Hi, Unlikely to be a foreign substance. cannot say in your particular case, but generally, quite a lot can occur from stimulants and many are quite serious consequences. First, heart attack can cause fluid retention, bloating and this may affect anywhere. It is common to have some increased fluid pressure backing up into the lungs and this produces a lot of different sensations including fullness in the throat. There can be local irritation or even damage in the nose and throat from the drug exposure. There can also be indirect effects like asthma that can cause sensations in the throat. The main points are these can be serious and all can be treated. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Matt Wachsman