I'm not a doctor nor any kind of medical professional, but it's hard to see how bronchitis would have anything to do with feeling like your heart was beating too fast. It also doesn't mean it actually was beating fast -- anxiety makes us think things are happening that might not be actually happening. But bronchitis refers to inflamed bronchia, which you would feel all the time and would make taking a breath more difficult, such as when you have a chest cold. Since you're posting on the anxiety forum, I'm assuming you have an anxiety problem or suspect one, and you're describing a common feeling people get when they feel especially anxious. That would make the treatment treating the anxiety, not the symptom.