The first change ECG change during STEMI is “hyperacute T waves” which appear peaked and are related to localized hyperkalemia. These changes are rarely seen as they are transient and frequently occur prior to hospital arrival.
Choice A shows a "reverse bunny ear" pattern which meets morphology criteria for ventricular tachycardia. Choice B shows ST depression from the digoxin effect. Choice C shows inferior ST elevation which is a later ECG change on an inferior MI. Choice D shows biphasic T waves consistent with Wellen’s phenomenon.