An electrophysiological study (EP study) is a test used to evaluate your heart’s electrical system and to check for abnormal heart rhythms. Natural electrical impulses coordinate contractions of the different parts of the heart. This helps keep blood flowing the way it should. This movement of the heart creates the heartbeat, or heart rhythm.

When someone’s heart doesn’t beat normally, doctors use EPS to find out why. Electrical signals usually travel through the heart in a regular pattern. Heart attacks, aging and high blood pressure may cause scarring of the heart. This may cause the heart to beat in an irregular (uneven) pattern. Extra abnormal electrical pathways found in certain congenital heart defects can also cause arrhythmias.

Invasive Services

Loop Recorder Implant

An implantable loop recorder, or ILR, is a heart recording device that is implanted in the body underneath the chest skin. It has several uses. The most common ones include looking for causes of fainting, palpitations, very fast or slow heartbeats, and hidden rhythms that can cause strokes. During a loop recorder implantation, your heart healthcare provider (cardiologist) does a minor procedure. He or she places the small device under your skin, on your chest wall, overlying the heart. The machine works as an electrocardiogram (ECG), continuously picking up electrical signal from your heart. This can help find abnormal heart rhythms that can cause a number of problems such as fainting.

Normally, a special group of cells begin the electrical signal to start your heartbeat. These cells are in the sinoatrial (SA) node. This node is in the right atrium, the upper right chamber of your heart. The signal quickly travels down your heart’s conducting system to the ventricles. These are the 2 lower chambers of your heart. As it travels, the signal triggers nearby parts of your heart to contract. This helps your heart pump blood in a coordinated way.

Any disruptions to this signaling pathway may result in heart rhythm problems. These might cause a number of problems, such as fainting and palpitations. An abnormal heart rhythm (arrhythmia) may make your heart unable to pump as much blood as needed. The temporarily reduced blood to your brain is what causes you to faint. When the rhythm returns to normal, you normally regain consciousness.

Each heart rhythm problem may need its own treatment. It’s important to find out what kind of problem you may have, if any. An implantable loop recorder continuously records information about your electrical activity, similar to an ECG. However, an implantable loop recorder can record heart rhythm for up to 3 years. It is continuously looping its memory and has automatic triggers to store recordings. It can also be patient activated to store recordings as well. If you fainted due to an arrhythmia, the machine records this information before, during, and after the fainting. Then a healthcare provider can look at the recordings to figure out the cause.

Why might I need a loop recorder implanted?

You might need a loop recorder if you have fainting episodes or palpitations, and other tests have not yet given you any answers. Repeated fainting can have a negative effect on your physical and emotional health. Also, certain kinds of fainting greatly increase your chance for sudden death. These fainting episodes require diagnosis and treatment as soon as possible. Once you are diagnosed, you may need a pacemaker or an implantable cardioverter-defibrillator (ICDs). These could save your life. You might also need a loop recorder if your healthcare provider wants to look for very fast or slow heartbeats. These abnormal heartbeats can cause palpitations, or even lead to strokes.

If you have a problem with fainting, your healthcare provider will look at various causes. Only certain kinds of fainting are due to abnormal heart rhythms. Your healthcare provider will probably start with basic tests like an electrocardiogram (ECG). This records your heart rhythm only for a few seconds, however. So, your healthcare provider may not be able to analyze the specific rhythm problem that causes your fainting. He or she might have tried other sorts of tests, like Holter monitoring, tilt-table testing, or electrophysiologic studies of your heart.

Loop recorder implantation is often helpful if other tests haven’t found the cause. Your healthcare provider is more likely to recommend it if your heart is a likely cause of your fainting. This is more common in the elderly. It is also more common in people with other heart problems. You are also more likely to need loop recorder implantation if you are fainting frequently, but not enough for other kinds of heart rhythm monitoring to detect your fainting. Because the loop recorder records for up to 3 years, your healthcare provider should eventually be able to analyze your heart rhythms during a fainting episode.

