The Diagnosis: "Shark Fin" Sign
The ECG pattern shown on the right is commonly referred to in cardiology as the "shark fin" sign.
It is associated with an acute, large-territory ST-elevation myocardial infarction (STEMI)—specifically, one involving the Left Anterior Descending (LAD) coronary artery. The pattern is characterized by the fusion of the QRS complex, ST segment, and T wave into a single, monophasic, triangular waveform that resembles the dorsal fin of a shark protruding from the water.