What is an electrophysiology study?
An electrophysiology study (EF study) is an invasive examination that is applied for assessment, diagnosis, and treatment of an irregular heart rhythm.
During the EF study, the doctor (a subspecialist in the treatment of cardiac rhythm disorder – electrophysiologist) examines the electrical system of the heart using several special wires (electrode catheters) placed in the heart, through which an intracardiac electrocardiogram (electrogram) is recorded. These electrode catheters are inserted through inserts placed in the veins of the groin, arms, shoulder, or neck.
Once they are positioned in the heart, the electrode catheters are used for measurement of the electrical signals that the heart generates and conducts during its activity. In parallel, electric signals are sent to the heart through the same wires in order to reproduce the abnormal heart rhythm. With these basic techniques, a number of cardiac rhythm disorders are examined, and they are also used for assessment of the efficiency of drug treatment in some arrhythmias.
Your doctor recommended the performance of an EF study due some of the below indicated reasons:
- To treat documented tachycardia
- To locate the source of irregular heart rhythms
- To evaluate the efficiency of prescribed medications in the treatment of irregular heart rhythm
- For assessment of symptoms such as fainting, loss of consciousness, heartbeat
- Assessment of other causes of irregular heartbeat that can not be examined with noninvasive method
Possible risks in the performance of an EF study include:
- Additional impairment of the heart rhythm
- Damage to the normal conductive system during ablation of the arrhythmogenic substrate adjacent to the normal conductive system
- Bleeding and injury to the blood vessel at the site of the sting where the inserts are placed in a vein
- Thromboembolic complications during and after an EF study
- Rare infections at the site of the sting
- Rare episodes of perforation on the heart wall
We recommend that you talk to your doctor about the amount of radiation that you receive as a patient during the procedure and the risk to your health. If you keep a record of exposure to radiation from previous procedures, inform your doctor. The risk associated with irradiation is based on the cumulative effect over time.
For some patients, motionless lying on a chair is a difficulty that can be accompanied by pain. For all these issues, talk to your doctor before performing an EF study.
- Before performing the procedure, you will be asked to sign an approval for a permit to perform an EF study. Therefore please carefully read that document and discuss about everything that is unclear and interests you.
- Your doctor will explain you the EF study and will give you an opportunity to ask questions.
- Tell your doctor if you are allergic to any medicine and / or substance.
- Inform your doctor about ALL medicines and products you consume.
- Do not eat and do not consume liquids on the day of the procedure. Your doctor will inform you about which medicines should no longer be taken and when (before the intervention).
- If you are pregnant or you are not sure, inform the doctor IMMEDIATELY (before the procedure).
- Inform your doctor if you have jewelry on your chest or abdomen.
- Inform your doctor if you have a history of bleeding problems or if you use oral anticoagulation therapy, aspirin or any other medicines that lead to blood thinning. It is likely that the administration of these drugs will be terminated before an EF study is performed.
- On the day of the EF study, your doctor will probably ask for an estimation of the coagulation system in order to assess its condition, as well as some other specific laboratory tests.
- Before the EF study, a sedative may be administered (to reduce preprocedural anxiety). If after the procedure you do not stay in hospital overnight, you need someone to drive you home. After the EF study, it is not allowed to operate the vehicle yourself.
- Depending on your health condition, your doctor may also request some additional tests before an EF study is performed.
Depending on the type of heart disease, your EF study will be performed with hospital or day care. The method of testing depends on the type of heart rhythm disorder and accordingly the number of electrode catheters to be used is determined. In general, the EF study process includes the following moments:
- You need to change your clothes with hospital clothes.
- You will be asked to go to the toilet before the procedure.
- You will be asked to remove your jewelry and / or other items that potentially could obstruct the course of the EF study.
- If there is presence of hair in the area where the inserts are inserted (usually in the groin), it should be removed. This will contribute for rapid healing of the wounds and it will reduce the chance of infection.
- An intravenous line will be placed on one or both hands or arms before the commencement of the EF study. This is for the purpose of applying medications or fluids (if necessary).
- A member of the electrophysiological team will place on you continuous electrocardiographic (ECG) monitoring by means of which your heart activity will be monitored and recorded. Other sensors will also be placed, which will monitor other vital parameters (cardiac and respiratory frequency and oxygen saturation).
