Even if your heart is healthy, you could develop an arrhythmia. It could also happen as a result of: Cardiovascular disease, An electrolyte imbalance (such as sodium or potassium) in your blood, Heart injury or alterations, such as diminished blood flow or stiff heart tissue, are examples of heart injury or changes. The recovery period following heart surgery, Fever, or infection Certain drugs, for example, Problems with your heart's electrical signals Strong feelings, worry, or surprise Things you use on a daily basis, such as alcohol, tobacco, caffeine, or exercise