You also might need a loop recorder if you are an older adult with unexplained falls. Healthcare providers sometimes use it in people believed to have epilepsy who have not responded to medicine. In both cases, the recorder can determine whether an abnormal rhythm is the problem.

What are the risks for loop recorder implantation?

Most people have the procedure without any problems. However, sometimes problems happen. These might include:

• Bleeding or bruising
• Infection (might require device removal)
• Damage to your heart or blood vessels
• Mild pain at your implantation site

Your own risks will depend on your age, your other medical conditions, and other factors. Ask your healthcare provider about any risks of the procedure for you.

How do I prepare for a loop recorder implantation?

Talk with your healthcare provider about what you should do to prepare for your procedure. You may need to avoid eating or drinking anything before the midnight before your procedure. Follow your healthcare provider’s instructions about what medicines to take before the procedure. Don’t stop taking any medicine unless your provider tells you to do so. He or she might order tests before the procedure, like an ECG.

What happens during a loop recorder implantation?

Ask your healthcare provider about what to expect during your procedure. Normally, you can expect the following:

• You may be given medicine to help you relax.
• A local anesthetic will be put on your skin to numb it.
• Your healthcare provider will make a small incision in your skin. This is usually done in the left upper chest.
• Your healthcare provider will create a small pocket under your skin. He or she will place the loop recorder in this pocket. The machine is about the size of a flat AA battery.
• Your incision will be closed with sutures. A bandage will be put on the area.

What happens after a loop recorder implantation?

Ask your healthcare provider about what to expect after your procedure. In most cases:

• You will be able to go home the day of the procedure.
• You can ask for pain medicine if you need it.
• You will need someone to drive you home after the procedure.
• You can return to normal after the procedure. But you may want to rest.
• Tell your healthcare provider if you have bleeding or swelling at the insertion site.

All loop recorders come programmed to record certain fast and slow heart rates. However, they also come with a handheld activator that tells the loop recorder to save the signals collected over a certain period of time. This is important because it can also help explain if a fast or slow heartbeat is not what is causing your problems. Someone will make sure you know how to use your activator before you go home.

Talk with your heart healthcare provider first if another healthcare provider wants you to get an MRI test. It may cause your device to display a false reading.

You may keep your loop recorder for up to 2 or 3 years. When you no longer need it, you will need to have it removed in a similar procedure.

Pacemaker Implant

A pacemaker insertion is the implantation of a small electronic device that is usually placed in the chest (just below the collarbone) to help regulate slow electrical problems with the heart. A pacemaker may be recommended to ensure that the heartbeat does not slow to a dangerously low rate.

A pacemaker is composed of three parts: a pulse generator, one or more leads, and an electrode on each lead. A pacemaker signals the heart to beat when the heartbeat is too slow or irregular.
A pacemaker may be inserted in order to stimulate a faster heart rate when the heart is beating too slowly, and causing problems that cannot otherwise be corrected.

A pacemaker may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor’s practices.

Generally, a pacemaker insertion follows this process:

• You will be asked to remove any jewelry or other objects that may interfere with the procedure.
• You will be asked to remove your clothing and will be given a gown to wear.
• You will be asked to empty your bladder prior to the procedure.
• If there is excessive hair at the incision site, it may be clipped off.
• An intravenous (IV) line will be started in your hand or arm prior to the procedure for injection of medication and to administer IV fluids, if needed.
• You will be placed on your back on the procedure table.
• You will be connected to an electrocardiogram (ECG or EKG) monitor that records the electrical activity of the heart and monitors the heart during the procedure using small, adhesive electrodes. Your vital signs (heart rate, blood pressure, breathing rate, and oxygenation level) will be monitored during the procedure.
• Large electrode pads will be placed on the front and back of the chest.
• You will receive a sedative medication in your IV before the procedure to help you relax. However, you will likely remain awake during the procedure.
• The pacemaker insertion site will be cleansed with antiseptic soap.
• Sterile towels and a sheet will be placed around this area.
• A local anesthetic will be injected into the skin at the insertion site.
• Once the anesthetic has taken effect, the physician will make a small incision at the insertion site.
• A sheath, or introducer, is inserted into a blood vessel, usually under the collarbone. The sheath is a plastic tube through which the pacer lead wire will be inserted into the blood vessel and advanced into the heart.
• It will be very important for you to remain still during the procedure so that the catheter does not move out of place and to prevent damage to the insertion site.
• The lead wire will be inserted through the introducer into the blood vessel. The doctor will advance the lead wire through the blood vessel into the heart.
• Once the lead wire is inside the heart, it will be tested to verify proper location and that it works. There may be one, two, or three lead wires inserted, depending on the type of device your doctor has chosen for your condition. Fluoroscopy, (a special type of X-ray that will be displayed on a TV monitor), may be used to assist in testing the location of the leads.
• The pacemaker generator will be slipped under the skin through the incision (just below the collarbone) after the lead wire is attached to the generator. Generally, the generator will be placed on the nondominant side. (If you are right-handed, the device will be placed in your upper left chest. If you are left-handed, the device will be placed in your upper right chest).
• The ECG will be observed to ensure that the pacer is working correctly.
• The skin incision will be closed with sutures, adhesive strips, or a special glue.
• A sterile bandage or dressing will be applied.

