There are several reasons for a fast heartbeat in bronchitis: 1. Fever, if bronchitis is combined with fever, can cause a fast heartbeat, because for every 1 degree increase in body temperature, the heart rate increases at least 10 times, so in this case anti-fever treatment is possible. 2. When bronchitis is present, there may be a viral infection in the early stages and a mycoplasma or serious bacterial infection in the later stages, which may cause damage to the heart muscle. In the case of myocardial damage, you need to go to the hospital to check the cardiac enzymes to see if you need to use drugs for the heart to nourish the heart muscle. Usually, fast heartbeat caused by bronchial is the first case, that is, fast heartbeat caused by fever combined. If it is bronchitis, coughing more violent, will also cause a fast heartbeat, so the fundamental thing is to treat bronchitis. However, if the heartbeat is fast enough to make you panic and feel uncomfortable, you can use a small amount of Betalac to control your heart rate and make yourself comfortable.