there can be two possibility to your condition either you have heart condition or you have anxiety
problem which psychological.
now for heart problem you will have to visit a cardiologist who will evaluate you properly and rule out causes like arrhythmia
,if every thing is normal in your heart than i suggest you go to psychiatrist
, it looks more like anxiety problem to me than heart, also when you go to cardiologist kindly show him the medication your taking for asthma
, because a few orally taken medication can cause the symptoms like yours.