Intracardiac Defibrillator Implant

An implantable cardioverter-defibrillator (ICD) is a small battery-powered device placed in your chest to monitor your heart rhythm and detect irregular heartbeats. An ICD can deliver electric shocks via one or more wires connected to your heart to fix an abnormal heart rhythm.

You might need an ICD if you have a dangerously fast heartbeat (ventricular tachycardia) or a chaotic heartbeat that keeps your heart from supplying enough blood to the rest of your body (ventricular fibrillation). Ventricles are the lower chambers of your heart.

ICDs detect and stop abnormal heartbeats (arrhythmias). The device continuously monitors your heartbeat and delivers electrical pulses to restore a normal heart rhythm when necessary. An ICD differs from a pacemaker — another implantable device used to help control abnormal heart rhythms.

Why it’s done

You’ve likely seen TV shows in which hospital workers “shock” an unconscious person out of cardiac arrest with electrified paddles. An ICD does the same thing only internally and automatically when it detects an abnormal heart rhythm.

An ICD is surgically placed under your skin, usually below your left collarbone. One or more flexible, insulated wires (leads) run from the ICD through your veins to your heart.

Because the ICD constantly monitors for abnormal heart rhythms and instantly tries to correct them, it helps when your heart stops beating (cardiac arrest), even when you are far from the nearest hospital.

How an ICD works

When you have a rapid heartbeat, the wires from your heart to the device transmit signals to the ICD, which sends electrical pulses to regulate your heartbeat. Depending on the problem with your heartbeat, your ICD could be programmed for:

• Low-energy pacing. You may feel nothing or a painless fluttering in your chest when your ICD responds to mild disruptions in your heartbeat.
• A higher-energy shock. For more-serious heart rhythm problems, the ICD may deliver a higher-energy shock. This shock can be painful, possibly making you feel as if you’ve been kicked in the chest. The pain usually lasts only a second, and there shouldn’t be discomfort after the shock ends.

Usually, only one shock is needed to restore a normal heartbeat. Sometimes, however, you might have two or more shocks during a 24-hour period.

Having three or more shocks in a short time period is known as an electrical or arrhythmia storm. If you have an electrical storm, you should seek emergency care to see if your ICD is working properly or if you have a problem that’s making your heart beat abnormally.

If necessary, the ICD can be adjusted to reduce the number and frequency of shocks. You may need additional medications to make your heart beat regularly and decrease the chance of an ICD storm.

An ICD can also record the heart’s activity and variations in rhythm. This information helps your doctor evaluate your heart rhythm problem and, if necessary, reprogram your ICD.

Subcutaneous ICD

Subcutaneous implantable cardioverter-defibrillator (S-ICD)Open pop-up dialog box
A subcutaneous ICD (S-ICD) is a newer type of ICD available at some surgical centers. An S-ICD is implanted under the skin at the side of the chest below the armpit. It’s attached to an electrode that runs along your breastbone.
You may be a candidate for this device if you have structural defects in your heart that prevent inserting wires to the heart through your blood vessels, or if you have other reasons for wanting to avoid traditional ICDs. Implanting a subcutaneous ICD is less invasive than an ICD that attaches to the heart, but the device is larger in size than an ICD.

