Risk factors

Things that may increase the risk of heart arrhythmias 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 condition increases the risk of developing coronary artery disease. It may also cause the walls of the left lower heart chamber (left ventricle) to become stiff and thick, which can change how electrical signals travel through the heart.
• Congenital heart disease. Being born with a heart condition may affect the heart's rhythm.
• Thyroid disease. Having an overactive or underactive thyroid gland can raise the risk of irregular heartbeats.
• Obstructive sleep apnea. This condition causes pauses in breathing during sleep. It can lead to a slow heartbeat (bradycardia) and irregular heartbeats, including atrial fibrillation.
• Electrolyte imbalance. Substances in the blood called electrolytes — such as potassium, sodium, calcium and magnesium — help trigger and send electrical impulses in the heart. An imbalance in electrolytes — for example, if they are too low or too high — can interfere with heart signaling and lead to irregular heartbeats.
• Certain drugs and supplements. Some prescription drugs and certain cough and cold medications bought without a prescription can cause arrhythmias.
• Excessive alcohol. Drinking too much alcohol can affect the electrical impulses in your heart and can increase the chance of developing atrial fibrillation.
• Caffeine, nicotine or illegal drug use. Caffeine, nicotine and other stimulants can cause your heart to beat faster and may lead to the development of more-serious arrhythmias. Illegal drugs, such as amphetamines and cocaine, may greatly affect the heart and cause many types of arrhythmias or sudden death due to ventricular fibrillation.