Non ST elevation Myocardial infarction (NSTEMI) is a major mode of presentation of acute coronary syndrome.
Patients present with clinical unstable angina and elevated cardiac enzymes or troponin.
ECG features can be any of the following.
1.ST depression (70-80%)
2.T wave inversion(10-20%)
3.Both ST depression and T wave inversion
4Post MI NSTEMI -ECG changes variable ( Ironically ,even a residual ST elevation may be present)
Bulk of the NSTEMI belong to ST depression group.NSTEMI with purely T wave inversion is less common but occurs mainly in perioperative settings, pre existing CAD.NSTEMI with normal ECG is very rare but can occur.