Giant (Shark-Fin) R Waves — Acute Anterior STEMI (SSmith — 7-15-2015)

Giant (Shark Fin) R Waves — a sign of large acute Anterior STEMI



Great post illustrating how these amazingly tall "R waves" actually reflect huge ST elevation from acute STEMI!

An interesting facet of this series of tracings are the rhythms:

• TOP — Probably a LPH escape rhythm (RBBB/LAHB morphology; no P in lead II) — together with the markedly tall anterior R waves (really ST elev). A look at the limb leads and V6 is diagnostic for acute STEMI.
• MIDDLE — Runs of AIVR at 120/minute, but without ST elevation. Even though a ventricular rhythm, you'd expect some residual ST elevation — so the combination of AIVR plus no ST elevation suggests spontaneous reperfusion!
• There IS a P wave preceding beat #3 (probable sinus conduction). The first 2 beats in V1,2,3 look to be Fusion!
• BOTTOM — Highly unusual neg P preceding the QRS in the inferior leads. This is not WPW. Instead, I think it is a coronary sinus rhythm (with a short PR) — with QRS morphology kind of looking like the Fusion beats in the middle tracing.

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