In a patient with STEMI, what is the minimum ST-segment elevation size recognized in leads V2 and V3?

The minimum ST-segment elevation size recognized in leads V2 and V3 for a diagnosis of ST-Elevation Myocardial Infarction (STEMI) is 0.15 mV (or 1.5 mm). This elevation is significant because it indicates that there is a substantial injury to the heart muscle, which is critical for prompt identification and treatment.

Elevated ST segments reflect the electrical changes occurring in the myocardium due to ischemia. In STEMI, these changes arise from a complete occlusion of a coronary artery, causing a significant and prolonged reduction in blood flow to a region of the heart. The 0.15 mV threshold specifically in leads V2 and V3 is essential for differentiating a STEMI from other types of myocardial damage or less severe forms of ischemia.

Recognizing this elevation promptly is crucial for initiating appropriate interventions, such as reperfusion therapy, which can improve outcomes for patients experiencing a STEMI.