Electrophysiology

An electrophysiology (EP) study tracks and records the electrical activity in your heart. It’s one of the most valuable tools for determining the cause of arrhythmias and the results can be vital for the development of treatment solution to restore stability to your heart’s electrical activity.

During an electrophysiology test, diagnostic catheters are threaded through your veins into your heart. The diagnostic equipment in these catheters can precisely map the electrical currents that cause your heart to beat.

Some patients are given medications during an EP study to modify their heart rate and gauge which treatment options may work best for managing symptoms.

In addition to EP studies, electrophysiology labs can also perform procedures to treat various types of arrhythmia. Using a specially equipped catheter, you’re EP specialist can eliminate or shut down specific electrical pathways that may be causing or contributing to your cardiac arrhythmia during a treatment known as catheter ablation.

Is an Implantable Cardioverter Defibrillators (ICD) right for my arrhythmia?

Implantable cardioverter-defibrillators can help treat life threatening arrhythmias in patients who are at high risk. If a dangerous arrhythmia develops, an ICD can deliver a strong electrical pulse to return your heart to an appropriate rate. These devices are similar to pacemakers but tend to be more powerful and can deliver stronger shocks when necessary.

Not every patient will require an ICD, so you should discuss whether a pacemaker or an ICD would be best for your needs with your primary care doctor and cardiologist.

Why are electrophysiology tests performed?

EP studies are usually performed in response to a specific medical episode or health scare. Some of these include:

• Diagnosis of an abnormal heart rhythm (arrhythmia), which includes conditions such as tachycardia, atrial flutters and atrial fibrillations
• Cardiac ablation procedures
• Syncope or sudden and unexplained loss of consciousness
• Risk of sudden cardiac death

Are EP studies dangerous?

As with virtually every medical procedure, there are potential risks associated with EP studies, but these complications are rare for healthy patients. Some of the most common risks include:

• Damage to blood vessels through which the catheter is passed
• Damage to heart valves or punctures of the heart
• Damage to the electrical system powering the heart
• Blood clots in the legs or lungs

If your cardiologist or primary care doctor recommends undergoing an EP study, it is important to discuss the risks of the procedure prior to beginning the study.

Where are EP studies performed?

Your EP study will be performed at St. Elizabeth’s hospital under the care of a skilled team of cardiologists and specially trained nurses.

Is anesthesia used during an EP study?

The type of sedation used depends on the EP study and how long it is expected to take. In most situations you are simply given a sedative to relax, but some patients may be put under general anesthesia.

Where is the catheter inserted?

Catheter are threaded through the femoral vein, at the top of the leg, to reach the heart and perform EP studies.

What types of tests are performed during an EP study?

Your doctor will place catheters in different parts of the heart and take measurements. The catheters are also equipped with electrodes that can send impulses into your heart to record how it reacts to specific stimuli.

There are several other potential tests that can be run using the diagnostic tools in the catheters.

• A baseline measurement of your heart’s electrical activity can be recorded and mapped to identify irregularities.
• A 3-dimensional map of your heart can be created to visualize the source and path of arrhythmias
• The electrodes on the catheter can be used to make your heart beat faster, slower or even cause an arrhythmia. These tests are precisely controlled and performed in a hospital environment to ensure the patient remains as safe as possible during the study.
• If your cardiologist is attempting to ascertain which medication is best for your heart issues, they may administer them while performing the EP to get a clear, precise picture of exactly what effects they have on your heart rate.
• Patients scheduled for catheter ablation to treat arrhythmia may have an EP study performed first to map out exactly where the ablation will be targeted.

What is catheter ablation?

The treatment is performed using a specially designed catheter that is threaded through a small tube in your groin up to your heart. The goal of catheter ablation is different than EP studies in that the procedure is being performed to treat – not just diagnose – an arrhythmia by terminating the electrical pathways that are responsible for your condition.

A healthy heart’s rhythm is modulated by a complex set of electrical impulses that have to travel through specific pathways in a constant, intricately choreographed pattern. These pathways have the potential to be disrupted in a variety of ways, which interferes with the electrical impulses and can cause arrhythmias or other serious cardiac-related issues to arise.

During catheter ablation, the electrodes on the tip of the catheter are used to send targeted electrical impulses to eliminate abnormal pathways in the heart. Other catheters are able to freeze areas using a balloon cooled to subzero temperatures.

What can catheter ablations be used to treat?

Some of the common types of arrhythmia catheter ablation is used to treat include:

• Atrial fibrillation
• Atrial flutter
• Supraventricular tachycardias (SVT)
• Wolff-Parkinson-White Syndrome (WPW Syndrome)

How effective is catheter ablation?

The procedure boasts a high success rate in the 90 percent range for many types of arrhythmia. The ultimate outcome of your procedure is dependent the specifics of your condition, your heart health and the technician administrating the catheter ablation treatment.

Some of the commonly cited success rates include:

• Wolff-Parkinson-White Syndrome – 95 percent
• Supraventricular Tachycardias – 91 to 96 percent
• Atrial Flutter – 88 to 95 percent
• Automatic Atrial Tachycardias – 70 to 90 percent