Dysrhythmia and arrhythmia are two terms medical professionals use to describe when the heart does not beat in a typical rhythm. Although there is a slight linguistic difference in the meanings of the two words, they both refer to an uncharacteristic heart rate or rhythm.

Dysrhythmia and arrhythmia refer to when the heart does not beat at a regular rhythm or speed. This can occur due to changes to the electrical signals that control the heart or changes to the tissues in the heart.

The following article discusses the use of these two terms, what types of atypical heart rates are common, and treatment options.

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Dysrhythmia and arrhythmia refer to the same issue: when the heart is not beating at a regular rhythm or speed.

The terms dysrhythmia and arrhythmia differ mainly in a linguistic sense. “Dys” is a Greek prefix that means bad, ill, hard, or difficult. “A” is another Greek prefix that generally means not or without.

Therefore, dysrhythmia essentially means “bad rhythm,” and arrhythmia basically means “without rhythm.”

Since they generally refer to the same issue, doctors and researchers typically use the words interchangeably.

An atypical heart rate or rhythm occurs when the heartbeat does not fall within the standard range of beats per minute (BPM). The rate can be faster or slower than the average resting heart rate of around 50–100 BPM.

According to a research overview, the type of dysrhythmia and arrhythmia a person has can depend on different aspects, including:

  • Site of origin: Refers to where the abnormality is occurring, such as in the supraventricular, ventricular, or atrial chambers.
  • Rate of disturbance: Doctors may describe this as tachycardia or bradycardia.
  • Electrocardiogram appearance: Refers to how the heart rate appears on tests.
  • Mechanism of disturbance: The underlying cause of the atypical rate.

This condition can be either acute or chronic. In some cases, it can also be fatal, such as in the case of ventricular arrhythmias.

People living with arrhythmias may experience a wide range of symptoms. They also may not feel anything at all.

According to the American Heart Association (AHA), arrhythmias can feel like a fluttering sensation or a single skipped beat according to the type. If the arrhythmia starts to affect how well the heart works, it can lead to serious symptoms, such as:

If a person experiences chest pain or pressure, they should call 911 or go to their nearest emergency room since it could signal a heart attack.

In extreme circumstances, individuals may also experience collapse and sudden cardiac arrest.

Learn to tell whether chest pain is serious and when to contact a doctor.

The main cause of heart arrhythmia involves changes to the electrical signals that control the heart or changes to the tissues in the heart.

According to the National Heart, Lung, and Blood Institute, damage from illness, genetics, or injury is the most common direct cause. Some factors that can cause the condition include:

  • changes to the heart’s anatomy
  • return of blood flow following a heart attack
  • stress, anger, pain, or other events can cause the heart to beat irregularly
  • certain medications, such as those for high blood pressure, depression, or over-the-counter cold and allergy medications
  • disruption of electrical signals to the heart
  • deficiencies or excessive amount of electrolytes, hormones, or fluids in the blood

Several types of arrhythmia may affect a person’s heart. According to the National Heart, Lung, and Blood Institute, the four most common types include the below.

Bradyarrhythmia

Bradyarrhythmia, or bradycardia, occurs when the heartbeat is slower than average. The exact definition for this can vary between rates lower than 60 BPM and those lower than 50 BPM.

In some cases, a person in good physical condition may have a naturally lower resting heart rate. In these cases, their doctor may determine that an otherwise low heart rate may be typical for them.

Premature or extra beats

When an individual has a premature heartbeat or extra beats, it can feel like the heart skips a beat because the signal to beat comes sooner than normal.

If it occurs, it can cause what feels like a brief pause, after which there is a stronger than normal beat.

Learn about ectopic heartbeats, when the heart skips a beat.

Supraventricular arrhythmias

The National Heart, Lung, and Blood Institute defines these as arrhythmias that start in the upper chamber of the heart or in the pathway to the lower chambers. In many cases, these types of irregularities cause the heart to beat above 100 BPM when at rest. Doctors refer to this as tachycardia.

