Initial electrocardiogram as determinant of hospital course in ST elevation myocardial infarction
Michael A Millard1, Vijaiganesh Nagarajan1, Luke C Kohan1
1Department of Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA.
Insights
About 15% of ST-elevation myocardial infarction (STEMI) patients initially have a nondiagnostic electrocardiogram (ECG). These patients present with more comorbidities and experience delayed treatment, highlighting a need for improved diagnostic strategies.
Area of Science:
- Cardiology
- Medical Diagnostics
- Emergency Medicine
Background:
- A subset of ST-elevation myocardial infarction (STEMI) patients initially present with nondiagnostic electrocardiograms (ECGs).
- Definitive STEMI diagnosis in these patients is often established through subsequent ECGs.
- Understanding differences between patients with initial diagnostic vs. nondiagnostic ECGs is crucial for optimizing care.
Purpose of the Study:
- To compare the characteristics of STEMI patients with nondiagnostic initial ECGs versus those with diagnostic initial ECGs.
- To identify factors associated with delayed diagnosis and intervention in STEMI patients.
Main Methods:
- Retrospective analysis of 334 STEMI patients undergoing primary percutaneous coronary intervention.
- Data collected included demographics, ECG findings, medications, angiographic results, and in-hospital outcomes.
- Comparison of patients diagnosed on initial ECG (85%) versus subsequent ECG (15%).
Main Results:
- Patients with nondiagnostic initial ECGs had higher rates of comorbidities (e.g., heart failure, CAD, diabetes, hyperlipidemia).
- These patients also showed increased chronic medication use and longer door-to-balloon and ECG-to-balloon times.
- Higher rates of a patent infarct-related artery were observed in the nondiagnostic group on baseline angiography.
Conclusions:
- Approximately 15% of STEMI patients have an initial nondiagnostic ECG.
- Nondiagnostic ECG presentations in STEMI are associated with increased comorbidities and delayed interventions.
- These findings underscore the importance of recognizing subtle ECG changes and potential delays in STEMI management.
Background:
A proportion of patients with ST elevation myocardial infarction (STEMI) have an initial electrocardiogram (ECG) that is nondiagnostic and are definitively diagnosed on a subsequent ECG. Our aim was to assess whether patients with a nondiagnostic initial ECG are different than those with a diagnostic initial ECG.
Methods:
We collected demographic, ECG, medication, angiographic, and in-hospital clinical outcome data in consecutive patients undergoing primary percutaneous coronary intervention for STEMI at our institution from June 2009 to June 2013.
Results:
A total of 334 patients were included, 285 (85%) diagnosed on the initial ECG and 49 (15%) on a subsequent ECG. Patients with a nondiagnostic initial ECG had more comorbidities including prior congestive heart failure (14% vs. 3%, p < .001), coronary artery disease (47% vs. 24%, p = .001), diabetes (37% vs. 16%, p = .001), and hyperlipidemia (55% vs. 40%, p = .048); higher rates of chronic medication use including aspirin (47% vs. 27%, p = .005), beta-blocker (47% vs. 22%, p < .001), and statins (53% vs. 28%, p = .001); longer door-to-balloon times (106 min vs. 45 min, p < .001); lower peak troponin levels (25 ng/ml vs. 50 ng/ml, p = .004), longer diagnostic ECG to balloon times (84 min vs. 75 min, p = .006); and higher rates of a patent infarct-related artery on baseline angiography (41% vs. 24%, p = .018) which remained significant in a multivariable logistic regression model.
Conclusions:
Approximately one in seven STEMI patients had an initial ECG that was nondiagnostic for STEMI. These patients had more comorbidities, higher rates of medication use, and received delayed intervention (even after the diagnosis was definitive).
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