Hello and thanks for writing in
It is our body normal phenomenon that heart rate and breathing rate always increases after exertion like climbing the stairs. Don't worry about the increased heart rate but if it occurs even in resting position than you needs to be investigated for PSVT or AF.
Now regarding spot in the lung, it needs to be investigated. It can be due to any bacterial infection, Bronchial Pneumonia and needs a course of antibiotic and than repeat X-ray again. Consult your treating doctor and go through some investigations like Complete blood Count, CT Chest and TB Elisa.
Best Wishes

Dear friend, welcome and thanks for entrusting your query here at HCM !

Fast heart rate is a normal response after strenous activity.
If you feel unusually breathless too, it could be of respiratory origin.

One sputum negativitiy does not rule out TB. you need at least 3 consecutive sputum samples to be tested.

Xray finding can have many differentials.
Please discuss differentials and further testing with your doctor.
If possible, could post your Xray image here so that I can comment better?
Please describe each symptom in great detail.

I hope you are fully satisfied with the guidance I gave.
I would be glad to answer any further queries.
Thank you and Good luck !

Hi

Thanks for your query

Its very usual to have fast beating heart after climbing rushing up a 5-stairs building due to sinus tachycardia. Though you may have an ECG to exclude underlying heart abnormality for this fast hear beat.

Many a times sputum examination may be normal but anti-tubercular drugs may be given on the basis of radiological finding if radiological lesion is suspicious of tuberculosis. You may have a mantoux test. If mantoux reading is positive then better to continue anti-tubercular drugs (ATD) and as you have already started ATD it will be wise to complete its 6 months course in oreder to prevent drug resistance and until your physician is able to establish an alternative diagnosis.

Thank you.