Prognostic Value of ST Elevations in Myocardial Infarction

Anterior location of STE (anterior AMI) compared with inferior or lateral, correlates with much worse prognosis and greater benefit of reperfusion therapy

Patients with anterior infarction demonstrated a lower left ventricular ejection fraction on admission and after 10 days than did patients with inferior infarction, even after adjustment for infarct size, as well as a higher incidence of congestive heart failure and cumulative cardiac mortality.

Reference:
1. Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.

2. Stone PH, Raabe DS, Jaffe AS et al. Prognostic significance of location and type of myocardial infarction: independent adverse outcome associated with anterior location. J Am Coll Cardiol 1988; 11 (3):453-63.

ST Score

Greater height of ST segments and greater number of leads involved correlate with higher mortality and greater benefits from reperfusion therapy.

ST Score refers to the total millimeters of STE in all leads combined. High ST Score correlates with higher mortality

Measured at J point, a score greater than 12 to 13 mm for anterior AMI and greater than 6 – 9 mm for inferior AMI correlates with high risk of early complications

For example, in a study by Gwechenberger et al, a cutoff value of 13 mm for anterior MI and 9 mm for inferior MI stratifies patients into high- and low-risk subgroups for the development of acute congestive heart failure and severe rhythm disturbances during the first 24 hours of hospitalization.


References:
1. Chan TC, Brady WJ, Harrigan RA et al. ECG in Emergency Medicine and Acute Care. 1st ed. Pennsylvania: Elsevier Mosby; 2005.

2. Gwechenberger M, Schreiber W, Kittler H et al. Prediction of early complications in patients with acute myocardial infarction by calculation of the ST score. Ann Emerg Med 1997; 30 (5):563-70.