Greetings. Thank you for your question and welcome to HCM. I understand your concern.
If this pain did not go away with your antibiotic therapy then probably it was not a
sore throat.
Angina, pain originated by a blockage in your coronary arteries (arteries that encompass the heart as a crown, and "feed" it with
oxygen and nutrients), usually manifests as a mid-
chest pain radiating to the throat and left arm or shoulder. However, sometimes it can have atypical forms of manifesting and, since you have this sensation during carrying out physical activity, such as climbing stairs, my opinion is that you should have a cardiac check-up to, at least, exclude the cardiac origin of this pain. This is what I recommend you to do. First, to
consult a cardiologist and have an EKG and an
echocardiogram, to assess your heart electrical system and conduction system, and also assess the motility and function of heart chambers and valves. If seen appropriate, proceed further with a cardiac
stress test, do more sensitively and specifically depict any problem in your coronary arteries. With your symptom, if the latter test comes back positive or inconclusive, then a coronary angiogram is appropriate, to assess if there are blockages in your coronary arteries and, if there are, to be treated as recommended.
I hope I was helpful. Take care and good luck.
Best regards,
Dr. Meriton