Published : May 28, 2023

Arrhythmia – Focusing SVT

An arrhythmia is an irregular heartbeat. If you have an arrhythmia, your heart may beat faster or slower than others without arrhythmia. There are several different conditions might cause your heart to beat abnormally, and treatment depends on the cause.


What is an arrhythmia?

An arrhythmia (also called dysrhythmia) is an irregular or abnormal heartbeat.


What are the types of arrhythmias?

Supraventricular arrhythmias: Arrhythmias that begin in the atria (the heart’s upper chambers). “Supra” means above. “Ventricular” refers to the lower chambers of the heart or ventricles.

Ventricular arrhythmias: Arrhythmias that begin in the ventricles (the heart’s lower chambers).

Bradyarrhythmias: Slow heart rhythms that may be caused by disease in the heart’s conduction system, such as the sinoatrial (SA) node, atrioventricular (AV) node or HIS-Purkinje network.


What are the types of supraventricular arrhythmias?

Supraventricular arrhythmias begin in the atria or the upper chambers of your heart. Types of supraventricular arrhythmias include:

Paroxysmal supraventricular tachycardia (PSVT): A rapid but regular heart rhythm that comes from the atria. This type of arrhythmia begins and ends suddenly.

Accessory pathway tachycardias (bypass tract tachycardias): A fast heart rhythm caused by an extra, abnormal electrical pathway or connection between the atria and ventricles. The impulses travel through the extra pathways as well as the usual route. This allows the impulses to travel around your heart very quickly, causing it to beat unusually fast (example: Wolff- Parkinson-White syndrome).

AV nodal re-entrant tachycardia (AVNRT): A fast heart rhythm caused by the presence of more than one pathway through the atrioventricular (AV) node.

Atrial fibrillation: A very common irregular heart rhythm. This happens when many impulses begin and spread through the atria, competing for a chance to travel through the AV node. This results in a disorganized rapid and irregular rhythm. Because the impulses are traveling through the atria in a disorderly fashion, there’s a loss of coordinated atrial contraction.


What are the symptoms of an arrhythmia?

An arrhythmia may be “silent” and not cause any symptoms. A doctor can find an irregular heartbeat during an examination by taking your pulse, listening to your heart or performing diagnostic tests.


What causes arrhythmias?

Arrhythmias can be caused by:

  • Coronary artery disease.
  • Irritable tissue in the heart (due to genetic or acquired causes).
  • High blood pressure.
  • Changes in the heart muscle (cardiomyopathy).
  • Valve disorders.
  • Electrolyte imbalances in your blood, such as sodium or potassium imbalances.
  • Injury from a heart attack.
  • The healing process after heart surgery.
  • Other medical conditions.


How is an arrhythmia diagnosed?

If you have symptoms of an arrhythmia, you should make an appointment with a cardiologist. You may want to see an electrophysiologist — a cardiologist who has additional specialized training in the diagnosis and treatment of heart rhythm disorders. After assessing your symptoms and performing a physical examination, the cardiologist may perform a variety of diagnostic tests to help confirm the presence of an arrhythmia and indicate its causes. Some tests that may be done to confirm the presence of an irregular heart rhythm include:

  • Electrocardiogram (ECG): A picture of the electrical impulses traveling through the heart muscle. An ECG is recorded on graph paper, through the use of electrodes (small, sticky patches) that are attached to your skin on the chest, arms and legs.
  • Ambulatory monitors, such as the Holter monitor.
  • Stress test: A test used to record arrhythmias that start or are worsened with exercise. This test also may be helpful to determine if there is underlying heart disease or coronary artery disease associated with an arrhythmia.
  • Echocardiogram: A type of ultrasound used to provide a view of the heart to determine if there is heart muscle or valve disease that may be causing an arrhythmia. This test may be performed at rest or with activity.

Electrophysiology study (EPS): A special heart catheterization that evaluates your heart’s electrical system. Catheters are inserted into your heart to record the electrical activity. The EPS is used to find the cause of the abnormal rhythm and determine the best treatment for you. During the test, the arrhythmia can be safely reproduced and terminated.