I'm A Healthy 54 Year Old Woman. I Went To

I'm a healthy 54 year old woman. I went to the ER with chest pain after swimming. My cardiac enzymes were 111. I was told I had a mild heart attack. My heart tests all and back fine so they told me my heart was stressed due to lack of oxygen as an undiagnosed asthmatic. I'm now on 4 puffers, steroid nasal spray and oral steroids. Have you ever heard of this?