NonST

NonST is a shorthand term used in technical writing to indicate something that is not ST, or not related to the ST segment in electrocardiography. It is not a formal medical diagnosis on its own. In many contexts, particularly cardiology, non-ST denotes the absence of ST-segment elevation on an electrocardiogram (ECG).

In clinical cardiology, the contrast is between ST-elevation and non-ST-elevation conditions. ST-elevation myocardial infarction (STEMI) involves persistent ST-segment elevation on the ECG and requires rapid reperfusion. Non-ST-elevation myocardial infarction (NSTEMI) lacks ST elevations on the ECG but shows elevated cardiac biomarkers and has a similar risk profile and treatment considerations. The broader category of non-ST elevation acute coronary syndrome (NSTE-ACS) encompasses NSTEMI and unstable angina. Over time, clinicians commonly prefer NSTEMI and NSTE-ACS terms to describe the spectrum without relying on ST-elevation as the sole distinguishing feature.

Beyond cardiology, "nonST" may appear as an informal shorthand in other subfields to indicate non-ST criteria, but such usage is not standardized and can be ambiguous. For precise references, it is advisable to use specific terms like "non-ST-elevation," "ST segment," or the full acronyms NSTEMI or NSTE-ACS as appropriate.