If you have a history of psvt or ist, the sudden change in symptoms can be due to the same reason. B blockers are prescribed in patients with these conditions. The best thing to do right now is to consult a physician and understand why is this happening. If pulse rate is high, it’s something you should get checked in person and as soon as possible
Next Steps
Consult a physician and get an ECG done.
Health Tips
Do not take any medications without consulting a physician in person.