5. Rapid Heartrate
An elevated heart rate is not so much a symptom of RSV but of any condition like this. Your heart rate will often increase whenever your breathing speeds up. This is because the increased, rapid breathing will send a signal to the vagal nerve, which in turn will trigger the release of hormones and neurotransmitters such as adrenaline, norepinephrine, cortisol, etc.
At the same time, the heart rate may be elevated as a result of the increased body temperature, or as a result of the infection itself. Essentially the body is now under stress and is fighting to get back to full health. You should find that this is a relatively minor change however unless you are experiencing a more severe form of infection.