An Electrophysiology (EP) test or study looks at the conduction or electrical system of your heart by recording electrical activity from within the heart chambers. Thin wires are advanced into the heart through a small tube similar to cardiac catheterization to see if the irregular heartbeat can be reproduced. An EP study allows the doctor (Electrophysiologist) to study heart rhythm disturbances (arrhythmias) in a controlled setting.

What does the test show?

The EP study results can help your doctor determine if you have a heart rhythm disturbance or diagnose your abnormal heart rhythm. It can show how well medications work. This information helps determine the best treatment. The test also can be used to see how well your defibrillator (ICD) operates during your abnormal heart rhythm.

In order for your heart to beat, it needs an electrical impulse to generate a heart beat (More information about heart anatomy). Your heart’s natural pacemaker (sinoatrial node) normally makes your heart beat 60-100 times per minute. This is called sinus rhythm. There are conditions when the electrical impulse becomes blocked in its route down the conduction system that cause an abnormal slowing of your rhythm. This is called Bradycardia and refers to a heart rate of less than 60 beats per minute.

In other conditions, an abnormal or “irritable pacemaker” outside the sinoatrial node may cause a very fast heart rhythm to occur. This is called Tachycardia and refers to a heart rate of greater than 100 beats per minute. If the tachycardia comes from the upper chambers of the heart it is called Supraventricular Tachycardia (SVT). If it comes from the lower chambers it is Ventricular Tachycardia (VT).

Either too slow or too fast a heartbeat may cause the following symptoms:

• Dizziness or lightheadedness
• Palpitations (a fluttering or pounding in the chest)
• Fainting spells
• Fatigue
• Shortness of breath
  
  

How do I prepare for the test?

Do not eat or drink anything after midnight the night before your procedure because you need to be fasting for at least 8 hours.
Medications should be taken as scheduled with a sip of water unless special instructions are given to stop your meds. Your doctor may advise you to stop taking certain medications before your EP study to obtain more accurate test results.

Be sure to mention to the doctor or nurse if you have any allergies
Make arrangements with a family member or friend to drive you home after the procedure - you probably will not be permitted to drive. Family members and friends can wait in an assigned area.
Pack a small bag in case your doctor decides to keep you overnight in the hospital. You may want to include a robe, slippers, toiletries, and a book / word games (something to pass the time).
Leave money, jewelry, and valuables at home unless a family member or friend can hold them for you during the procedure.
Bring a list of all medications you are currently taking. Your doctor may want to continue them while you recover from your procedure. Tell your doctor if you take aspirin or a blood thinner because they may need to be stopped several days before the procedure.

Several routine tests are done before the EP study:

• EKG (electrocardiogram)
• Blood tests
• Medical history and exam
• Chest x-ray

Who gets arrhythmias?

Arrhythmias are usually a byproduct of damage to the heart from disease or age. People with otherwise healthy hearts can develop an arrhythmia, but it is rare. Many things can damage your heart’s electrical system and lead to an electrical problem: diseases of the heart valves, enlargement of the heart, coronary artery disease, high blood pressure, lung disease, congenital heart problems (existing at birth) and scarring from a heart attack.

What happens during an Electrophysiology Study?

The Electrophysiology Study may be done as an inpatient or in many cases, as an outpatient. If you are an outpatient, arrive 2 hours before your procedure. Once at the Meijer Heart Center, you will go to the third floor (3 Heart) – Outpatient Care - unless other arrangements have been made. You will change into a hospital gown. An intravenous line (IV) will be started in a vein in your arm and you will be given medication to help you relax. You will be transported to the EP laboratory located on the third floor cardiology unit. You will arrive to the laboratory 30 to 60 minutes before your procedure. Sometimes a scheduled procedure time must be changed due to emergencies.

Once in the EP lab, you will be transferred to a table. Electrodes (sticky patches) will be placed on your chest, back, arms, and legs. You may need to be shaved so the electrodes will stick. You will also be hooked up to other monitoring devices such as a blood pressure cuff and oxygen monitor. You will need to lie still and relax during the test because movement or muscle tensing can interfere with the electrical signals.

The area where the catheters are to be placed (in the groin, arms or neck) will be cleansed with an antiseptic solution. Sterile towels and sheets will be placed over you, leaving exposed only the area where the catheters will be inserted. The doctor will inject a numbing medicine in the areas where the catheters will be inserted. You will feel some stinging at that time. Once the medication takes effect, you should not feel any discomfort.

Once the areas are numb, one to four special insulated wires (called catheters) are inserted into different parts of your heart using a special x-ray machine. This machine allows the doctor to watch the catheters as they move into the correct places. Part of the x-ray machine will be placed directly over your entire body. You will receive only intermittent low dose x-rays.

After the catheters are in position, the doctor evaluates your heart rhythm disturbance by giving your heart small electrical impulses by an artificial pacemaker through one of the catheters. This will make your heart beat at different rates. You may feel your heart beating quickly, or experience fluttering or palpitations. If you feel chest pain or discomfort, let the doctor know.

You may be asked questions during the test such as:
“Do you feel faint?”
“Do you feel your heart pounding?”
“Is this feeling similar to one you have had before?”
“Do you feel dizzy or lightheaded?”
“Are you short of breath?”
“Do you have chest pain or pressure?”

If you do have an irregular rhythm, the doctor may prescribe a cardiac medication. This drug will be given through your IV. You blood pressure, heart rate, oxygen levels will be monitored during this time. Once an adequate dose of the drug is given, the doctor will check to see how effective it is in controlling your irregular rhythm.

What occurs after the procedure?

An EP study usually takes one to four hours.  When the EP study is completed, the doctor will remove the catheters. To prevent bleeding, pressure will be applied to the catheter insertion site until the bleeding stops. A small sterile dressing will be applied which will be removed the next day. No stitches will be required. You will return to a recovery area on a stretcher.

The catheter insertion areas require time to heal, so you will need to follow these steps:

Bed rest for 3-6 hours.
Do not cross your legs and keep the legs straight if the catheters were inserted in the groin. To sit up or bend your knees may cause bleeding at the site.
Report any symptoms to your nurse such as chest pain, swelling in the insertion sites, warmth, anything unusual.
The nurse will make sure you are given something to eat or drink, make sure you are comfortable, answer any questions or concerns, check your blood pressure and heart rhythm (EKG), help you with urination, etc.

Drug therapy for arrythmias

Medication: If the doctor diagnoses you with a heart rhythm disturbance (arrhythmia) after the study, he/she will prescribe a medication (antiarrhythmic) to control your arrhythmia. Antiarrhythmic medications can help alleviate symptoms and prolong life. Some sample medications include:

Quinidine – used to treat patients with Supraventricular (SVT) and Ventricular Arrhythmias (VT), such as Atrial Fibrillation (afib) or flutter, Paroxysmal Supraventricular Tachycardia (PSVT), and Premature Ventricular Contractions (PVCs). The drug comes in several forms, including Quinidine Sulfate (Ci-Quin) and Quinidine Gluconate (Duraquin).

Propranolol (Inderal) – decreases heart rate and contractility. Reduces the incidence of sudden cardiac death after a heart attack.

Sotalol (Betapace) – decreases heart rate, slows AV conduction, decreases cardiac output, and lowers blood pressure.

Amiodarone – used to treat SVT, PSVT, VT, Wolff-Parkinson-White (WPW) syndrome.

*Medications may not be the answer for treating your arrhythmia. If this is the case, your doctor will discuss other ways of treating your problem, such as a pacemaker or defibrillator (AICD).