Supraventricular arrhythmia: causes, symptoms, outlook

A supraventricular arrhythmia is an irregular heart rate that begins above the ventricles, which are the two lower chambers of the heart. Most, but not all, supraventricular arrhythmias start in the atria, the upper chambers of the heart. They can cause the heart to beat too fast, too slow or irregularly.

This article explains what supraventricular arrhythmia is and lists different types. It will also provide information on the causes, outlook, and treatment options for the condition.

Electrical signals in the heart help control a person’s heart rate. Problems with the cells that trigger these electrical signals can lead to an irregular heart rate. People with supraventricular arrhythmias may have:

The heart contains four separate chambers: two atria and two ventricles. Irregular heart rates can start in any of the four chambers or in the areas surrounding those chambers. Supraventricular arrhythmias start above the ventricles, usually in the atria.

Most types of supraventricular arrhythmias make the heart beat too fast. Doctors call it supraventricular tachycardia.

Learn more about sinus arrhythmias, which begin in the upper right chamber of the heart, here.

Certain types of supraventricular arrhythmias include:

  • Atrial flutter: It happens when electrical signals in the atria make the heart beat fast or irregularly. A person may feel that their heart is beating too fast or adding extra beats.
  • Atrial fibrillation: Doctors classify atrial fibrillation as a type of supraventricular arrhythmia. It’s the most common cardiac arrhythmia in the United States. It happens when the atria are beating faster than usual due to dysfunctional electrical signals. A person may experience periods of very irregular and rapid heart rate, up to 180 beats per minute.
  • Nodal reentrant atrioventricular tachycardia or Reentrant atrioventricular tachycardia: These are types of paroxysmal arrhythmia. Paroxysmal means it happens sometimes, not all of the time. Common in young people, it can cause dizziness, rapid heartbeat or shortness of breath. This arrhythmia occurs because an additional pathway in the atrioventricular node or an accessory pathway causes the heart to beat irregularly. One type of reentrant atrioventricular tachycardia is Wolff-Parkinson-White syndrome, which involved an additional electrical path between the upper and lower chambers of the heart.
  • Sinus tachycardia: Sinus tachycardia is usually not an arrhythmia, and can occur when a person is exercising or feeling anxious, causing their heart to beat very quickly. However, sometimes the heart sends signals to beat faster when there is no reason to. Doctors call it inappropriate sinus tachycardia. Most people have symptoms similar to those they experience during intense exercise, including shortness of breath and rapid heart rate.

Ventricular arrhythmias, which are different, are arrhythmias that start in the ventricles, the two lower chambers of the heart.

Unlike supraventricular arrhythmias, ventricular arrhythmias are more likely to cause serious damage because they can reduce the flow of oxygen-rich blood through the heart and they are more unstable. People with ventricular arrhythmias have a higher risk sudden cardiac death.

The most common types of ventricular arrhythmias include:

  • Premature ventricular contraction (PVC): This is a milder arrhythmia than some others. It happens when the ventricles contract too early. This is usually not harmful, but can be of concern if a person has other heart health problems or if there is too much PVC, which can weaken the function of the heart.
  • Ventricular fibrillation: It is the most dangerous ventricular arrhythmia. It causes several electrical signals at a time to initiate irregular and chaotic contractions in the ventricles. This can lead to a very high heart rate of up to 300 beats per minute and can be fatal.
  • Ventricular tachycardia: This happens when the sinoatrial node fails to control the heart rate in the ventricles. This results in a rapid but potentially unstable heart rate. A person may feel dizzy or weak.

Heart rhythm irregularities occur when irregular electrical impulses change the way the heart beats. Many different conditions can cause these irregularities. Some include:

  • Medical conditions: A wide range of conditions, especially those that affect the endocrine system, can cause heart rate problems. A person can suffer from supraventricular arrhythmia due to conditions such as:
  • Some drugs: Any medicine that changes the body’s adrenaline system can cause irregular heartbeat. These include medications for conditions such as attention deficit hyperactivity disorder (ADHD). It can also include toxins, such as alcohol or cocaine.
  • Structural or congenital problems: Some people can be born with heart problems. For example, atrioventricular (nodal) reentrant tachycardia occurs when an additional “open” electrical pathway occurs in the heart. Conduction through this pathway can be present from birth.
  • Heart surgery: Surgery in the upper chambers of the heart can cause supraventricular tachycardia. For example, if a person has surgery for a congenital heart defect, they may notice an irregular heartbeat.

A wide range of behavioral factors can trigger irregular heartbeats in people who are sensitive to them. These may include:

Learn the potential causes of skipping heart here.

The most common symptom of an arrhythmia is a feeling that the heart is beating too fast, too slowly, or that it is skipping or adding beats. This is true for all arrhythmias, so a person cannot determine which type they have based on symptoms alone.

Certain other symptoms that a person might notice include:

In many cases, a doctor can diagnose a cardiac arrhythmia using a electrocardiogram (ECG). It is a machine that measures heart rhythms. The test is painless and involves electrodes that doctors place on the skin.

In some people, the diagnosis is more difficult because they only suffer from periodic cardiac arrhythmias. In this case, a portable heart monitor, called a Holter monitor, can detect irregular heartbeats. A doctor may send a person home to wear the device for a day or even weeks, depending on their symptoms.

A doctor will also ask about a person’s medical history, medication and drug use, and other symptoms. Blood tests can help rule out other conditions.

The right treatment depends on several factors, including whether the cardiac arrhythmia is dangerous or bothersome, a person’s general health, and how often a person experiences the arrhythmia. Some treatment options include:

  • Medication: Certain medications, such as beta blockers, calcium channel blockers, and adenosine, can help regulate heart rate in some people.
  • Valsalva maneuver: This can stop a rapid heart rate in some people. Simply hold your nose closed, then blow your nose for 15 seconds. Ask a doctor if this is a safe home option for managing arrhythmias.
  • Cold water: People with a sudden rapid heartbeat may find that putting cold water on their face slows their heart rate.
  • Behavior changes: Some people can reduce the frequency of arrhythmias by making lifestyle changes, such as avoiding stimulants like caffeine. Exercising and eating a heart-healthy diet can also lower a person’s risk of heart disease and help prevent certain risk factors for arrhythmias, such as high blood pressure.
  • Ablation: If the medication does not work and a person’s arrhythmia is dangerous, a doctor may recommend catheter ablation. This procedure removes or scars damaged or dysfunctional tissue that causes irregular electrical signals in the heart.

Learn how to eat heart healthy eating here.

Heart arrhythmias can be very frightening, especially for people who don’t know why their hearts are beating fast. Getting a diagnosis is important because some supraventricular tachycardias are harmless and can all be treated.

A person should not self-diagnose at home based on their symptoms or assume that they do not need treatment. People should contact their doctor if they have any concerns.

About Terry Gongora

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