Arrhythmia (Heart Rhythm)

Heart rhythm problems, or heart arrhythmias, 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 they may be harmless. However, some heart arrhythmias can cause bothersome — sometimes even life-threatening — signs and symptoms. However, arrhythmias may not cause any signs or symptoms.

Your health care provider may find that you have an arrhythmia before you do during a routine examination. Noticeable signs and symptoms don't necessarily mean you have a serious problem.

Noticeable arrhythmia symptoms can include:

• A fluttering in your chest
• A racing heartbeat
• A slow heartbeat
• Chest pain
• Shortness of breath

Causes and risk factors

Certain conditions can increase your risk of developing an arrhythmia, including:

• Coronary artery disease, other heart problems and previous heart surgery — narrowed heart arteries, a heart attack, abnormal heart valves, prior heart surgery, heart failure 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 of arrhythmias.
• Diabetes — your risk of developing coronary artery disease and high blood pressure greatly increases with uncontrolled diabetes.
• Obstructive sleep apnea — this disorder, where your breathing is interrupted during sleep, can increase your risk of bradycardia, atrial fibrillation (A-fib) and other arrhythmias.
• Electrolyte imbalance — substances in your blood called electrolytes, such as potassium, sodium, calcium and magnesium, 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.

Treatment

Cardiac ablation

Cardiac ablation works by scarring the tissues in your heart that trigger the abnormal heart rhythm. In some cases, it prevents abnormal electrical signals from entering your heart and stops the arrhythmia.

Cardiac ablation uses long, flexible tubes inserted through a vein or artery in your groin, and threaded to your heart to deliver heat or cold to modify the tissues in your heart that are causing the arrhythmia.

Implantable devices

Treatment for heart arrhythmias also may involve use of an implantable device:

• Pacemaker — a pacemaker is an implantable device that controls abnormal heart rhythms. A small device is placed under the skin near the collarbone in a minor surgical procedure. An insulated wire extends from the device to the heart, where it's permanently anchored.
  If a pacemaker detects a heart rate that's abnormal, it emits electrical impulses that stimulate your heart to beat at a normal rate.
• Implantable cardioverter-defibrillator (ICD) — your health care provide may recommend this device if you're at high risk of developing a dangerously fast or irregular heartbeat in the lower half of your heart. An implantable cardioverter-defibrillator is a battery-powered unit that's implanted under the skin near the collarbone — similar to a pacemaker. One or more electrode-tipped wires from the implantable cardioverter-defibrillator run through veins to the heart. The implantable cardioverter-defibrillator continuously monitors your heart rhythm.
  If it detects an abnormal heart rhythm, it sends out low- or high-energy shocks to reset the heart to a normal rhythm. An implantable cardioverter-defibrillator doesn't prevent an abnormal heart rhythm from occurring, but it treats it if it occurs.