Heart arrhythmia is a condition where the heart beats irregularly, too fast, or too slow. A regular heart rhythm is the ideal pattern, where the heart beats in a steady and consistent manner. Bradycardia is a type of arrhythmia where the heart beats too slowly, while tachycardia is a type where the heart beats too quickly. Fibrillation is another type of arrhythmia where the heart beats irregularly and too fast, which can be very dangerous and increase the risk of a stroke or heart failure.