Electrophysiology (EP) procedures are crucial in diagnosing and treating various heart rhythm disorders. They involve a doctor placing thin catheters into the heart to assess its electrical activity.

The catheters have electrodes at their tips, which measure the heart’s electrical signals. This mapping allows cardiologists to pinpoint the origin of an abnormal heart rhythm.

The heart’s electrical activity regulates the contraction of the heart muscle, allowing it to pump blood effectively throughout the body, delivering oxygen and nutrients. Problems with the heart’s rhythm, which are known as arrhythmias, can lead to a range of symptoms.

This article explores EP procedures, their uses, what to expect, and potential side effects.

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An EP procedure is a medical test that evaluates heart rhythm. A doctor who specializes in heart rhythms, or an electrophysiologic (a type of cardiologist), will typically perform the procedure.

During an EP study, the cardiologist will insert thin, flexible wires known as catheters into specific locations within the heart. These catheters have electrodes at their tips, which can measure the heart’s electrical signals and help create detailed maps of the heart’s electrical activity.

This mapping allows the cardiologist to pinpoint where heart rhythm problems originate and identify areas that require attention. In some cases, a cardiologist may also carry out treatments during the procedure, such as ablation.

Doctors use EP to help diagnose and treat various heart rhythm problems. A doctor may recommend an EP test if there is evidence a person has arrhythmia. The symptoms of arrhythmia can include:

  • dizziness
  • fainting
  • heart palpitations
  • weakness

They may try an electrocardiogram (EKG) first. This is a noninvasive test that involves placing electrodes on the chest to assess the heart’s electrical activity. Alternatively, they may order an event monitor. An EKG records the heart for several seconds, while an event monitor records heart activity for several days or weeks.

Depending on the findings of these tests, a doctor may then order an EP study to help evaluate and map arrhythmias, such as:

  • atrial fibrillation, which is an irregular rhythm in the upper chambers of the heart
  • ventricular fibrillation, which is an irregular rhythm in the lower chambers of the heart
  • bradycardia, which is a slow heart rate
  • tachycardia, which is a fast heart rate
  • conduction disorder, which involves problems with the electrical signals going through the heart

EP studies can include several different tests in one procedure. The tests a doctor includes will depend on the person’s symptoms and what they are trying to find out.

The procedure may include:

  • Cardiac mapping: This test helps determine any places in the heart that require ablation, or the destruction of dysfunctional cells. Destroying these cells may help regulate heart rhythm.
  • Pacing of the atria and ventricles: This involves sending electrical signals through the catheters to make the heart beat slower or faster, which can help with finding the source of an arrhythmia.
  • Arrhythmia induction: The doctor may use medications to induce an abnormal heart rhythm. This may help them pinpoint where the arrhythmia is coming from.
  • Intracardiac electrogram: This test measures how electrical impulses travel through the heart.

Here is what to expect before and during an EP procedure.

What happens before the EP study?

Running up to the EP study, a person may need to take steps to prepare. This could include blood tests, an EKG, or discussing the medications they take with a doctor. These could affect the test, depending on what they are.

If a person does take drugs that could interfere, a doctor may create a plan for them to stop taking the medication temporarily, or switch them to an alternative, before the EP procedure. A person may also need to avoid eating or drinking for 6–8 hours before the test, according to the American Heart Association (AHA).

Usually, doctors perform EP studies at a cardiac catheterization laboratory. It is typically an outpatient procedure, meaning a person does not need to stay in the hospital. However, they should arrange for someone to pick them up after their appointment.

What happens during the EP study?

Before the procedure begins, a medical professional will insert an IV line into a person’s arm to administer relaxing medication known as a sedative.

Next, they will shave the area where the doctor will insert the catheters. This is usually the groin but can be the arm or neck. A medical professional will administer local anesthetic to numb the area.

Next, the cardiologist will insert a thin tube, or sheath, into the artery or vein they are using. They will then guide the catheters through the sheath into the blood vessels and to the heart. A video screen will display the position of the catheters, aiding the doctor in their placement.

The person may feel pressure at the insertion site, but no significant pain. If they do experience any pain, they should tell the doctor.

Once the cardiologist has the catheters in place, they will send small electric pulses to stimulate the heart and make it beat at different speeds. The individual may notice their heart beating stronger or faster during this process.

The EP catheters will pick up the heart’s electrical signals, allowing the doctor to record and analyze them.

After the EP study, the doctor will remove the catheters and apply pressure to the insertion site. A nurse may then dress the wound with gauze or bandage, and monitor the person’s vital signs and heart rhythm.

The person must stay lying in bed for a while before they sit up. They can then move and walk around once a doctor approves this.

A person can often return to their usual activities the day after their procedure, but they should not drive for at least 24 hours, according to the AHA. The insertion site may be sore for a few days and may have a small bruise.

An EP study usually takes between 1–4 hours, according to the AHA. The time can vary depending on the complexity of the person’s condition and the specific tests and interventions a doctor performs or orders.

A person’s healthcare team should provide an estimate of the duration before the procedure.

Typically, EP procedures are safe, and any side effects are usually minimal. However, there are some risks, such as:

  • bleeding, bruising, or infection at the entrance site of the catheter
  • arrhythmia that causes dizziness
  • blood clots
  • damage to the heart valves
  • heart attack
  • stroke

The medical team will provide medication to help prevent blood clots and provide other support to help minimize the procedure risks.

An electrophysiology (EP) procedure is a medical intervention that can help diagnose and treat heart rhythm disorders.

EP procedures enable doctors to assess the heart’s electrical activity, identify abnormalities, and deliver targeted therapies to restore normal heart rhythm.

These procedures take place in specialized laboratories, with a skilled team of doctors and nurses ensuring patient comfort and safety throughout the process.