Bigeminy is the alternation between a regular heartbeat and extra, skipped heartbeat. People may experience bigeminy as heart palpitations or fluttering. They may describe the sensation as the heart skipping a beat.

Many people will experience bigeminy at some point in their lives, and it is not usually a cause for concern.

However, severe or frequent bigeminy may indicate an underlying medical issue that requires treatment. Learning more about bigeminy can help people understand their symptoms and know when to seek medical care.

This article outlines the causes and symptoms of bigeminy and the two different types of bigeminy a person may experience. We also provide information on diagnosing and treating bigeminy and when to see a doctor.

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Medical experts may not always be able to determine the cause of bigeminy. However, this condition and changes in the heart’s rhythm are linked. These changes are due to variations in the heart’s electrical system.

Each beat of the heart is triggered by an electrical impulse, causing a rhythmic cycle of contraction and relaxation that pumps blood through the heart’s four chambers.

The characteristic sound of the heartbeat comes from the valves between the chambers opening and closing as blood circulates through the heart. When the timing gets skewed, the rhythm gets skewed. The technical term for this is arrhythmia. There are many forms of arrhythmia, including bigeminy.

People may experience bigeminy as heart palpitations. However, not all sensations of palpitations are due to arrhythmia. A 2013 study of people treated for palpitations at a university medical center found the following causes of palpitations:

  • 40% were caused by arrhythmia
  • 31% were due to anxiety or panic disorders
  • 16% had no identifiable cause
  • 6% were due to prescription, over-the-counter (OTC), or illegal drugs
  • 4% had non-cardiac causes
  • 3% had a cardiac cause other than arrhythmia

Bigeminy happens when a regular heartbeat is interrupted by a skipped, or extra, heartbeat known as a premature ventricular contraction (PVC). The heartbeat then returns to its usual rhythm.

When bigeminy happens, a person may feel as if their heart is skipping beats. This perceived pause is due to the second heartbeat occurring too quickly after the first, leading to a compensatory pause to “reset” the electrical system. These unusual, premature beats are also called premature contractions.

Bigeminy is not usually a cause for concern. However, a person should seek prompt medical attention if any of the following symptoms accompany their palpitations:

The heart consists of four chambers: two on the top, called atria, and two on the bottom, called ventricles.

Both the atria and ventricles have values that open and close in a synchronized way that helps to control blood flow throughout the body. This is why a pause and then another heartbeat follow each heartbeat.

Bigeminy can occur as a result of a heartbeat irregularity involving either the atrium or ventricles. Bigeminy involving a heartbeat irregularity in the atrium is due to premature atrial contractions (PACs), while bigeminy involving the ventricles is due to premature ventricular contractions (PVCs).

PACs

PACs are premature heartbeats that occur in the heart’s upper chambers, or “atria.”

Not everyone who has PACs will experience symptoms. Many people only discover that they have the condition during a routine medical check.

People who do experience PAC symptoms report feelings of a skipped heartbeat or a premature heartbeat. Most report feeling these symptoms more frequently at night.

PVCs

PVCs are irregular heartbeats in the heart’s lower chambers, or “ventricles.”

Under normal conditions, a group of cells called the “sinoatrial node” innervates the heart and controls the heartbeat. Some cases of PVC occur when a group of fibers called the Purkinje fibers supply nerves to the heart instead of the sinoatrial node.

People with PVC report feeling a fluttering or a flip-flop feeling in their chest. The following are often causes of premature ventricular contractions:

A person who experiences heart palpitations should see a doctor to get evaluated, especially if they have any of the following:

  • severe or frequent heart palpitations
  • a personal history of heart disease
  • a family history of heart disease

Symptoms and medical history

When diagnosing bigeminy or other types of heart arrhythmia, a doctor will ask the person about their symptoms. They may also ask about factors that can affect heart health, such as:

  • heart issues, such as high blood pressure or previous arrhythmia
  • thyroid problems
  • diabetes
  • personal stress levels
  • exercise habits
  • caffeine and alcohol consumption
  • tobacco use
  • use of cocaine and other illegal drugs
  • prescription drug use
  • use of supplements or OTC drugs

If a person has a pre-existing heart condition, severe or frequent episodes of bigeminy could indicate an increased risk of serious heart issues.

Physical examination

A doctor will need to perform a physical exam and electrocardiogram (ECG) to diagnose bigeminy. This involves assessing the condition of the heart. The first steps for this process involve:

  • listening to the heart rate and rhythm
  • checking for a heart murmur
  • taking pulse and blood pressure readings
  • looking for signs of heart failure, such as edema or swelling
  • checking thyroid health, and other possible causes of arrhythmia

The best way to examine heart rhythm is with an ECG. An ECG measures and records the intensity and timing of the electrical impulses that stimulate the different heart chambers to contract and relax.

If the ECG does not catch these events, a doctor may suggest a person wear a Holter monitor or event monitor for a longer period of time. These devices monitor a person’s heartbeat.

Bigeminy sometimes resolves on its own or by making some lifestyle adjustments. In some cases, a person may require medical treatment.

Lifestyle adjustments

Medical experts have identified several substances that can trigger episodes of bigeminy. Limiting or avoiding these substances can make it easier for the heart to keep a steady beat.

Potential triggers to avoid include:

  • caffeine in coffee, tea, energy drinks, and some soft drinks
  • nicotine
  • alcohol
  • illegal drugs
  • medications for seasonal allergies, asthma, and colds

High blood pressure or sleep apnea may increase the likelihood of palpitations, which gives people with hypertension more reason to manage their blood pressure carefully.

Exercise may sometimes trigger episodes of bigeminy, so people who have had palpitations should use caution when starting or returning to fitness activities.

People may find they experience fewer PVCs during the exercise itself. However, they can occur afterward.

Medical treatments

If a person experiences severe or frequent episodes of bigeminy, their doctor may prescribe drugs called beta-blockers. These drugs slow the heart rate and reduce the irritability of the heart’s electrical system, which can help reduce arrhythmia symptoms.

In rare cases of bigeminy that require more aggressive treatment, a doctor may recommend a surgical procedure called catheter ablation. This process involves scarring heart tissue in a way that blocks abnormal electrical signals.

Bigeminy is a type of heart arrhythmia in which the heart beats once normally and once abnormally in quick succession, followed by a pause.

Bigeminy does not always cause symptoms. However, any person who experiences a sensation of a skipped heartbeat, or palpitations, should contact a doctor to determine what has caused this.

Some cases of bigeminy are transient and benign and do not require treatment.

However, a person who experiences severe or frequent episodes of bigeminy should see their doctor for a diagnosis. They may require a thorough heart examination and other medical tests to establish an underlying medical cause.

For people who already know they have heart disease, frequent episodes of bigeminy may signal an increased risk of serious heart problems. These people should talk with their doctor about changes to their current treatment plan.