Final answer:
The threshold for ST elevation in STEMI is greater than 2mm for men under 40, 2.5mm for men 40 and over, and 1.5mm for women in leads V2-V3, and 1mm in all other leads, or a new LBBB.
Step-by-step explanation:
The threshold values for ST-segment elevation myocardial infarction (STEMI) include ST elevation greater than 2mm (0.2 mV) in leads V2 and V3 for men under 40 years old, 2.5mm for men aged 40 and over, and 1.5mm for women of any age. For all other leads, the threshold is 1mm (0.1 mV) or more in all other leads; or by new or presumed new left bundle branch block (LBBB). Identifying these elevations on an electrocardiogram (ECG) is critical for diagnosing a STEMI, which is a type of heart attack caused by a complete blockage of one of the heart's major arteries.