Arrhythmia Overview

Reviewed: May 8, 2014

An arrhythmia is a disorder of the heart rate or heart rhythm. This includes beating too fast (tachycardia), beating too slow (bradycardia), or beating irregularly.

Although most arrthymias are harmless, some can be serious and even life threatening. Arrthymias may cause the heart to not be able to pump enough blood to the rest of the body. If this occurs, there could be damage to the heart, brain, and other organs.

The heart is normally able to pump blood out to the body without working too hard. It has an electrical system that ensures that it squeezes regularly. The impulse signaling the heart to squeeze starts in the sinoatrial node, a group of cells also known as the sinus node or SA node located in the upper right chamber. This impulse acts as a natural pacemaker.

The electrical impulse normally:

  • leaves the SA node and goes through the two upper chambers of the heart (atria). The atria then contracts, and blood is pumped into the two lower chambers of the heart (ventricles).
  • Then it goes through a different group of cells known as the antrioventricular node  (AV node). The AV node is between the ventricles and the atria. The signal slows and the ventricles finish filling with blood.
  • Lastly, it travels along a divided pathway, the left bundle branch and right bundle branch. The signal then goes from each pathway to the ventricles, and they pump blood to the rest of the body, including the lungs.

The electrical impulse uses different nerve messages to tell the heart to beat slower or faster. Problems occurring anywhere along this electrical system cause various arrhythmias.

Examples Include:

  • Atrial fibrillation or flutter
  • Atrioventricular nodal reentry tachycardia (AVNRT)
  • Heart block or atrioventricular block
  • Paroxysmal supraventricular tachycardia
  • Sick sinus syndrome
  • Wolff-Parkinson-White syndrome
  • Ventricular fibrillation

Alternative names for arrhythmia include:

  • Dysrhythmia
  • Abnormal heart rhythms
  • Bradycardia
  • Tachycardia


Arrhythmia Symptoms

Arrhythmias may be permanent or may come and go. It is possible to not feel any symptoms when the arrhythmia is present. Sometimes the symptoms are only noticed during physical activity.

The severity of symptoms varies from mild to severe, even life-threatening.

Common symptoms may be:

  • Palpitations - feelings that the heart skipped a beat, fluttering, or beating too hard/fast.
  • Pauses between heartbeats
  • Irregular heartbeat
  • Slow heartbeat

Serious symptoms include:

  • fainting
  • chest Pain
  • slow or fast heartbeat (palpitations)
  • dizziness or light-headedness
  • shortness of breath
  • sweating

Arrhythmia Causes

The risk of getting an arrhythmia varies depending on:

  • Blood chemistry imbalances, such as abnormal potassium levels
  • Cardiomyopathy a weakening of the heart muscle or a change in the heart muscle
  • Heart failure
  • Overactive thyroid gland
  • Heart attack
  • High blood pressure
  • Coronary heart disease
  • Rheumatic heart disease

Some substances or drugs may also cause arrhythmias:

  • Amphetamines
  • Smoking
  • Caffeine
  • Cocaine
  • Beta blockers
  • Psychotropics
  • Sympathomimetics
  • Anti-arrhythmic medications prescribed to treat one type of arrhythmia can sometimes cause another type of arrhythmia

Congenital heart defects can also cause some arrhythmias. "Congenital," means that the defect is present at birth. An example is Wolff-Parkinson-White syndrome.

The cause of an arrhythmia can also be unknown.

Arrhythmia Diagnosis

Sometimes arrhythmias are difficult to diagnose, and even more difficult when they only cause symptoms from time to time. Often times arrhythmias are diagnosed by specialized doctors such as cardiologists, pediatric cardiologists, or electrophysiologists.

Family History

A doctor will ask a patient about his or her family's medical history. In addition, they will ask about medications the patient is taking and their health habits. They may also ask about recent emotional stress or anger. The doctor will want to know whether you or anyone in your family has:

  • a history of heart disease
  • a history of high blood pressure
  • diabetes
  • thyroid problems
  • a history of arrhythmias
  • died suddenly
  • other illnesses or health problems


The doctor will perform a physical exam. This may include:

  • Listening to the patient's heart rate and rhythm
  • Listening for a heart murmur (an unusual sound)
  • Checking the patient's pulse for the heart rate
  • Looking for swelling in the patient's feet or legs. This could be a sign of heart failure or an enlarged heart
  • Checking for signs of other diseases that could be causing the problem

EKG (Electrocardiogram)

This is the most common test for arrhythmia. Simple and painless, an EKG records the heart's electrical activity. It shows the heart's rhythm and rate. The standard test records the heart for a few seconds and will not show any arrhythmias that don't happen during those few seconds.

The doctor may require the patient to wear a portable EKG monitor to diagnose arrhythmias that come and go. Commonly used portable EKG monitors are Holter monitors and event monitors. A Holter monitor is worn during normal daily activities and records the heart's electrical activity for either 24 hours or 48 hours. An event monitor is similar to the Holter monitor except it only records at certain times. There are other monitors, such as ones that you activate with a button when you start to feel symptoms.

