What is an arrhythmia?
An arrhythmia is an abnormal heart rhythm.
Some arrhythmias can cause problems with contractions of the heart chambers by:
- Not allowing the ventricles (lower chambers) to fill with an adequate amount of blood because an abnormal electrical signal is causing the heart to pump too fast or too slow.
- Not allowing a sufficient amount of blood to be pumped out to the body because an abnormal electrical signal is causing the heart to pump too slowly or too irregularly.
- Not allowing the top chambers to work properly.
In any of these situations, the body’s vital organs may not receive enough blood to meet their needs.
Cardiac Arrhythmia Video Overview »
What are the symptoms of arrhythmias?
The effects on the body are often the same, however, whether the heartbeat is too fast, too slow, or too irregular. Some symptoms of arrhythmias include, but are not limited to:
- Palpitations (a sensation of fluttering or irregularity of the heartbeat)
- Weakness
- Fatigue
- Low blood pressure
- Dizziness
- Fainting
- Heart failure
- Collapse and cardiac arrest
- Difficulty feeding (in babies)
- The symptoms of arrhythmias may resemble other conditions. Consult your doctor for a diagnosis.
To better understand arrhythmias, is it helpful to understand the heart’s electrical conduction system.
The heart’s electrical system
The heart is, in the simplest terms, a pump made up of muscle tissue. The heart’s pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart.
How are arrhythmias diagnosed?
The electrical activity of the heart is measured by an electrocardiogram (ECG or EKG). By placing electrodes at specific locations on the body (chest, arms, and legs), a graphic representation, or tracing, of the electrical activity can be obtained. Changes in an ECG from the normal tracing can indicate arrhythmias, as well as other heart-related conditions.
What are the different types of arrhythmias?
A condition in which the electrical signals come from the atria at a very fast and erratic rate. The ventricles contract in an irregular manner because of the erratic signals coming from the atria A condition in which the electrical signals come from the atria at a very fast and erratic rate. The ventricles contract in an irregular manner because of the erratic signals coming from the atria that activate the AV node. Learn More »
A potentially life-threatening condition in which an electrical signal is sent from the ventricles at a very fast, but often regular rate. If the heart rate is sustained at a high rate for more than 30 seconds, symptoms, such as weakness, fatigue, dizziness, fainting, or palpitations, may be experienced. Cardiac arrest may occur. A person in VT may require an electric shock or medications to convert the rhythm back to normal sinus rhythm. Learn More »
- Supraventricular Tachycardia (SVT)
A condition in which the heart rate speeds up due to abnormal tissue above the ventricles. There are several different forms of SVT arrhythmias. A couple of the more common examples include arrhythmias caused by an abnormal electrical connection between the top and bottom chambers of the heart, such as atrioventricular node reentry tachycardia also referred to as paroxysmal SVT, or atrioventricular reentry tachycardia due to an extra conduction pathway between the atria and the ventricles. If that pathway conducts signals from the atria to the ventricles, it is known as Wolff-Parkinson-White Syndrome. Another common SVT form can be caused by a site in the atria that fires rapidly called atrial tachycardia. SVT usually begins and ends rapidly, occurring in repeated periods. These arrhythmias can cause symptoms, such as weakness, fatigue, dizziness, fainting, or palpitations if the heart rate becomes too fast. They can cause shortness of breath or chest discomfort.