Who needs an ICD

You’re a candidate for an ICD if you’ve had sustained ventricular tachycardia, survived a cardiac arrest or fainted from a ventricular arrhythmia. You might also benefit from an ICD if you have:

• A history of coronary artery disease and heart attack that has weakened your heart.
• A heart condition that involves abnormal heart muscle, such as enlarged or thickened heart muscle.
• An inherited heart defect that makes your heart beat abnormally. These include long QT syndrome, which can cause ventricular fibrillation and death even in young people with no signs or symptoms of heart problems.
• Other rare conditions that may affect your heart rhythm.

Risks

Risks associated with ICD implantation are uncommon but may include:

• Infection at the implant site
• Allergic reaction to the medications used during the procedure
• Swelling, bleeding or bruising where your ICD was implanted
• Damage to the vein where your ICD leads are placed
• Bleeding around your heart, which can be life-threatening
• Blood leaking through the heart valve where the ICD lead is placed
• Collapsed lung (pneumothorax)

How you prepare

To determine whether you need an ICD, your doctor might perform a variety of diagnostic tests, which may include:

• Electrocardiography (ECG). This noninvasive test uses sensor pads with wires attached (electrodes) placed on your body to measure your heart’s electrical impulses. Your heart’s beating pattern offers clues to the type of irregular heartbeat you have.
• Echocardiography. This noninvasive test uses harmless sound waves that allow your doctor to see your heart without making an incision. During the procedure, a small instrument called a transducer is placed on your chest to collect reflected sound waves (echoes) from your heart and transmit them to a machine that uses the sound wave patterns to compose images of your beating heart on a monitor. These images show how well your heart is functioning and the size and thickness of your heart muscle.
• Holter monitoring. Also known as an ambulatory electrocardiogram monitor, a Holter monitor records your heart rhythm for 24 hours. Wires from electrodes on your chest go to a battery-operated recording device carried in your pocket or worn on a belt or shoulder strap.
• While wearing the monitor, you’ll keep a diary of your activities and symptoms. Your doctor will compare the diary with the electrical recordings and try to figure out the cause of your symptoms.
• Event recorder. Your doctor might ask you to wear a pager-sized device that records your heart activity for more than 24 hours. Unlike a Holter monitor, it doesn’t operate continuously — you turn it on when you feel your heart is beating abnormally.
• Electrophysiology study (EPS). Electrodes are guided through blood vessels to your heart and used to test the function of your heart’s electrical system. This can identify whether you have or might develop heart rhythm problems.

Food and medications

You’ll probably need to fast for at least eight hours before your surgery. Talk to your doctor about any medications you take and whether you should continue to take them before your procedure to implant an ICD.

What you can expect

During the procedure

Usually, the procedure to implant an ICD can be performed with numbing medication and a sedative that relaxes you but allows you to remain aware of your surroundings. In some cases, general anesthesia may be used so that you’re unconscious for the procedure.

During surgery, one or more flexible, insulated wires (leads) are inserted into veins near your collarbone and guided, with the help of X-ray images, to your heart. The ends of the leads are secured to your heart, while the other ends are attached to the generator, which is usually implanted under the skin beneath your collarbone. The procedure usually takes a few hours.

Once the ICD is in place, your doctor will test it and program it for your heart rhythm problem. Testing the ICD might require speeding up your heart and then shocking it back into normal rhythm.

After the procedure

You’ll usually be released on the day of your surgery, once the anesthesia has worn off. You’ll need to arrange for a ride home because you won’t be able to drive right away.

Because some defibrillators have leads placed through the veins into the heart, you’ll need to avoid abrupt movements that raise your left arm above shoulder-height for two to three weeks. This is so the leads don’t move until the area has had time to heal. That also means no driving during that time.

