human
My doctor says I have an irregular heartbeat. What is a cardiac arrhythmia?
assistant
A cardiac arrhythmia is a disturbance in the heart rate or rhythm. It can be caused by problems with the electrical conduction system of the heart, which carries signals from the atria and ventricles to the rest of the body. Cardiac arrhythmias can also be caused by abnormal impulse formation within the heart muscle itself. Common types of arrhythmias include atrial fibrillation (AF), sinus tachycardia, premature ventricular contractions (PVCs) and premature atrial contractions (PACs).