Causes of Palpitations
Sometimes the heart's electrical system breaks down or malfunctions, resulting in an abnormal heart beat. This may be a symptom of underlying coronary heart disease or other medical problems. Some causes of palpitations and abnormal heart rhythm are:
Irritable heart cells
Sometimes, some of the cells within the heart begin to malfunction, sending out electrical signals when they normally wouldn't. Signals from these malfunctioning cells interfere with the proper signals from the heart's natural pacemaker, 'confusing' the heart.
Blocked signals
Sometimes, the electrical signal which causes the heart to beat gets blocked, and may not reach the main pumping chambers of the heart (the ventricles). This causes the heart to pump very slowly (bradycardia).
Abnormal pathway
It's also possible for the heart beat signal to start out at the right place and time, but get interrupted and misdirected, rather than following the normal path.
Medications and stimulants
In some cases, certain medications and stimulants such as caffeine and nicotine can contribute to the development of an abnormal heart rhythm and can be causes of heart palpitations.