had a type 2 MI. As shown in the Table patients with type 1 MI more frequently had chest pain/discomfort than type 2 MI patients. However, patients with type 2 MI more often presented with dyspnea, palpitations or dizziness. The duration of symptoms in the two MI subtypes did not differ significantly. Conclusion: By use of a prospective design we found that the majority of patients with type 1 MI presents with symptoms of chest pain/discomfort, whereas the most frequent debut symptom in patients with type 2 MI appears to be dyspnea. (Table Presented ).