Predicting spontaneous reperfusion from the initial ECG

From a recent paper in AJC:

Inversion of the T waves (T−) in electrocardiographic leads with ST-segment elevation after the initiation of reperfusion therapy is considered a sign of reperfusion. However, the significance of T− on presentation before the initiation of reperfusion therapy is unclear. The aim of this study was to assess whether T− on presentation predicts patency of the infarct-related artery in patients with acute ST-segment elevation myocardial infarctions (STEMIs)...Patency of the infarct-related artery (Thrombolysis In Myocardial Infarction [TIMI] flow grades 2 and 3) was seen in 64.3% of the patients in the T− group compared with only 31.2% in the T+/− group and 19.0% in the T+ group (p less than 0.001). Among patients with anterior STEMI, patency of the infarct-related artery was seen in all 7 patients in the T− group, compared with 50% of the 4 patients in the T+/− group and 10.1% of the 79 patients in the T+ group (p less than 0.001). There were no significant differences in TIMI flow grade among the groups in patients with nonanterior STEMIs (p = 0.985). In conclusion, T− in the leads with maximal ST-segment elevation on the presenting electrocardiogram was associated with higher prevalence of patency of the infarct-related artery before intervention (64.3%), especially in patients with anterior STEMIs (100%).

I looked at the example ECGs provided in the full text of this paper. Distinguishing complete T wave inversion from biphasic T waves when marked ST elevation is present is tricky.