What are the different types of arrhythmia?

Dr. Imran A. Niazi, MD
Cardiac Electrophysiologist

The term arrhythmia means "lack of rhythm," and refers specifically to the heart rhythm, which is normally very regular.

The heart rhythm can become irregular due to extra beats (PVCs or premature ventricular contractions, previously called "extra systoles"). They are generally benign. The heart can beat too rapidly (tachycardia) or too slowly (bradycardia). It can even stop (asystole), generally with disastrous consequences.

Each arrhythmia has its own risks, and specific treatment is available for all of them. If the heart beats too slow, or tends to stop, it is treated with a pacemaker. If the heart beats too fast and causes unconsciousness due to inadequate blood supply to the brain, it is generally treated with a defibrillator. A heart that beats too rapidly can lead to cardiac arrest, a highly lethal condition that occurs in almost 350,000 people annually in the U.S.

Sometimes, the heart beats fast AND irregular; this is called atrial fibrillation, and is a very common arrhythmia. While not usually lethal, it can lead to stroke, so treatment is necessary.

Contact your doctor if you have very rapid heartbeat, fainting spells or simply a very irregular pulse. A diagnosis usually can be quickly made and treatment started.

The four main types of arrhythmia are premature beats, supraventricular arrhythmias, ventricular arrhythmias, and bradyarrhythmias.

Premature Beats
Premature beats are the most common type of arrhythmia. They're harmless most of the time and often don't cause any symptoms.

When symptoms do occur, they usually feel like fluttering in the chest or a feeling of a skipped beat. Most of the time, premature beats need no treatment, especially in healthy people.

Premature beats that occur in the atria are called premature atrial contractions, or PACs. Premature beats that occur in the ventricles are called premature ventricular contractions, or PVCs.

Supraventricular Arrhythmias
Supraventricular arrhythmias are tachycardias that start in the atria or the atrioventricular (AV) node. The AV node is a group of cells located between the atria and the ventricles.

Types of supraventricular arrhythmias include atrial fibrillation (AF), atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and Wolff-Parkinson-White (WPW) syndrome.

Ventricular Arrhythmias
These arrhythmias start in the ventricles. They can be very dangerous and usually need medical attention right away.

Ventricular arrhythmias include ventricular tachycardia and ventricular fibrillation (v-fib). Coronary heart disease, heart attack, weakened heart muscle, and other problems can cause ventricular arrhythmias.

Bradyarrhythmias are arrhythmias in which the heart rate is slower than normal. If the heart rate is too slow, not enough blood reaches the brain. This can cause you to lose consciousness.

Bradyarrhythmias can be caused by:

  • Heart attack
  • Conditions that harm or change the heart's electrical activity, such as an underactive thyroid gland or aging
  • An imbalance of chemicals or other substances, such as potassium, in the blood Some medicines, such as beta blockers

Arrhythmias in Children
Some children are born with heart defects that cause arrhythmias. In other children, arrhythmias can develop later in childhood. Doctors use the same tests to diagnose arrhythmias in children and adults.

This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.

There are several different types of arrhythmias, a condition associated with irregular or abnormal heart beat rates. Arrythmia is classified as atrial (arising from the upper chambers of the heart) or ventricular (arising from the lower chambers of the heart). The arrythmias arising from the upper chambers of the heart are not life threatening but can be difficult to treat. These include atrial fibrillation and atrial flutter. Several types of medications are used to keep the heart rate controlled and to convert the arrhythmia into normal rhythms. Blood thinning medications are usually used in patients with long-term atrial arrythmias due to the risk of clots forming in the heart and the potential for stroke.

Ventricular arrhythmias, which originate in the lower chambers of the heart, are potentially more serious and life threatening. Ventricular tachycardia, characterized by a heart rate of between 125 and 250 beats per minute, can be treated with medication, but may require placement of an internal defibrillator to shock the heart if this arrhythmia persists. Ventricular tachycardia can worsen and head to ventricular fibrillation, which is also treated by shocking the heart. If left untreated, ventricular fibrillation will result in death.

Disturbances of the electrical pacemaker of the heart (sinus node dysfunction) and disturbances of the conduction system of the heart (heart block) are other types of arrhythmias that may require pacemaker placement.

Dr. Andrea C. Bryan, MD
Cardiologist (Heart Specialist)

Arrhythmias, or heart rhythm disorders, can be electrical, circulatory, or structural in origin. These can originate from the upper chambers of the heart, or atria, or the lower chambers, the ventricles. Some common arrhythmias include atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia and ventricular fibrillation.

The contents of this website are for informational purposes only and are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Nor does the contents of this website constitute the establishment of a physician patient or therapeutic relationship. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Dr. Vivek Y. Reddy, MD
Cardiac Electrophysiologist

Arrhythmias cause a variety of problems that range from mild to severe:

  • Premature heartbeats
  • Atrial fibrillation and atrial flutter
  • Paroxysmal supraventricular tachycardia
  • Wolff-Parkinson-White syndrome
  • Ventricular tachycardia
  • Ventricular fibrillation
  • Bradycardia

There are two main categories of arrhythmias. Those that begin in the atria, or upper chambers of the heart, are called supraventricular arrhythmias. These include atrial fibrillation, atrial flutter, sick sinus syndrome and sinus tachycardia. Arrhythmias that begin in the ventricles, or lower chambers of the heart, are called ventricular arrhythmias. These include ventricular tachycardia, ventricular fibrillation and long QT syndrome.

Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

If everyone is doing a choreographed dance routine and you're out of step, then you can understand what an arrhythmia is. When it comes to your heart being out of sync, an arrhythmia can mean that the heart beats too fast, too slow, or it beats erratically. Some arrhythmias are benign (won't cause you harm), while others are life-threatening.

