An arrhythmia is a condition in which your heart beats too fast, too slow or erratically due to a problem with your heart’s electrical system.

Your heartbeat is controlled by special nerve cells that emit electrical signals, which cause your heart to contract and pump blood. If the nerve cells aren't working properly or the signals don't travel normally through your heart, it can cause an arrhythmia. An arrhythmia can also occur if cells in another part of your heart begin producing electrical signals that disrupt the normal heartbeat.

During an arrhythmia, your heart isn't able to pump enough blood to your body, which can damage your brain, heart and other organs.

Types of Arrhythmias

Most arrhythmias are harmless, but some can be serious or even life threatening. There are four main types of arrhythmias:

  • Premature beats. The most common type of arrhythmia, premature beats are typically harmless and usually don't cause symptoms or require treatment. If there are symptoms, you might feel like your heart is fluttering or skipping a beat. Usually, they occur naturally, but they can also be caused by heart disease or because of too much stress, exercise, or caffeine or nicotine.
  • Supraventricular arrhythmias. These arrhythmias are characterized by a very fast heartbeat and can be serious. They include atrial fibrillation (AF) — which is the most common type of serious arrhythmia — atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and Wolff-Parkinson-White (WPW) syndrome.
  • Ventricular arrhythmias. Ventricular tachycardia and ventricular fibrillation (v-fib), in which signals occur at a very fast rate, can be very serious and cause sudden cardiac arrest. Sudden cardiac arrest can cause death within a few minutes if not treated, but the condition can be reversible if the heart is restarted with CPR or an automated external defibrillator (AED).
  • Bradyarrhythmias. When the heart beats slower than normal, it's called a bradyarrhythmia or bradycardia. If the rate is too slow, not enough blood reaches your brain and it can cause you to pass out. Bradyarrhythmias can be caused by a heart attack, a chemical imbalance, certain medications or conditions that change your heart's electrical activity, such as aging or an underactive thyroid.


One of the best ways to reduce your risk of arrhythmias is to take the same steps you’d take to lower risk of coronary artery disease. Arrhythmias are most common in people with a history of heart attack, heart failure, valve problems or congenital heart defects. High blood pressure, atherosclerosis, diabetes, sleep apnea and thyroid conditions can also increase your risk of developing arrhythmias.

Making heart-healthy lifestyle choices can help lower your risk of developing an arrhythmia. Eating well, controlling your weight, avoiding smoking, managing stress, and limiting alcohol, caffeine and other substances that may contribute to arrhythmias and heart disease can help minimize your risk. The Norma Melchor Heart & Vascular Institute at El Camino Health offers a variety of classes and programs to help you adopt heart-healthy behaviors — including services to help you quit smoking.

If you have any existing risk factors, follow your doctor's advice to maintain good health and prevent arrhythmias. Have regular checkups to manage your health, and make sure you mention any new symptoms or changes in your health or medications during your visit.


In many cases, arrhythmias have no symptoms. When symptoms do occur, you might feel very fast or slower-than-normal heartbeats, irregular heartbeats or a pause between beats. More serious symptoms include:

  • Weakness and light-headedness
  • Fainting
  • Sweating
  • Shortness of breath
  • Chest pain

If you experience these symptoms, talk to your doctor. Although many types of arrhythmia don't pose a danger, ventricular tachycardia and ventricular fibrillation can lead to sudden cardiac arrest, and atrial fibrillation can increase your risk of developing blood clots that can lead to a stroke.

Not all arrhythmias require treatment. In some cases, your doctor may prescribe medicine to treat underlying conditions, but medicines can only offer limited treatment for arrhythmias.

If your condition requires treatment, El Camino Health offers some of the latest therapies. Our arrhythmia experts specialize in advanced approaches, including implantable devices and radiofrequency ablation. Our heart and vascular specialists offer you some of the latest treatments, including maze heart surgery and LARIAT® and WATCHMAN™ devices for atrial fibrillation.