Other Procedures and Tests

The doctor may use any of the following tests to help to confirm or eliminate their diagnosis:

  • Blood test
  • Chest X-Ray
  • Echocardiography
  • Stress Test
  • Electrophysiology study (EPS)
  • Tilt table testing
  • Coronary angiography
  • Implantable loop recorder

Living With Arrhythmia

Some people have mild arrhythmias and can live healthy lives without treatment. There are also people with serious arrhythmias who can live healthy lives after treatment.

Living with arrhythmia is different depending on several factors:

  • The kind of arrhythmia. Supraventricular tachycardia is less dangerous than ventricular tachycardia or ventricular fibrillation
  • The general pumping ability of the heart (ejection fraction)
  • The presence of heart disease and how well it can be treated

If diagnosed with an arrhythmia, one should:

  • Go to all medical appointments with a list of current medications they are taking.
  • Take medication as it is prescribed as well as check with a doctor before taking anything over-the-counter.
  • Tell the doctor if symptoms are getting worse or new symptoms have appeared.
  • Let the doctor know if side effects from the medication are being experienced.
  • If taking blood thinning medications, go to the doctor for regular checkups
  • Lie down if feeling dizzy, faint, or lightheaded. Do not try to drive or walk.
  • Ask a doctor about vagal maneuvers
  • Learn how to take one's own pulse.
  • Live a healthy lifestyle

Arrhythmia Treatments

The most common treatments for arrhythmia are medicines, medical procedures, and surgery. Treatment may be recommended if the arrhythmia is causing serious symptoms or if it is increasing the patient's risk for sudden cardiac arrest, stroke, heart failure, or other serious conditions.


There are medicines that can slow down a fast heart rate. There are also some that can cause a irregular heart beat to have a normal rhythm. Theses medicines are called antiarrhythmics.

Also used to treat atrial fibrillation,  medicines used to slow down a fast heart rate include:

  • Beta blockers, such as metoprolol and atenolol
  • Calcium channel blockers, such as diltiazem and verapamil
  • Digoxin or digitalis

Medicines used to regulate the heart's rhythm include:

  • Amiodarone
  • Sotalol
  • Flecainide
  • Propafenone
  • Dofetilide
  • Ibutilide
  • Quinidine
  • Procainamide
  • Disopyramide

Many of these medications may have side effects, and it is possible for some side effects to make an arrhythmia worse. There is not yet a medication that can speed up a heart rate; Slow heart rates are treated with pacemakers. Medication is also used to treat underlying medical conditions that cause arrythmias.

Medical Procedures

If an arrhythmia is serious, urgent treatment is needed to restore a normal rhythm. These treatments include:

  • Electrical "shock" therapy (cardioversion or defibrillation). This is an electric jolt to the heart.
  • Implantation of a temporary pacemaker to interrupt the arrhythmia. This is a small device that is placed under the skin on the chest. They have sensors that detect the electrical signals in the heart and send out electrical pulses to help the heart beat normally.
  • Implantable cardioverter defibrillator (ICD). Patients who have a risk for ventricular fibrillation are sometimes treated with this device. It is similar to a pacemaker in that it is placed under the skin on the chest and also uses electrical pulses. However, this device monitors the heartbeat continuously and sends out an electric shock to the heart when a serious ventricular arrhythmia is detected.
  • Catheter ablation. This is a medicine delivered through a vein in the patient's arm, upper thigh, or neck through to the patients heart. This medicine eliminates small parts of the heart tissue where the irregular heart rhythms might be starting. This procedure is normally done in a hospital as part of a electrophysiology study.


Some arrhythmias might be treated with surgery. If surgery is going to be performed for another reason, such as repairing a heart valve, then the doctor might also treat the arrhythmia.

Maze surgery is one type of surgery used to treat arrhythmias. In this procedure, a surgeon will make small cuts or burns in the patient's atria. These will help keep the disorganized electrical impulses from spreading.

If the patient has coronary heart disease that is causing an arrhythmia, a procedure called coronary artery bypass grafting may be recommended. This procedure is used to help blood flow to the heart muscle.


Other treatments that might be used to treat arrhythmias are called Vagal maneuvers. Sometimes these simple exercises are able to help stop or slow certain types of arrhythmias. The exercises affect the vagus nerve - a nerve that helps control the heart rate. These exercises are not the best treatment for everyone. A doctor may suggest them as am option if they are appropriate.

Some of these exercises are:

  • Coughing or gagging
  • Valsalva maneuver. This involves holding one's breath and bearing down.
  • Immersion of the face in ice-cold water
  • Putting one's fingers on their eyelids and gently pressing down

Arrhythmia Other Treatments

By taking action to prevent coronary heart disease, you can reduce your chance of developing an arrhythmia.

Such as:

  • Eating a well-balanced, low-fat diet
  • Exercising regularly
  • Not Smoking

Contact a medical professional if:

  • you develop any of the symptoms of a possible arrhythmia
  • you have been diagnosed with an arrhythmia and your symptoms worsen or do not improve with treatment

Helpful organizations include:

  • American Heart Association
  • Heart Rhythm Society