Here is a review, available as free full text, along with a presentation of four cases.
Although the ECG lacks sensitivity and specificity and is not a “rule in” or “rule out” test for PE it is important for several reasons.
If the PE is massive or submassive it may provide diagnostic clues.
Massive and submassive PEs may be cause troponin elevation and electrocardiographic findings that superficially mimic MI. There are differences, however, that are worth knowing.
Here are a couple of my previous posts on the ECG in pulmonary embolism:  
Here is a post on the electrocardiographic distinction between ACS and PE.