Electrophysiology is a study of the heart’s electrical system to test for abnormal heart rhythm. In this article, we will look at how electrophysiology can help to diagnose and potentially treat heart conditions and arrhythmias; covering the different cardiac electrophysiology procedures, how electrophysiology is performed, its benefits, and more.
What is electrophysiology?
Contractions in the various sections of the heart are coordinated by natural electrical impulses. This movement keeps blood flowing and creates the heart’s rhythm. A cardiac electrophysiology study is performed to assess the heart’s electrical activity and diagnose arrhythmias. The test uses catheters and wire electrodes to measure electrical activity.
Electrophysiology of heart and arrhythmias
Electrophysiology can help to detect a range of arrhythmia-related conditions, including:
- Atrial fibrillation
- Atrial flutter
- Sick sinus syndrome
- Heart blocks
- Postural orthostatic tachycardia syndrome
- Familial arrhythmia syndrome
- Supraventricular tachycardia
- Ventricular arrhythmias
- Syncope
This diagnostic procedure can measure the heart’s electrical conduction, arrhythmia episodes, and blood or heart pressure changes. The electrical images produced by electrophysiology studies can help to determine if the heart is functioning as it should be.
Electrophysiology techniques
There are various types of cardiac electrophysiology procedures, falling into the categories of non-invasive electrophysiology and clinical electrophysiology.
Non-invasive electrophysiology techniques include:
- Endless electrocardiogram loop
- ECG-event monitoring
- Signal-averaged EKG testing
- New technologies for the analysis of heartbeat irregularities arrhythmias
- 24 hour Holter monitoring
Clinical electrophysiology procedures include:
- Implantable cardioverter defibrillators (ICD) implantation
- Pacemaker implantation
- Catheter-based ablation for complex ventricular and supraventricular tachyarrhythmias
- Catheter-based ablation for atrial flutter and atrial fibrillation
- Laser-assisted lead extraction of non-functional devices
- Palpitations evaluation
- Syncope evaluation
How is an electrophysiology study performed?
Ahead of a standard electrophysiology procedure, you will remove your clothing and jewelry and wear a hospital gown. If you have a lot of hair around the area where the catheter will be inserted, it may need to be shaved off to help healing after the procedure. If required, an intravenous (IV) line will be placed in your arm or hand to provide IV fluids and medicine. You may be given a sedative for relaxation.
You will be connected to an ECG monitor that can display your heart’s electrical activity via small electrodes. Vitals signs such as blood pressure, heart rate, oxygen level and breathing rate can also be monitored.
A local anesthetic will be administered. After the anesthetic has taken effect, an introducer (sheath or plastic tube through which the catheter will be put) will be inserted. One or several catheters will be put through the introducer; they will help to protect the surrounding blood vessels from trauma.
Once in place, your doctor can send small electrical impulses to areas of the heart. You might feel your heart beating faster or stronger at this time. Depending on the procedure, a shock may be given or medicine may be administered to stop arrhythmias. In some cases, an ablation may be required for the destruction of abnormal tissue.
After the electrophysiology study is completed, the catheter is removed and a tight bandage is applied, sometimes held in place by a small weight. You will then be taken to the recovery area. The results of an electrophysiology study can help your doctor to determine if further treatment is needed, and if so, which treatment is most suitable.
What are the benefits of cardiac electrophysiology?
Among the benefits of cardiac electrophysiology are:
- Able to gain more information on arrhythmias (heart rhythms that are abnormally fast or slow)
- Effective in determining arrhythmias when other tests have been inconclusive
- Provide doctors with information that helps determine the best course of action
- Can evaluate symptoms like fainting, dizziness, palpitations or weakness
- Used for checking how well medicines for arrhythmias are working
- Able to identify the source of arrhythmias and enable an ablation to be done once found
How accurate is a cardiac electrophysiology test?
A cardiac electrophysiology test is relied upon as the most accurate method for heart rhythm evaluation. Because it is able to record the heart’s electrical activity with the use of small electrical impulses, an electrophysiology study allows doctors to identify and analyze arrhythmias, before deciding on the best treatment route.
EP lab vs cath lab
A cardiac catheterization, also known as a cath lab, monitors the heart and major blood vessels’ anatomical structures, identifying blockages, monitoring the function of valves and checking blood flow. During the procedure, a catheter is guided into the heart, and a contrast dye is injected into the blood vessel, allowing x-ray videos of the heart – including its chambers, valves and arteries – to be created.
An electrophysiology (EP) lab and cath lab both use a catheter as part of the procedure, but rather than examining the heart’s anatomy and blood flow, an EP lab focuses specifically on the examination of the heart’s electrical system, and typically involves more ancillary equipment. Furthermore, a standard electrophysiology test is much less invasive than a cath lab test.
Electrophysiology imaging
Real-time cardiac imaging is vital to today’s cardiac electrophysiology procedures. The accurate definition of the cardiac anatomy is critical to the success of procedures, offering superior visualization of soft tissues to techniques that use 2D imaging, such as fluoroscopy.
Advanced 3D mapping systems are allowing electrical intracardiac mapping and real-time catheter localization. When they are merged with computed tomography images, mapping systems can offer accurate electrical and anatomic heart maps for the guidance of catheter ablations.
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Sources:
https://stanfordhealthcare.org/medical-tests/e/electrophysiology-study.html