Your doctor may have recommended that you undergo an electrophysiology study. This is a procedure where the electrical system of your heart is examined. Arrhythmias, which are abnormal rhythms, slow or fast, can be further evaluated to aid in your treatment. You may have had a loss of consciousness (syncope) or have palpitations which require further investigation. There may be concern that you are susceptible to a fatal rhythm such as ventricular tachycardia and this test may help in determining if you are at risk for this rhythm.
Electrophysiology (EP) Study
An electrophysiology study is performed by placing long electrical wires through catheters into your heart. The procedure may take up to three hours. You will meet several members of the electrophysiology lab team including physicians, nurses, and technicians during this procedure. They are all important in performing the procedure as well as keeping you safe and comfortable.
You will be brought to the electrophysiology laboratory, a sterile room, where you are placed on a table with an x-ray machine. An intravenous line will be placed in your arm. Through this intravenous line, you will be given sedative medicine throughout the study to make you comfortable. Both of your legs where your femoral vein and artery runs will be cleansed as a part of the procedure. Electrodes and large patches will be placed on your chest to monitor your hearts rhythm. The femoral area on your leg will be made numb using lidocaine (which is similar to the medicine the dentist uses).
An electrophysiology study is not painful. There may be some discomfort at the femoral site where the catheters are inserted, but you will not feel the catheters in your body. Let the doctor know if you are experiencing discomfort, chest pain, shortness of breath, or palpitations.
Through these veins and possibly arteries in your leg, catheters are placed into the heart using x-ray to watch its movement and baseline measurements of your electrical system are made. In addition, electrical impulses are sent to stimulate your heart to evaluate your heart’s response, as well as to try and reproduce your arrhythmias.
You may have a rapid and dangerous heart rhythm which may be reproduced such as ventricular tachycardia or ventricular fibrillation. It may be possible that you will pass out. If this happens, the doctor will try and pace your heart out of the rhythm. Sometimes, you may need to be cardioverted (shocked) out of the rhythm.
After the procedure is completed, the catheters are removed and pressure will be held until the bleeding stops. You will be asked to lie flat on the bed without moving your legs for up to four hours. The doctor will talk with you and your family regarding the results of the study. Depending on the results of the test, you may be discharged home afterward.
Overall, an electrophysiology study is a safe procedure. There are risks involved in having this study performed like any other invasive procedure. The risks include damage and bleeding of the vessels where the catheters are inserted and puncturing the heart wall with the catheters causing bleeding around the heart sac and infections. Blood clots and strokes have been reported, and deaths from the procedure are rare.
Ablation is a procedure done in conjunction with the electrophysiology study. If you have a fast arrhythmia which you and your doctor have decided needs to be cured, an ablation may be recommended. After the electrophysiology study is performed, an ablation may be also performed at the same time using the catheters. Through one of the special catheters, radiofrequency energy can be delivered through its tip and a very small area of tissue destroyed.
There are risks involved with radiofrequency ablation in addition to the risks of the electrophysiology study. If the AV node (connection between the upper chambers and lower chambers) is damaged, you may need a pacemaker.
Performing the ablation requires an additional 2 to 4 hours and the total electrophysiology study and ablation may take up to 6 to 8 hours. Because of the length of the procedure and sedation during the procedure, you will most likely stay overnight and be discharged the following day.
A pacemaker is a device which treats slow heart rhythms (bradycardia). The small generator is placed surgically under your skin just below the collarbone. There are one or two wires connected to the generator which go through the blood vessel into your heart. Their electrical impulses are delivered to your heart when needed.
Automatic Implantable Cardioverter Defibrillator (AICD)
Automatic Implantable Cardioverter Defibrillators or (ICD) are for treating rapid life-threatening rhythms. The device is similar to pacemakers, only in addition to treating slow heart rhythms, they treat rapid ones as well. The device generator is larger than the pacemaker. One or two wires will be placed in your heart through blood vessels. There the device can watch every heartbeat and deliver therapies, including shocks, when needed.
If your cardiologist has recommended an ICD for you, we want you to be as informed as possible. We encourage you to visit the Colorado Program for Patient-Centered Decisions website. This site is for patients considering an ICD who are at risk for sudden cardiac death. This website will lead you step-by-step through some information on ICDs that may be helpful. We also hope this will make talking to your doctor easier.