Has your heart ever skipped a beat? Sometimes it really does if you have an arrhythmia. An arrhythmia is any disorder of your heart rate or rhythm. It means that your heart beats too quickly, too slowly or with an irregular pattern. When the heart beats faster than normal, it is called tachycardia. When the heart beats too slowly, it is called bradycardia. Many factors can affect your heart's rhythm, such as having had a heart attack , blood chemistry imbalances or abnormal hormone levels. Some substances or medicines may also cause arrhythmias. Symptoms of arrhythmias include Fast or slow heart beat Skipping beats Lightheadedness, dizziness Chest pain Shortness of breath Paleness Sweating Your doctor can run tests to find out if you have an arrhythmia. Treatment to restore a normal heart rhythm may include medicines, an implantable cardioverter-defibrillator (ICD) or a pacemaker .