- There are several monitors that show your vital parameters and x-ray images from the electrode catheters that are placed in the heart. If you are in a position to follow the procedure on any one of these monitors, this will be provided to you as a possibility.
- You may be given a sedative before the EF study itself, but you will probably be awake during the entire procedure.
- A member of the team will apply to you a local anesthetic in the area where the inserts will be placed through the blood vessels. In doing so, you will feel a mild discomfort at the stinged spot until the anesthetic starts to act. After this, the inserts will be inserted in the blood vessels. An insert is a hollow plastic tube through which electrode catheters are inserted into the blood vessels. They provide unbstructed access to the blood vessel and at the same time they protect the blood vessel from injury.
- During an EF study, one to four electrode catheters are inserted, which under the guidance of X-ray (fluoroscopy) are placed in strategic positions in the heart.
- Once the electrode catheters are positioned, the doctor will begin to apply a series of electrical stimuli in various areas of the heart in order to induce tachycardia. Once it is induced, you will probably feel the quick heart activity. It will be analyzed and then it will be tempered by methods of rapid stimulation, drugs or electric shock.
- For some types of ventricular arrhythmias, it is necessary to perform EF studies in order to assess the risk of malignant arrhythmias and / or sudden cardiac death. In such EF studies, induction of malignant tachycardia is often followed by haemodynamic instability, whereby, electrical cardioversion is applied for normalization of the cardiac rhythm. The haemodynamic stability will determine whether the patient will be sedated before it is performed.
- Sometimes it is necessary to administer drugs of the adrenaline group in order to enable induction of the arrhythmia. Once you have been given such a medication you may feel discomfort or pain in the chest, neck, jaw, back and arm, and it may be followed by a feeling of lack of air or wheezing. These medications have short action and these difficulties soon disappear by themselves. If these difficulties persist for a long time, inform some of the members of the electrophysiology team.
- If it is determined that a certain part of the heart tissue is the cause of the impaired heart rhythm or it is part of the pathway of the pathological heart rhythm, then the doctor will perform catheter ablation to remove this tissue. This is performed with a special ablative catheter that will burn the arrhythmogenic substrate in the heart with high frequency electricity.
- Once the EF study is completed, all inserts and the electrode catheter will be removed. After this, pressure is applied over the stinged spots in order to prevent bleeding and to heal the punctures. Once it has been determined that there is no bleeding from the spots, an elastic bandage is placed over which a sandbag can be put, for additional pressure over the stinged spot.
- The team members will help you move from the work table to your wheelchair, and after this you will be transferred to a hospital room. It is not allowed to bend the leg which was stinged in the next few hours.
- The results of the EF study will allow your doctors to assess whether further treatment is required. In some cases, additional procedures may be required such as the incorporation of a pacemaker or placement of an implantable cardioverter defibrillator. In addition, it may be determined to continue with the same medications or to change the therapy with new medications.
While you are in the hospital
After the EF study, you will be transferred to a hospital room where you will stay in bed for the next few hours, depending on your condition. Occasionally, a nurse will monitor your vital signs and the spots of sting. Inform the staff if you have any difficulties. Under some circumstances, some of the inserts may be left in the blood vessel. You will be in bed until all inserts are removed. After removing all inerts, you will be able to drink liquids and eat an easy meal. After a couple of hours in bed, you would be able to get up with the assistance of someone from the medical staff. After long lying in bed, it is recommendable that you get up from the bed slowly and move carefully so that you will not feel dizzy. You can immediately return to your regular diet unless you are given other specific guidelines.
If you are treated with day care, you are NOT allowed to drive a motor vehicle. Someone should take you home.
Once you return home, check whether you have bleeding in the affected areas. A small bruise is a usual change, however if you notice the following at the spot of the sting wounds:
- cold limb,
- elevated body temperature > 38.0° C with or without fever,
- bleeding, stinging or enlargement of the bruise,
Come immediately to our hospital or call through the Contact Center (02) 309-1484.
It is important to maintain proper hygiene of the wounds and to keep them dry and clean. If you find it necessary, you will be given specific guidelines for wound care.
Several days after the EF study, avoid hard physical activity. The doctor will inform you when you can return to work and when to continue normal daily activities.