From the Guidelines
Non-cardiac causes of ST elevation include pericarditis, early repolarization, Brugada syndrome, and secondary repolarization abnormalities such as right or left bundle branch block, paced rhythms, ventricular hypertrophy, and ventricular preexcitation. These conditions can mimic myocardial infarction on an electrocardiogram (ECG) and require careful consideration to avoid unnecessary cardiac interventions 1.
Key Conditions
- Pericarditis or myopericarditis, often with diffuse changes on the ECG, including ST-segment elevation (or, more frequently, PR depression) in multiple leads, representing inflammation rather than true ischemia 1.
- Early repolarization pattern, described as widespread and consistent ST-segment elevation at the J point, with characteristic QRS slurring or notching (a positive deflection on terminal QRS complex); preservation of the initial concave upsloping; and prominent T waves in at least 2 contiguous leads 1.
- Brugada syndrome, manifested by right bundle branch block and ST-segment elevation in leads V1 through V3 among patients who, despite absence of chest pain, are at high risk for syncope or death resulting from ventricular tachycardia or ventricular fibrillation (VF) 1.
Secondary Repolarization Abnormalities
- Right or left bundle branch block
- Paced rhythms
- Ventricular hypertrophy
- Ventricular preexcitation Recognizing these non-cardiac causes is crucial to avoid unnecessary cardiac interventions, as treatment should target the underlying condition rather than presumed coronary occlusion. Clinical context, patient history, and additional diagnostic tests can help differentiate these conditions from acute coronary syndrome 1.
From the Research
Non-Cardiac Causes of ST Elevation
The provided studies primarily focus on ST-elevation myocardial infarction (STEMI) and non-ST-elevation acute coronary syndromes (NSTE-ACS), with limited direct information on non-cardiac causes of ST elevation. However, we can infer some relevant points:
- Non-ischemic ST elevation can be caused by conditions other than acute ischemia, as discussed in 2.
- These non-ischemic causes can sometimes be confused with STEMI on an electrocardiogram (ECG), highlighting the importance of interpreting the ECG in its clinical context. Some key points about non-ischemic ST elevation include:
- It may be caused by various non-cardiac conditions, although specific causes are not detailed in the provided studies.
- Distinguishing between ischemic and non-ischemic ST elevation is crucial for appropriate treatment, as early perfusion in non-ST elevation myocardial infarctions has not been shown to be beneficial 2.
- The importance of rapid and accurate interpretation of the ECG cannot be overstated, as it lies at the heart of delivering the best care for patients with ST elevation 2. Key considerations for non-cardiac causes of ST elevation, based on the available information, include:
- The clinical context in which the ST elevation occurs is critical for determining its cause.
- Non-ischemic ST elevation patterns and methods for distinguishing them from ischemic causes are important for accurate diagnosis and treatment 2.