If you got a subcutaneous defibrillator, there are no leads placed through the veins, so there aren’t any restrictions on driving or lifting your arm above your shoulder.

Treating pain after your procedure

After surgery, you may have some pain in the incision area, which can remain swollen and tender for a few days or weeks. Your doctor might prescribe pain medication.

As your pain lessens, you can take an over-the-counter pain reliever, such as acetaminophen. Aspirin and ibuprofen aren’t recommended because they may increase your risk of bleeding.

Unless your doctor instructs you to do so, don’t take pain medication containing aspirin because it can increase the risk of bleeding.

Results

ICDs have become standard treatment for anyone who has survived cardiac arrest, and they’re increasingly used in people at high risk of sudden cardiac arrest. An ICD lowers your risk of sudden death from cardiac arrest more than medication alone.

Although the electrical shocks can be unsettling, they’re a sign that the ICD is effectively treating your heart rhythm problem and protecting you from sudden death. Talk to your doctor about how to best care for your ICD.

After the procedure, you’ll need to take some precautions to avoid injuries and make sure your ICD works properly.

Short-term precautions

You’ll likely be able to return to normal activities soon after you recover from surgery. Follow your doctor’s instructions. For four weeks after surgery, your doctor might ask you to refrain from:

• Vigorous above-the-shoulder activities or exercises, including golf, tennis, swimming, bicycling, bowling or vacuuming
• Lifting anything heavy
• Strenuous exercise programs

Your doctor will probably advise you to avoid contact sports indefinitely. Heavy contact may damage your device or dislodge the wires.
Long-term precautions
Problems with your ICD due to electrical interference are rare. Still, take precautions with the following:

• Cellular phones and other mobile devices. It’s safe to talk on a cellphone, but avoid placing your cellphone within 6 inches (about 15 centimeters) of your ICD implantation site when the phone is turned on. Although unlikely, your ICD could mistake a cellphone’s signal for a heartbeat and slow your heartbeat, causing symptoms such as sudden fatigue.
• Security systems. After surgery, you’ll receive a card that says you have an ICD. Show your card to airport personnel because the ICD may set off airport security alarms.
• Also, hand-held metal detectors often contain a magnet that can interfere with your ICD. Limit scanning with a hand-held detector to less than 30 seconds over the site of your ICD or make a request for a manual search.
• Medical equipment. Let doctors, medical technicians and dentists you see know you have an ICD. Some procedures, such as magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and radiofrequency or microwave ablation are not recommended if you have an ICD.
• Power generators. Stand at least 2 feet (0.6 meters) from welding equipment, high-voltage transformers or motor-generator systems. If you work around such equipment, your doctor can arrange a test in your workplace to see if the equipment affects your ICD.
• Headphones. Headphones may contain a magnetic substance that can interfere with your ICD. Keep your headphones at least 6 inches (about 15 centimeters) from your ICD.
• Magnets. These might affect your ICD, so it’s a good idea to keep magnets at least 6 inches (15 centimeters) from your ICD site.

Devices that pose little or no risk to your ICD include microwave ovens, televisions and remote controls, AM/FM radios, toasters, electric blankets, electric shavers and electric drills, computers, scanners, printers, and GPS devices.

Driving restrictions

If you have an ICD to treat ventricular arrhythmia, driving a vehicle presents a challenge. The combination of arrhythmia and shocks from your ICD can cause fainting, which would be dangerous while you’re driving.

The American Heart Association’s guidelines discourage driving during the first six months after your procedure if your ICD was implanted due to a previous cardiac arrest or ventricular arrhythmia.

If you have no shocks during this period, you’ll likely be able to drive again. But if you then have a shock, with or without fainting, tell your doctor and follow his or her recommendations. In most cases, you’ll be discouraged from driving until you’ve been shock-free for another six months.
If you have an ICD but have no history of life-threatening arrhythmias, you can usually resume driving within a week after your procedure if you’ve had no shocks. Discuss your situation with your doctor.

You usually can’t get a commercial driver’s license if you have an ICD.

