The electrophysiological test (EPS) is a very specialized, invasive test performed in people with suspected arrhythmias, but also with diagnosed arrhythmia. Find out when such a test is performed, what it is and how the procedure itself is carried out.

Contents:

  1. Conductive system
  2. Electrophysiological test - when is it done?
  3. Preparation for electrophysiological examination
  4. The course of the electrophysiological test
  5. Electrophysiological examination - complications

The electrophysiological testis an advanced, invasive test of the electrical activity of the heart. It involves mapping electrical potentials and diagnostic cardiac pacing with the use of intracardiac electrodes inserted through the vessels - most often the femoral vein.

Electrophysiological examination allows to determine the exact type of heart rhythm disturbances, assess the condition of the conduction system and implement appropriate treatment: pharmacological or surgical - percutaneous ablation.

Electrophysiological examination is safe and usually painless, only in some people pacing may feel like palpitations. It is worth knowing that the electrophysiological test is always performed before the ablation procedure.

Contemporary cardiology more and more often uses invasive methods of both diagnostics and treatment. Current medical knowledge allows for a therapy based not only on pharmacological treatment, but also on, often more effective, surgical treatment.

Hemodynamics laboratories diagnosing and treating ischemic heart disease, including heart attacks, are available on a large scale.

The same applies to the so-called implantable devices - pacemakers, their task is to treat, among others, slow heart rhythms.

The field of cardiology called electrophysiology is also gaining more and more importance, it deals with the diagnosis and treatment of cardiac arrhythmias based primarily on ECG records, Holter tests, but also electrophysiological tests.

The main purpose of such a study is a thorough assessment of cardiac arrhythmias, their origins, and thus the selection of an appropriate therapy.

Conductive system

The conductive system is a complicated structurebuilt into the heart responsible for generating and conducting impulses. It is responsible for the so-called automatism of the heart, which is the autonomous (self) stimulation of the heart to work.

In the right atrium of the heart there is a sinus node - a pacemaker, this area generates electrical discharges which, when spreading, cause the heart muscle to contract.

After being created in the sinus node, the stimulus spreads through the atria, stimulating them to work and fill the ventricles with blood.

The impulse then travels through the atrioventricular node, bundle branches, and Purkinje fibers to the ventricles, which also activate and contract when it arrives.

Blood is ejected into large vessels and the cycle begins again.

Such an operation of the conductive system ensures that the heart is stimulated frequently, both in terms of its frequency - e.g. acceleration of action during exercise, and the proper spreading of stimuli. Irregularities in the electrical work of the heart can result from various mechanisms:

  • impulse generation disorders in the sinus node
  • incorrect impulse conduction resulting from damage to the conductive system
  • the appearance of areas responsible for the production of impulses in the heart muscle, outside the sinus node
  • the appearance of areas of the heart muscle that do not conduct electrical impulses properly - both too slowly and too quickly

Each of these situations may cause arrhythmias which, apart from the troublesome symptoms, may be hazardous to he alth and life. The above-mentioned abnormalities in the conduction of electrical impulses are caused, among others, by:

  • age
  • hypertension
  • recent heart attacks
  • other heart diseases

Electrophysiological test - when is it done?

Not every person with cardiac arrhythmias should have an electrophysiological test. The candidate is eligible for the procedure on the basis of ailments and the results of other tests:

  • EKG
  • Holter EKG testing
  • heart echo

In many cases it is also important to exclude the occurrence of diseases that may contribute to arrhythmia, e.g. ischemic heart disease or thyroid diseases. An electrophysiological test is performed to evaluate:

  • sources of arrhythmias - the exact location of the area in the heart muscle responsible for the arrhythmia
  • effectiveness of pharmacological treatment of cardiac arrhythmias
  • possibility and necessity to doablation
  • in diagnosis of loss of consciousness if an arrhythmic background is suspected

Preparation for electrophysiological examination

As before any invasive examination, it is worth having a vaccination against hepatitis B, as well as basic tests: blood count, electrolyte tests.

Conducting an electrophysiological test in most cases requires only a little preparation: shaving the vascular access sites - most often the groin and, of course, fasting. Sometimes it is also necessary to modify pharmacotherapy - discontinuation of some antiarrhythmic drugs and drugs that inhibit blood clotting.

The doctor who conducts the electrophysiological examination informs about the necessity of such a procedure. After the procedure, you should lie flat on your back for several hours to allow the punctured vessel to heal, save the punctured leg for about a week, i.e. do not make strenuous efforts, bend over and do squats to avoid bleeding.

The course of the electrophysiological test

The electrophysiological test is a minimally invasive procedure, i.e. performed vascularly without the need to open the chest. It is performed in the electrophysiology laboratory - a special diagnostic and treatment room.

After the subject is placed on the treatment table, the area of ​​the vascular access is disinfected and covered with sterile drapes. Then local anesthesia is administered and access to the vein is obtained - usually the femoral (in exceptional cases, the procedure is performed through the artery).

Sometimes, apart from local anesthesia, it is necessary to administer sedatives.

The doctor punctures the vessel, introduces the guidewire one by one, and then the catheter into the heart. The next stage is the introduction of special electrodes for carrying out the test.

The electrophysiological examination is carried out under the control of the X-ray image, it allows to visualize the electrodes and place them properly (in the right atrium and ventricle, the area of ​​the His bundle and the coronary sinus). Their task is to register and analyze the electrical potentials of the heart, and thanks to the fact that it happens inside the heart, they can be assessed very accurately.

The electrodes are also used to send stimuli - the heart is stimulated to induce arrhythmias under controlled conditions. Sometimes it is also necessary to stimulate the heart to work faster and even induce an arrhythmia, which can be unpleasant, but it is necessary for the procedure to be effective.

After making the so-called electrical map, i.e. visualization of the heart with its electrical potentials,a decision is made whether the procedure is completed or ablation is performed simultaneously.

In the first case, the electrodes and the catheter are removed, and a dressing and sometimes a single suture are placed over the puncture site.

However, if the doctor decides to perform ablation, a catheter is inserted to destroy the sites responsible for the production of arrhythmias.

The electrophysiological test can be very long - up to several hours.

Electrophysiological examination - complications

Complications are very rare - less than 1%. The most dangerous, and at the same time the rarest, is the perforation of the heart muscle, i.e. the creation of a fissure in the free wall of the heart through which blood is extravasated, leading to a cardiac tamponade. It is then necessary to puncture the pericardial sac, and sometimes perform a cardiac surgery. Other possible complications are:

  • damage to the conductive system, which results in a slow heart rate and the need to implant a pacemaker
  • damage to the vascular access site, causing hematomas, less often pseudoaneurysms, which in exceptional circumstances have to be operated on
  • infection
  • pneumothorax
  • occurrence of embolism episodes - organ ischemia, e.g. stroke

The vast majority of patients do not experience any complications.

About the authorBow. Maciej GrymuzaA graduate of the Faculty of Medicine at the Medical University of K. Marcinkowski in Poznań. He graduated from university with an over good result. Currently, he is a doctor in the field of cardiology and a doctoral student. He is particularly interested in invasive cardiology and implantable devices (stimulators).

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Research