Difficult ECGs in STEMI: lessons learned from serial sampling of pre- and in-hospital ECGs

Area of Science:

• Cardiology
• Emergency Medicine
• Medical Diagnostics

Background:

• Prehospital electrocardiogram (ECG) interpretation is critical for timely ST elevation myocardial infarction (STEMI) diagnosis and treatment.
• Early recognition of ST-segment elevations (STE) in the prehospital setting reduces delays to reperfusion therapy.
• Certain ECG patterns, known as "STEMI equivalents," mimic STEMI and indicate significant ischemia but are often challenging to identify.

Purpose of the Study:

• To review critical and often overlooked ischemic ECG patterns encountered in prehospital care.
• To highlight diagnostic challenges posed by STEMI equivalents and other complex ECG presentations.
• To emphasize the importance of serial ECG acquisition in managing patients with potential myocardial infarction.

Main Methods:

• Review of critical ischemic ECG patterns, including STEMI equivalents.
• Discussion of diagnostic challenges in prehospital ECG interpretation.
• Emphasis on the utility of serial ECG acquisition.

Main Results:

• Identified several challenging ischemic ECG patterns that may be misinterpreted or missed by automated algorithms.
• Highlighted conditions like hyperacute T waves, de Winter ST-T complex, Wellens' syndrome, posterior STEMI, and STEMI in the context of LBBB, paced rhythms, or LVH.
• Underscored the potential for ephemeral or subtle ECG findings to indicate critical ischemia.

Conclusions:

• Accurate prehospital ECG interpretation, including recognition of STEMI equivalents, is essential for optimal patient outcomes.
• Awareness of subtle and atypical ischemic ECG patterns is crucial for avoiding misdiagnosis.
• Serial ECG monitoring can aid in the diagnosis of evolving myocardial infarction.