Battery life

The lithium battery in your ICD can last up to seven years. The battery will be checked during regular checkups, which should occur about every six months. When the battery is nearly out of power, your old shock generator is replaced with a new one during a minor outpatient procedure.
ICDs and end-of-life issues
If you have an ICD and become terminally ill, your ICD will still deliver shocks if it isn’t deactivated. Turning off your ICD is an easy procedure, and doing so won’t immediately cause your heart to stop. But turning off the device can prevent unwanted shocks and unnecessary suffering.
Talk to your doctor about your wishes. Also talk to family members or another person designated to make medical decisions for you about what you’d like to do in end-of-life care situations.

Non-Invasive Services

Event Recorder

An event monitor is a portable device used to record your heart’s electrical activity when you have symptoms. It records the same information as an electrocardiogram (ECG), but for longer durations of time. Most of these devices can transmit the recorded information directly to your healthcare provider. This allows him or her to analyze the electrical activity of your heart while you are having symptoms.

Normally, a special group of cells begin the electrical signal to start your heartbeat. These cells are in the sinoatrial (SA) node. This node is in the right atrium, the upper right chamber of the heart. The signal quickly travels down the heart’s conducting system on the way to the ventricles, the two lower chambers of the heart. As it travels, the signal triggers nearby parts of the heart to contract. This helps the heart contract in a coordinated way.

ECGs and event monitors are used to help analyze this electrical signaling through the heart. These tests are very helpful in diagnosing a variety of abnormal heart rhythms and medical conditions. A standard ECG only records the heart signal for a few seconds, and it is not portable.

An event monitor is very similar to something called a Holter monitor. This is another portable device used to analyze the heart’s signaling. Holter monitors record continuously, usually for about 24 to 48 hours. An event monitor does not record continuously. Instead, it records when you activate it. Some event monitors will automatically start recording if an abnormal heart rhythm is detected. Event monitors can be worn for a month or longer.

There are two main types of event monitors: symptom event monitors and memory looping monitors. When you activate a symptom event monitor, for the next few minutes, it records the information from the heart’s electrical signal. A memory looping monitor does the same thing. However, it also records the information from a few minutes before the device was activated, so data from before, during and after the symptom will be captured.

What happens while using an event monitor?

In general:

• If you have a cardiac loop monitor, change your sensors as instructed.
• When you have a symptom, push the button to start recording. (Some start recording automatically when an abnormal rhythm is detected.)
• After you do this, stop moving. This will help the device get a good recording. The device should record for several minutes.
• For some event monitors, you will need to send your recordings over the phone to your healthcare provider.
• Someone will review your recording. In some cases, you may need to go see your healthcare provider.
• Follow all instructions about exercise. Sweat can make the sensors come off.
• If you can, avoid items that can disrupt the event monitor. These include magnets, metal detectors, microwave ovens, electric blankets, electric razors, electric toothbrushes, cell phones, and iPods. You will receive specific instruction at the time the monitor is placed.
• When you need to use an electronic device, keep it at least 6 inches away from the monitor.

You will also need to keep a diary while using your event monitor. Record any symptoms when they happened, and note what you were doing at the time. You may need to wear your event monitor for several days or up to a month.

Holter

A Holter monitor is a small, wearable device that keeps track of your heart rhythm. Your doctor may want you to wear a Holter monitor for one to two days. During that time, the device records all of your heartbeats.

A Holter monitor test is usually performed after a traditional test to check your heart rhythm (electrocardiogram), especially if the electrocardiogram doesn’t give your doctor enough information about your heart’s condition.

Your doctor uses information captured on the Holter monitor to figure out if you have a heart rhythm problem. If standard Holter monitoring doesn’t capture your irregular heartbeat, your doctor may suggest a wireless Holter monitor, which can work for weeks.

Some personal devices, such as smart watches, offer electrocardiogram monitoring. Ask your doctor if this is an option for you.

During Procedure:
A Holter monitor recording is generally done on an outpatient basis. Procedures may vary depending on your condition and your healthcare providers practice.