Here are some different types of arrhythmias:

  • Atrial fibrillation, in which the atria or top part of the heart quivers;
  • Bradycardia, in which the heart beats too slowly;
  • Tachycardia, in which the heart beats too fast;
  • Premature contractions, in which the heart beats too early in its cycle;
  • Ventricular tachycardia, in which the ventricles beat too quickly (this is life-threatening, so your doctor will want to control this);
  • Ventricular fibrillation, in which the entire heart fibrillates or quivers. This is life-threatening and you will die unless your heart can get an electrical shock right away to reset it.
Dr. Douglas E. Severance, MD
Family Practitioner

There are different types of arrhythmias. Experts classify arrhythmias by how fast or slow the heart rate is and by the place of origin of the arrhythmia. For instance, a very slow heartbeat, or one that's under 60 beats per minute at rest, is called bradycardia. A rapid heart rate that is higher than 100 beats per minute at rest is referred to as tachycardia. If you have tachycardia or bradycardia, that does not mean you have heart disease. Your doctor can check your heart using medical tests to make sure everything is normal. Some healthy individuals experience a rapid heartbeat (tachycardia) during intense exercise. The heartbeat speeds up and sends oxygenated blood to all of the body's tissues.

The main types of cardiac arrhythmias, or heart rhythm disturbances, include:

  • Tachycardia: a fast heart rhythm (more than 100 beats per minute)
  • Bradycardia: a slow heart rhythm (fewer than 60 beats per minute)
  • Supraventricular arrhythmias: abnormal rhythms that begin in the heart’s upper chambers (atria)
  • Ventricular arrhythmias: arrhythmias that begin in the heart’s lower chambers (ventricles)
  • Bradyarrhythmias: slow heart rhythms that usually are caused by a disease in the heart’s conduction system

This content originally appeared online in "The Patient Guide to Heart, Lung, and Esophageal Surgery" from the Society of Thoracic Surgery.

There are many different types of cardiac arrhythmias ranging from the completely benign to the immediately life threatening. Arrhythmia simply means "abnormal heart rhythm."

Sinus arrhythmia is a common, completely benign rhythm disturbance where breathing in and out alters the heart rate -- typically the heart rate briefly accelerates during inspiration and briefly decelerates during expiration.

Premature atrial contractions (PACs) are generally benign electrical signals originating in the upper chambers of the heart (the atria) that may cause the sensation of a "skipped" heart beat. PACs may initiate other arrhythmias such as atrial fibrillation, atrial flutter, or SVT though this is the exception rather than the rule. PACs are common and generally do not necessitate treatment unless they are highly symptomatic or are recurrently triggering other arrhythmias.

Premature ventricular contractions (PVCs) are premature heart beats originating in the lower chambers of the heart (the ventricles). PVCs may cause the sensation of a "skipped" heart beat. PVCs are generally benign though in the setting of a heart attack, a severely weakened heart, or severe structural heart disease they may be a prognosticator of potentially life-threatening rhythm problems.

SVT stands for supraventricular tachycardia which is a "catch-all" term for inappropriate fast heart rhythms that originate from the upper chambers (or atria) of the heart. SVTs may produce symptoms ranging from palpitations to dizziness to shortness of breath.

Atrial fibrillation is a totally disorganized, chaotic rhythm in the atria that frequently causes the heart to beat fast and irregularly.

Atrial flutter is an organized, regular short circuit in the atria that tends to cause the heart to beat fast and regularly. Both atrial fibrillation and flutter may increase the risk of stroke.

Ventricular tachycardia (VT) is a fast heart rhythm originating from the lower chambers of the heart. VT may be life threatening in the setting of a heart attack, a weakened heart, or severe structural heart disease. There are also benign forms of VT.

Ventricular fibrillation is an immediately life-threatening rhythm where the heart stops effectively pumping blood.

Heart block: Heart block means there is ineffective transmission of electrical signals within different area of the heart ranging from benign to immediately life-threatening. This should not be confused with blockage in a heart artery.

Arrhythmia is the abnormal beating of your heart. Arrhythmias are classified by where the condition originates and whether the heart beats faster or slower than normal. Supraventricular Tachycardia is rapid beating that originates in the upper chambers of the heart. It is the most common arrhythmia in young adults, and most cases are curable with ablation. Ventricular Tachycardia is rapid beating that originates in the heart's lower chambers and is often caused by heart disease. This serious condition can lead to sudden cardiac arrest and requires immediate treatment. Sinus Node Dysfunction is caused by damage to the heart's natural pacemaker, causing the heart to beat slowly and not increase correctly during exercise. Complete Atrioventricular (Heart) Block occurs when the electrical signal necessary for heart beat to occur does not move properly from the upper to lower chambers. Sinus Node Dysfunction and Heart Block are both treated with a pacemaker.

Continue Learning about Arrhythmia Symptoms

What types of abnormal slow heart rhythms develop in children?
Some abnormal heart rhythms, or arrhythmias, are fast, others are slow, and some are irregular. A nu...
More Answers
What does an arrhythmia feel like?
Chippenham Hospital - HCA VirginiaChippenham Hospital - HCA Virginia
Many rhythms, such as premature ventricular contractions (PVCs) and (PACs), can create a sensation o...
More Answers
What are the signs of arrhythmia?
Dr. Vivek Y. Reddy, MDDr. Vivek Y. Reddy, MD
Occasionally people experience palpitations, or heightened awareness of their heartbeat. It is commo...
More Answers
What are the symptoms of a cardiac arrhythmia?
Dr. Linda J. Bogar, MDDr. Linda J. Bogar, MD
There are many different symptoms associated with cardiac arrhythmias or irregular heart rate.  Howe...
More Answers

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.