An arrhythmia is an abnormal heart beat. When everything is working well, the heart should maintain a steady, even beat. Arrhythmia occurs when the heart beats too quickly, too slowly, or erratically. The changes in heart rhythm can be caused by several different factors. Some medications speed up the heart rate. Smoking, stress, an imbalance in the electrolytes in your system, and heart disease can also change the heart rate.Some forms of arrhythmia, like premature atrial contractions that occur in the upper chambers of the heart, are not dangerous at all. Others, like a sudden rapid heartbeat (tachycardia) or an extremely intermittent or slow heartbeat (bradycardia), can cause a disruption in the heart's ability to deliver blood to the body's organs. If the disruption goes on for too long or severely impedes the blood flow to the extremities it can be very dangerous and lead to cardiac arrest.