Generally, a Holter monitor recording follows this process:

• You will be asked to remove any jewelry or other objects that may interfere with the reading.
• You will be asked to remove your clothing from the waist up so that electrodes can be attached to your chest. The technician will ensure your privacy by covering you with a sheet or gown and exposing only the necessary skin.
• The areas where the electrode patches are placed are cleaned, and in some cases, hair may be shaved or clipped so that the electrodes will stick closely to the skin.
• Electrodes will be attached to your chest and abdomen. The Holter monitor will be connected to the electrodes with wires. The small monitor box may be worn over your shoulder like a shoulder bag, around your waist, or it may clip to a belt or pocket.
• Find out if you will have to change the batteries in the monitor. Be sure you know how to do it and have extra batteries on hand.
• Once you have been hooked up to the monitor and given instructions, you can return to your usual activities, such as work, household chores, and exercise, unless your healthcare provider tells you otherwise. This will allow your healthcare provider to identify problems that may only occur with certain activities.
• You will be instructed to keep a diary of your activities while wearing the monitor. Write down the date and time of your activities, particularly if any symptoms, such as dizziness, palpitations, chest pain, or other previously experienced symptoms, occur.

Head-Up Tilt Table

A tilt table test is used to evaluate the cause of unexplained fainting.

Your doctor might recommend a tilt table test if you have repeated, unexplained episodes of lightheadedness, dizziness or fainting. The test can help determine if the cause is related to your heart rate or blood pressure.
Why it’s done
Your doctor might recommend a tilt table test to try to trigger your signs and symptoms — lightheadedness, dizziness or fainting — while your heart rate and blood pressure are being monitored.
Your nervous system controls your heart rate and blood pressure. It may suddenly lower your heart rate and blood pressure for a short time when you’re moved to an upright position during the tilt table test. As a result, less blood flows to your brain, possibly causing you to faint.

Risks

A tilt table test is generally safe, and complications are rare. But, as with any medical procedure, it does carry some risk.

Potential complications include:

• Nausea and vomiting after fainting
• Weakness that can last several hours
• Prolonged low blood pressure after the test
• These complications usually go away when the table is returned to a horizontal position.

How you prepare

You might be asked not to eat or drink for two hours or more before a tilt table test. You can take your medications as usual, unless your doctor tells you otherwise.

What you can expect

To prepare you for the test, a member of your health care team will:

• Have you lie flat on a table that has a footboard and place straps around you to hold you in place.
• Place sticky patches (electrodes) on your chest, legs and arms. Wires connect the electrodes to an electrocardiogram machine that monitors your heart rate.
• Place a blood pressure monitor or cuff on your finger, on your arm or on both to check your blood pressure during the test.
• Place an IV line into a vein in your arm for delivering medication, if needed.
  During a tilt table test
• You’ll start by lying flat on your back on the motorized table for about five minutes.
• You’ll be moved to a nearly vertical position, where you’ll remain from five to 45 minutes, depending on the reason for the test. While vertical, you’ll be asked to remain as still as possible but to report signs and symptoms such as nausea, sweating, lightheadedness or irregular heartbeats.
• If you don’t faint or have other symptoms after 45 minutes, you might receive the medication isoproterenol (Isuprel) through an IV line in your arm. The medication might prompt the abnormal nervous system reflex that causes you to faint.
• You then remain in the upright position for another 15 to 20 minutes.
  Your heart rate and blood pressure will be monitored in each position to evaluate your body’s cardiovascular response to the change in position.

After a tilt table test

If you faint while vertical, the table will be returned to a horizontal position immediately and you’ll be monitored. Most people regain consciousness almost immediately.

In some cases, if blood pressure and heart rate changes indicate you are about to faint, the table is returned to a horizontal position so that you don’t lose consciousness.

When the test is complete, you can return to your normal activities.

Results

The results of a tilt table test are based on whether you faint during the test and what happens to your blood pressure and heart rate.

The result is positive if your blood pressure decreases and you feel dizziness or faint during the test.

The result is negative if your heart rate increases only slightly, your blood pressure doesn’t drop significantly, and you don’t have signs or symptoms of fainting.

Depending on the results, your doctor might recommend additional tests to exclude other causes of fainting.