Normally, the heart muscle squeezes and relaxes in a steady, predictable pattern, controlled by electrical signals. When something goes wrong with the heart’s electrical system, the heart may feel like it’s beating too fast (sinus tachycardia), too slow (bradycardia), or out of rhythm.
There are lots of different types of arrhythmias, depending on their exact cause. Two common types are atrial fibrillation and atrial flutter.
Many arrhythmias are harmless, and don’t need special care. But some can lead to health problems, and need to be treated. So it’s always important to have them checked out by a heart doctor.