Can respiratory problems stem from sinus tachycardia?

     I have just recently found out that I have sinus tachycardia, and I am on the beat blocker Atenolol.  Although I think I may have had it for maybe like 7 months.  Because I have been constantly tired for around that long.  It started randomly when I was at my church's evensong.  I was singing in the choir, and all of a sudden I started getting this "weird" feeling.  I put weird in quotes because i had never felt that feeling before.  It was a mix between the feeling before passing out and something else, but I knew I wasn't going to pass out, it wasn't that type of feeling.  So I went to a cooler area and had some water and just rested for about five minutes, and the feeling wasn't going away.  The next thing I did was check my heart rate and it was 100 BPM.  That was my resting heart rate.  All I did that day was sing.  So my first question is how does an irregular heart beat just pop up like this?
     My next question has to deal with some respiratory issues.  I have been noticing that the littlest things, such as walking up a flight of stairs, causes me to fee out of breath.  I have gone to the doctor and she has diagnosed it as exertional dyspnea, but I am wondering how that relates to the heart?  My assumption is that my heart isn't pumping enough oxygen to my lungs.  
     Another thing i have noticed is that I am having issues with my breathing at night.  It just recently started where I was having trouble breathing while lying in bed.  I was lying flat on my stomach like I always do, and I started to notice that my breaths were not normal.  When I was breathing out, I felt as if literally all the air was out of my lungs.  Yet when i breathed in, I was breathing in short, fast pased breaths.  What scared me the most was at one point when I was breathing out, I couldn't breath back in for like eight seconds.  And after I finally did, I got hot then cold and then my heart started racing.  My doctor said I could have blacked out for like a second or two, but I am not sure since I sleep in the dark.  I noticed though that sitting at a semi upright position didn't cause this.  I found this out by my choice to sleep on the couch.  So I guess it only happens when I lay flat on my stomach because I am not sure if it happens when I lay on my back because I don't like to sleep on my back.  I just want to know what is going on with me, and I was wondering if you could tell me?

Thank you.  
    


This discussion is related to Various cardiac symptoms.

[paanda2]

i am curious about this as well. i'm on atenolol as well, for IST (inappropriate sinus tachycardia) and sometimes i have breathing issues as well. i don't feel particularly winded (i live on the 3rd floor of an apt building and can walk up the stairs just fine; i feel a little bit in need of more air, but nothing bad at all; i'm just out of shape ;)). but sometimes i feel like i'm not getting enough air/need to take bigger/more breaths. this is usually while doing nothing. i don't feel this particularly while laying down though. that i would talk to your dr about.

my dr tested my lungs and they were fine. but i think that sinus tachycardia can make a person particularly breathless, although i feel this way when my hr is normal...i don't know. i think it may be an unexplained side effect. i am getting a second opinion/new dr in may, and i will ask then.

i don't know what exertional dyspnea is, but maybe it's because when you exert yourself, your heart pumps faster/harder which makes you short of breath?