According to a recent consensus document, Type 1 ST segment elevation, either spontaneously present or induced with the sodium channel-blocker challenge test, is considered diagnostic. Type 2 and 3 may lead to suspicion, but provocation testing is required for diagnosis. The ECGs in the right and left panels are from the same patient before (right panel, type 3) and after (left panel, type 1) administration of Ajmaline.