Based on the information his campaign has released, this scenario seems to be what happened to Bernie Sanders on Tuesday evening. Without a close look at Sanders’ medical chart, it’s impossible to make a definitive diagnosis, and I have not reviewed the details of his case other than what has been reported to the media by his campaign. But even the scant information we have—that he had stents inserted overnight following an acute cardiac episode—is enough to be able to say: This was very likely a heart attack.