There are several potential subtypes, including:

  • Atrial flutter: This type of arrhythmia can cause the heart to beat around 250–350 BPM, with the upper chambers beating more frequently than the lower chambers.
  • Paroxysmal supraventricular tachycardia: This type of arrhythmia occurs most often in younger, healthier people during exercise and causes extra heartbeats as the signal travels from the upper to the lower chambers.
  • Atrial fibrillation: The most common subtype, it can cause the heart to beat around 400 BPM.

Learn more about supraventricular arrhythmias.

Ventricular arrhythmia

Ventricular arrhythmias begin in the ventricles, which are the lower chambers of the heart. They can be life threatening.

Subtypes of ventricular arrhythmia include:

  • Ventricular tachycardia: Involves a fast, regular heartbeat of more than 100 BPM. It may last for a few seconds or go on for a longer period of time.
  • Ventricular fibrillation: This ventricular arrhythmia causes the ventricles to quiver. This means the heart cannot pump blood properly, leading to a lack of oxygen in the brain and body.
  • Torsades de pointes: Causes a rapid heartbeat, which restricts oxygen-rich blood flow. It can develop in people with long QT syndrome — an inherited heart problem that affects how the heart beats — and may cause fainting.

A person should call 911 if they experience a tightening or pressure on their chest. This could be a sign of a heart attack that needs immediate attention.

An individual needs to speak with their doctor if they experience symptoms that may indicate an irregular heartbeat. A healthcare professional may help diagnose and treat the issue.

In some cases, a doctor may recommend starting or changing medication.

There are several tests a doctor may use to determine if a person has arrhythmia. Some common tests include:

  • Holter monitors: These devices can record the heart’s rhythms continuously for up to several days and provide a picture of what is going on throughout the day.
  • Event monitors: These devices record the heart’s signaling but only register information during an abnormal event rather than recording continuously.
  • Loop recorders: Similar to a Holter or event monitor, loop recorders register data over a longer period of time, from months to years.
  • Stress test: Involves a person using a treadmill or other cardio machine, while doctors monitor them to see if exercise triggers the arrhythmia.
  • Transtelephonic monitor: An individual may wear this device for a long period of time. Doctors often use it to diagnose intermittent or infrequent changes in heartbeats over a few weeks or months.
  • Tilt-table test: This test uses an adjustable table to simulate changing positions to check for faintness related to sudden changes from laying to standing or sitting to standing.
  • Electrophysiologic testing: This procedure involves inserting catheters into the heart to check for irregular rhythms.
  • Echocardiogram: This test uses soundwaves to get a picture of the heart to determine what may be causing the arrhythmia.
  • Esophageal electrophysiologic procedure: This test involves threading a sensor through the nose to position it near the heart, which provides a more accurate result than a typical EKG.

According to the AHA, doctors often consider arrhythmias harmless, so they may not recommend any treatment. After advising treatment, their goal typically involves the following aspects:

  • controlling heart rate
  • preventing clots
  • restoring normal rhythm
  • reducing other risk factors for heart disease or stroke
  • treating any underlying condition that may be the cause of the abnormal rhythm

In addition to formal treatment, a person can take steps to help manage and prevent arrhythmia. These steps include:

  • monitoring their pulse at home
  • taking all medications as prescribed and only stop after speaking to a doctor
  • avoiding foods or drinks that may trigger heart rate changes, such as tobacco, alcohol, or caffeine
  • using cold and allergy medications with caution
  • eating a nutritious diet
  • maintaining a moderate weight
  • exercising regularly
  • reducing high blood pressure
  • lowering cholesterol

Dysrhythmia and arrhythmia are two words doctors use to describe changes in heart rate and rhythm. The condition can cause the heart to beat too fast or too slow.

In some cases, a person may not experience any symptoms, while others may notice symptoms such as fatigue or faintness. In most cases, a doctor will not likely treat the arrhythmia unless an underlying condition could be causing it.

An individual can make behavioral changes to help control their heart rate, including getting regular exercise and eating a nutritious diet.