This page provides information on Electrophysiology (EP) at CCP, for patient education purposes.
Atrial fibrillation is the most common sustained arrhythmia. Over two million Americans are living with atrial fibrillation (AF). Although it is not directly life threatening, it can cause uncomfortable symptoms, such as chest pain, palpitations, shortness of breath, dizziness and fainting. To understand AF, you need to know how the normal heart works.
There are four chambers in the heart, two atria that are the upper chambers and two ventricles, which are the lower chambers of the heart. There is a right and left atrium and a right and left ventricle. An electrical impulse stimulates the heart muscle to contract. The normal electrical conduction starts in the sino-atrial (SA) node sending an impulse through the atria to the atrio-ventricular (AV) node, which will be sent to the ventricles.
With AF, there are several foci of active electrical impulses that cause the atria to fibrillate or quiver. If the impulses are rapidly conducted through the AV node, the ventricular rate can be very fast. Some people experience AF on and off and is classified as paroxysmal. Some people experience AF that needs to be terminated with some type of treatment, which is classified as persistent AF.
Some people remain in AF despite treatment and that is called permanent or chronic AF. Since the atria are not contracting properly in AF, blood clots form in the atria and can travel to the vessels of the head and cause a stroke. For this reason, it is important for people experiencing AF to keep the blood thin with anticoagulation (Coumadin, warfarin or aspirin)
Diagnosis of Atrial Fibrillation
Atrial fibrillation is diagnosed with a 12 lead electrocardiogram (ECG). If it comes and goes it may not be seen on ECG. In this situation, a Holter monitor or event monitor may be helpful. Holter monitor is a 24-48 hour recording of the heart rhythm.
Event monitor is another recording system that records heart rhythm when it is sent by the patient by a device that can either be worn or carried in a pocket. With either model, the monitor is activated when symptoms are felt. The symptomatic recording can then be transmitted through the telephone to a technician who will print out a rhythm strip and send to the physician.
Treatment of Atrial Fibrillation
Some people can be controlled with medications to prevent AF. If AF is diagnosed within 24-48 hours of symptoms, the person can be electrically cardioverted (shocked) back to regular rhythm.
Pulmonary Vein Isolation Ablation Procedure
If frequent episodes of atrial fibrillation are experienced despite adequate medical treatment, ablative therapy may be an option to prevent further episodes. Ablation is when an energy source, currently radio frequency energy, is applied to areas in the heart that are sending abnormal signals. In the case of AF, research shows that the source of AF is often within the pulmonary veins.
Pulmonary veins are veins that bring oxygenated blood from the lungs to the left atrium. In some people atrial muscle extends within the pulmonary veins. These muscular sleeves are able to send electrical activity such as atrial muscle and also able to conduct. The coalition of normal impulse with the pulmonary vein impulse can cause chaotic rhythm or atrial fibrillation.
Once ablation procedure is decided, you will need a CT scan of the chest to evaluate the anatomy of your pulmonary veins. Prior to the procedure, you will also need blood work. You will be expected to fast from midnight on the morning of the procedure and instructions in reference to your medications will be given in advance.
The electrophysiology laboratory is a large room with a lot of equipment including monitors and an X-ray machine. The room is sterile and the doctors are wearing sterile outfits. You will be covered with special drapes. You will be sedated by an anesthesiologists and keep comfortable throughout the procedure. After injecting a local anesthetic, catheters will be inserted into the veins in your groin and will be advanced under fluoroscopic (X-ray) guidance to the heart and through the septum (the wall between left and right atria) to the left atrium to access the pulmonary veins.
After finding the electrical activities of the pulmonary veins, radiofrequency energy is delivered through a special catheter. Ablation cauterizes abnormal tissue, making it incapable of transmitting electrical impulses. Radiofrequency energy is applied in a circular pattern at the opening of all pulmonary veins. The entire procedure can take up to 5-6 hours.
After the procedure you will be brought to the recovery room next to the EP laboratory and monitored while the sedating medications wear off, then you will be transferred to a monitored room for an overnight stay. It is not unusual to feel some discomfort in your chest area and in your groin areas where the catheters were inserted. You may also feel some skipped beats. When you are ready to go home the next day you will be given special instructions about how to take care of your groin, what medications to take and what symptoms you may expect to feel.
It is not unusual to experience AF for 1-3 months after the procedure. You will be monitored with an event monitor for one month after the procedure. You will be probably discharged on the same medications as before the ablation procedure. Coumadin will be started in the hospital as well as Lovenox (injectable heparin). Lovenox will be continued for three days but Coumadin for 1-3 months based on discretion of your doctor.
You will be asked to come to your doctor's office in one month. At that time, another CT scan of the chest will be ordered to reevaluate pulmonary veins anatomy after ablation.
After your ICD is implanted you will be scheduled for and office appointment with the nurse practitioner in 1-2 weeks. Your incision site will be checked to make sure there are no signs of infection and that it is healing normally. Your ICD will be tested by using a special computer and placing a wand over your ICD device. You should not have any discomfort with this test.
You will then be scheduled for similar appointments in 1 month and then every 3 to 4 months after implant. These visits allow us to insure that your ICD is functioning appropriately and to see if you have had any abnormal heart rhythms. Some models of ICDs may be capable of remote follow-up using a telephone system.
Eventually you will be seen every 3 to 4 months for ICD evaluations, each visits takes approximately 20 minutes. Patients whose ICDs can be evaluated by telephone generally only require visits to check their ICDs once yearly, unless problems or frequent arrhythmias occur.
After your ICD implant, your doctor may schedule you to have a NIPS test. This can be done the day after implant while you are still in the hospital or as an outpatient up to several months after implant. This test is done to insure that the device appropriately senses abnormal fast heart beats and successfully stops this abnormal rhythm with either overdrive pacing or defibrillation shock.
In order to do this test, your doctor will use a special computer and your implanted ICD to put your heart into ventricular tachycardia or ventricular fibrillation. Since you will be receiving a shock from your ICD you will receive anesthesia through an intravenous (IV) access during the testing. This test usually takes 15 minutes.
You should plan to stay in the hospital for several hours to allow registration prior to the test and 1-2 hours after the test to fully recover from the anesthesia. You may take your morning medicine with small sips of water. You will need to have someone drive you home form the hospital as you will not be permitted to drive on the day of the test due to the use of anesthesia.
General pre-procedure testing includes blood work and instructions not to eat or drink after 12 midnight the night prior to the test.
After your pacemaker is implanted you will be scheduled for an office visit with the nurse practitioner in 1-2 weeks. Your pacemaker incision will be checked to make sure there are no signs of infection. Your pacemaker will be evaluated by using a special computer and placing a wand over your pacemaker.
You will be seen again in 1-3 months after pacemaker implant for routine testing and adjustment of pacemaker parameters. After the initial adjustments and checks, your pacemaker will need to be checked in the office at intervals of 6 to 12 months. These tests take approximately 20 minutes and provide detailed information on the pacing leads and pacemaker function.
Telephone follow-up of your pacemaker
At the 3 months visit, you may be set up to have transtelephonic testing of your pacemaker. You will be given a special telephone testing device to take home with you and will begin having telephone checks every other month. When the pacemaker battery has begun to deplete, these checks may be performed monthly.
These checks take approximately 5 minutes and test basic pacemaker function and battery status. Because office pacemaker evaluations provide much more detailed information regarding pacemaker function and the heart rhythm function of your heart, transtelephonic follow-up of your pacemaker complements but does not replace office visits.