Hi, If you are experiencing the abnormal heartbeat so it may not be the normal one and it has to be investigated for the underlying cause. Most of the time it can be due to stress and anxiety but it has to be ruled out for cardiac disease first. Masturbation can increase the heart rate or may break the normal rhythm for a while but it is the physiological phenomenon until and unless proved some cardiac disease. Hope I have answered your query. Let me know if I can assist you further.