If this is a one time occurrence it may mean little or nothing. This is especially true if you are very young. If it happens again it should be investigated. The fact that it occurred when you were lying down is of some concern, unless you were very excited because of the X-box game you were playing. It might be prudent of you to schedule an appointment with your doctor. Explain the occurrence very carefully in as much detail as you can remember. The doctor may want to take an ECG to check your heart for any abnormalities. The ECG can show an abnormality, if any exists, even though you are experiencing no symptoms at the time. There appears to be no need for worry but a little preventive care can mean a lot to your future health. Your cold
should not have had anything to do with your heart.