When the heart needs help to beat

When you are at rest, your heart should beat between 60 to 100 times a minute. But one can develop conditions, like arrhythmia, where the heart beats too fast, too slow or is just irregular. 

Arrhythmia is caused by changes to heart tissue and can be triggered by stress, medicines or imbalances in the blood. When your heart beats irregularly, it may not be able to pump enough blood causing fatigue, shortness of breath or fainting.