A Dangerous Wave: Recognizing the Shark-Fin ECG Sign in STEMI
Avinash Radhakrishna1, Ailis Pollock1, John Cosgrave1
1Department of Cardiology, Saint James's Hospital, Dublin, Ireland.
Case Summary:
The shark-fin morphology on electrocardiogram (ECG) represents a malignant ST-segment elevation myocardial infarction pattern associated with profound transmural ischemia. A 49-year-old man with episodic chest pain had an initially nondiagnostic ECG. With recurrent symptoms and rising troponins, repeat ECG showed ventricular bigeminy and a giant triangular QRS-ST-T waveform in the anterolateral leads. Angiography revealed subtotal proximal left anterior descending artery occlusion, which was managed urgently with percutaneous coronary intervention.
Take-Home Messages:
The shark-fin morphology is a rare but malignant ST-segment elevation myocardial infarction pattern that may mimic wide-complex ECG abnormalities. Prompt recognition should trigger immediate reperfusion and vigilance for cardiogenic shock and ventricular fibrillation.
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