Deadly ECG patterns — OMI equivalents and antidotes

ECG 1 — Wellens: Critical proximal LAD warning in the pain-free window; biphasic or deep inverted precordial T waves with preserved R waves. Manage as threatened OMI: antiplatelets, urgent angiography; never treadmill.^[1] Related OMI traps include de Winter (upslope STD + tall T) which also needs cath-lab activation.^[2]

ECG 2 — Na-channel block (TCA-type): Wide QRS, terminal R in aVR, often right-axis. Sodium bicarbonate 1–2 mmol/kg IV boluses; alkalinise; avoid class Ia/Ic antiarrhythmics; support BP; consider hyperventilation. ^[3]

ECG 3 — Hyperkalaemia sine wave: Calcium first for membrane stabilisation, then insulin–glucose ± salbutamol, urgent dialysis for removal. Do not treat primarily as VT with amiodarone. ^[4]

Unifying examiner point: Each deadly pattern maps to one committed action — cath lab, bicarbonate, or calcium — not passive observation.