A heart rhythm disorder is also known as a heart arrhythmia, cardiac ectopy, or dysrhythmia. Heart rhythm problems occur when the electrical impulses that coordinate your heartbeats don't work properly, causing your heart to beat too fast, too slow or irregularly. Heart arrhythmias may feel like a fluttering or racing heart and may be harmless. However, some heart arrhythmias may cause bothersome — sometimes even life-threatening — signs and symptoms. About 2.2 million Americans have atrial fibrillation, including 3 percent to 5 percent of people over 65.

Arrhythmias may not cause any signs or symptoms. In fact, your doctor might find you have an arrhythmia before you do, during a routine examination. Noticeable signs and symptoms don't necessarily mean you have a serious problem, however. Noticeable arrhythmia symptoms may include a fluttering in your chest, a racing heartbeat (tachycardia), a slow heartbeat (bradycardia), chest pain, shortness of breath, lightheadedness, dizziness, or fainting (syncope) or near fainting.

Many things can lead to, or cause, an arrhythmia, including a heart attack that's occurring right now, scarring of heart tissue from a prior heart attack, changes to your heart's structure, such as from cardiomyopathy, blocked arteries in your heart (coronary artery disease), high blood pressure, diabetes, overactive thyroid gland (hyperthyroidism), underactive thyroid gland (hypothyroidism), smoking, drinking too much alcohol or caffeine, drug abuse, stress, certain prescription medications, certain dietary supplements and herbal treatments, electrical shock, and air pollution.

Certain factors may increase your risk of developing an arrhythmia. These include:

·         Coronary artery disease, other heart problems and previous heart surgery. Narrowed heart arteries, a heart attack, abnormal heart valves, prior heart surgery, heart failure, cardiomyopathy and other heart damage are risk factors for almost any kind of arrhythmia.

·         High blood pressure. This increases your risk of developing coronary artery disease. It may also cause the walls of your left ventricle to become stiff and thick, which can change how electrical impulses travel through your heart.

·         Congenital heart disease. Being born with a heart abnormality may affect your heart's rhythm.

·         Thyroid problems. Having an overactive or underactive thyroid gland can raise your risk for arrhythmias.

·         Drugs and supplements. Certain over-the-counter cough and cold medicines and certain prescription drugs may contribute to arrhythmia development.

·         Diabetes. Your risk of developing coronary artery disease and high blood pressure greatly increases with uncontrolled diabetes.

·         Obstructive sleep apnea. This disorder, in which your breathing is interrupted during sleep, can increase your risk of bradycardia, atrial fibrillation and other arrhythmias.

·         Electrolyte imbalance. Substances in your blood called electrolytes — such as potassium, sodium, calcium and magnesium — help trigger and conduct the electrical impulses in your heart. Electrolyte levels that are too high or too low can affect your heart's electrical impulses and contribute to arrhythmia development.

·         Drinking too much alcohol. Drinking too much alcohol can affect the electrical impulses in your heart and can increase the chance of developing atrial fibrillation.

·         Caffeine or nicotine use. Caffeine, nicotine and other stimulants can cause your heart to beat faster and may contribute to the development of more-serious arrhythmias. Illegal drugs, such as amphetamines and cocaine, may profoundly affect the heart and lead to many types of arrhythmias or to sudden death due to ventricular fibrillation.