April 2007

Document Type


Degree Name



Oregon Health & Science University


Reducing the risk of delayed treatment to patients in the emergency department is a constant challenge. Recognizing atypical presentations of myocardial infarctions is a clinical challenge in the emergency department. Without the presence of chest pain, the staff is not cued to suspect a myocardial infarction, consequently delaying the onset of diagnostic interventions. To increase the care efficiency for patients with atypical symptoms of myocardial infarction, this study aimed to establish a pattern of presentation signs and symptoms, sample characteristics, risk factors and previous medical events to determine whether or not these patients have had a myocardial infarction. The present study demonstrated that 38.6% (CI of 35-42%) of patients diagnosed with a myocardial infarction presented to the emergency department with atypical signs and symptoms that would be considered "unrecognized". Previous studies have found between 24-40% subjects had "unrecognized" myocardial infarctions. The sample consisted of 316 subjects (171-54% with myocardial infarction) taken from the census of two hospital emergency departments, one urban setting and one community setting. The inclusion criteria were subjects who presented to the emergency department with dizziness or shortness of breath or were diagnosed with a myocardial infarction. The study was a retrospective descriptive chart review between April 2004 and August 2006. The variable that showed strongest evidence to suspect an atypical presentation of myocardial infarction was pain in other areas of the body, not in the chest (p = 0.0001). Other variables which would provide prompts to suspect a myocardial infarction were dizziness (p = 0.0001 ), previous stroke (p = 0.006), being senior [> 65 years] (p = 0.0 19), and being white (p = 0.016). Presenting to the emergency department with pain in other areas (p = 0.001) was associated with delays in diagnosing a myocardial infarction and achieving a timely percutaneous coronary intervention. Factors which may limit generalizability were a small sample size, comparative to the previous longitudinal research, and sampling from two hospitals within the same region. A growing national focus calls for development of strategies to standardize care. These data would provide the basis for a practice guideline for the emergency department staff to increase their ability to detect and expedite treatment for patients with atypical symptoms of myocardial infarction. This study utilized variable selections which were similar to other studies, however, the dependent variables and inclusion criteria varied between the studies. Presentation of pain in other areas was not a study variable in previous research. Most previous research utilized myocardial infarction patients and studied chest pain or not. The present study expanded the science by focusing on predicting myocardial infarction in patients who present to the emergency department with dizziness and shortness of breath. The clinical significance rests in the identification of this high-risk patient group of atypical presentation of myocardial infarction. The findings of this study will provide vital information targeting a large population of people at risk for myocardial infarction.




School of Nursing



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