Sudden intolerance to alchohol, any help?

My friend was able to drink fine until about a year ago, when she took 2 shot of tequila and had some of the worst heart pains in her life. She said it lasted about 5-10 minutes, could’ve been heartburn but she doesn’t think it was. After that, she tried taking a half shot of whiskey and the same thing happened. She woke up the next morning feeling incredibly hungover and throwing up a lot (which is unusual since she never tended to get hangovers, especially since it was only 2 and a half shots)

Ever since, she hasn’t been able to drink without that heart pain. A few months after the first incident, she tried some champagne, and just a few sips gave her the same heart pain, though not as bad.

After about a year, shes been trying small sips of drinks with little issue. Small sips of: drinks with vodka; white claws;piña colada; all of which she was fine for. But yesterday while we were at a party, she drank a white claw and a couple piña coladas (which had maybe about an ounce of rum each) and the same heart pain came back, about the same as the first time.

We both hope she’ll be able to drink again normally, but are confused as to how this intolerance came completely out of nowhere, and if it will someday go away. Does anybody know what this could be and how to help it? Thanks!

If it helps: She is in her 20s She is of german descent

main points: – after being able to drink fine, suddenly about a year ago my friend couldn’t drink without getting heart pain – small sips and canned drinks seemed to be fine (to a degree), but after a little too much, the heart pain comes back – curious if theres a way to remedy, or if its something that will eventually go away?