Irregular heartbeats are very common. Frequently, it refers to an early beat or a skipped beat. Other than cause anxiety, it almost always is not a serious medical problem.
Very fast hearbeats can produce blood clots as the blood pools in the chamber for lack of time to adequately expel the blood from the chamber.
Very fast or very slow heartbeats are life threatening.
Depending on circumstances there may be a very slight probability that an irregular heartbeat if sustained can offset the normal effective timing causing a chaotic pattern of conduction of the electrical impulses that contract the heart muscles abnormally...if that situation, it may require a pacemaker, but I doubt that is your problem.