Extreme shortness of breath - no stamina

[SOBstory]

I was diagnosed with mild coronary artery disease 18 month ago and prescribed daily aspirin and statins. The condition didn't affect my fitness or stamina and I regulary exercised, cycled and enjoyed fell walking.

Since having a prostrate biopsy earlier this year, I have been unable to do anything strenuous without becoming very short of breath (SOB). Climbing stairs is now as strenuous to me as climbing Hellvelyn was a year ago. Trying to regain any fitness or stamina by 'increased activity just makes things worse. . I get no angina type pain and tests for blood clots (d-dimer tests and a CTPA scan), echocardiogram and lung function tests have shown nothing. Some irregularities on ECG monitoring such as RBBB were said to be ' fairly normal' and a recent angiogram resulted in 'unobstructed coronaries but sluggish flow'. No stent needed but I've been prescribed Diltiazem . After a month on Diltiazem I'm no better (if anything worse) than before the angiogram. My next contact with cardiology is in 3 months time for another echocardiogram, but I have little expectation of progress.

My oncology consultant says the SOB is nothing to do with my malign prostrate. Hormone treatment for the prostrate started in June and has no adverse effect on my condition. Radiotherapy is still a few months away.

I would love to hear from someone who has heard of or experienced something similar or has any ideas re my SOB condition.