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Arrhythmias

Definition

The heart normally works in a regular, steady pattern. Arrhythmias are unexpected disruptions in the patterns. Arrhythmias may be:

  • Very slow heart rate—bradycardia
  • Very fast heart rate—tachycardia
  • Irregular rhythm
  • Skipped contractions (beats) of the heart

Arrhythmias may be short bursts of abnormal rhythms or last longer. Most will not affect overall health but some arrythmias can slow the flow of blood to the body or increase the risk of other medical conditions such as stroke.

Causes    TOP

The contraction of the heart is controlled by an electrical impulse. The impulse starts in a group of cells called the sinoatrial (SA) node and moves from the top to the bottom of the heart. The heart will contract first in the upper areas of the heart called the atria and then the lower areas of the heart called the ventricles. Arrhythmias may occur if:

  • The sinus node is damaged and can not send normal electrical impulses
  • The electrical impulse can not travel smoothly through the heart
  • Other influences like hormones or drugs stimulate the SA node
  • Other areas of the heart stimulate a contraction that does not match the pattern of the SA node

Conduction Pathways of the Heart

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Risk Factors    TOP

Factors that may increase your risk of arrhythmias include:

Symptoms    TOP

Not all arrhythmias will cause symptoms. Some arrhythmias may be felt as a fluttering in the chest, skipped heartbeat, or fast heartbeat.

Arrhythmias that slow the flow of blood through the heart will also decrease the flow of blood to the body. If the flow is slowed enough it can lead to:

  • Fainting
  • Lightheadedness
  • Weakness
  • Fatigue
  • Shortness of breath
  • Chest pain

Diagnosis    TOP

The doctor will ask about your symptoms, medical history, and family history. A physical exam will be done including listening to your heart, taking your pulse, and looking for any signs of heart problems.

The electrical activity of the heart and any abnormal activity can be found with one of the following:

  • Electrocardiogram (EKG)—electrodes placed on the skin record the heart's activity for a period of time.
  • Holter monitor—an EKG device that records rhythm over 24-48 hours. It can help find arrythmias that randomly occur.
  • Exercise stress test—an EKG that is taken while you perform a physical activity. It can help find arrhythmias that may be only associated with physical stress.
  • Electrophysiological study—an invasive procedure that is used for serious arrhythmias.

To help find potential causes or to look for structural problems of the heart the doctor may order:

  • Blood tests and urine tests—to look for abnormal levels of substances in the blood that may stimulate arrhythmias
  • Imaging tests may include:

Treatment    TOP

Not all arrhythmias need to be treated. Many are harmless and do not cause problems. When arrhythmias cause symptoms serious enough to affect your daily life or increase the risk of other conditions, treatment may be needed. The goal of arrhythmia treatment is to restore your heart to a normal rhythm. The type of treatment will depend on your specific arrhythmia and your overall health. Options include:

  • Medications—can be used to slow down or speed up your heart rate or correct imbalances that are causing an arrhythmia.
  • Cardioversion—certain rhythms can be shocked back into a normal rhythm. An electrical pulse is delivered through paddles to reset the electrical pattern of the heart.
  • Medical device implantation—a device may be implanted to track the heart's function and send an electrical impulse to correct the rhythm when needed. Options include:
  • Other surgical options—destruction or scarring of certain areas of the heart tissue will control the flow of electrical impulses to help decrease arrhythmias. The destroyed or scarred tissue will also stop irregular impulses from traveling through the heart. Options include:
    • Ablation—An area of the heart that is responsible for an abnormal rhythm may be surgically removed or altered (ablated) with different techniques.
    • Maze procedure and mini-maze procedure—The Maze procedure creates a pattern of scar tissue in the upper chambers of the heart. This makes a pathway for electrical impulses to travel through the heart. It also blocks the pathway for fast or irregular impulses.

Prevention    TOP

Not all arrhythmias can be prevented. To help reduce your chance of certain arrhythmias:

  • Treat underlying conditions that might lead to arrhythmias.
  • Avoid substances that trigger arrhythmia or make it worse, such as caffeine, alcohol, tobacco, and certain medications.
  • Follow general advice to prevent heart disease:
    • Maintain a healthy weight.
    • Talk to your doctor about a safe exercise program.
    • Do not smoke. If you smoke, find out ways you can quit.
    • Eat a healthful diet that is low in saturated fat and rich in whole grains, fruits, and vegetables.

RESOURCES:

American Heart Association
http://www.heart.org/
Heart Rhythm Society
http://www.hrsonline.org/

CANADIAN RESOURCES:

Canadian Cardiovascular Society
http://www.ccs.ca/
Heart and Stroke Foundation
http://www.heartandstroke.com

References:

Arrhythmias. American Heart Association website. Available at:
...(Click grey area to select URL)
Accessed November 8, 2012.
Arrhythmia. Texas Heart Institute website. Available at:
...(Click grey area to select URL)
Updated October 2012. Accessed November 8, 2012.
Atrial fibrillation. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115288/Atrial-fibrillation. Updated September 27, 2016. Accessed September 29, 2016.
Explore arrhythmia. National Heart Lung and Blood website. Available at:
...(Click grey area to select URL)
Updated July 1, 2011. Accessed November 8, 2012.
Sick sinus syndrome. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T113692/Sick-sinus-syndrome. Updated December 8, 2015. Accessed September 29, 2016.
Ventricular arrhythmias. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated September 27, 2016. Accessed June 28, 2016.
Last reviewed December 2016 by Michael J. Fucci, DO
Last Updated: 12/20/2014