Oregon Heart and Vascular Institute - Abnormal Heart Rhythm

ARRHYTHMIA | DISEASES | TESTS AND PROCEDURES | CURATIVE PROCEDURES FOR ABNORMAL HEART RHYTHMS | DEVICE TREATMENT

Arrhythmia

What is arrhythmia?
Arrhythmia — also called abnormal heart rhythm or heart rhythm disorder — is irregular heartbeats, heart rates, or rhythms. Your heart is a powerful muscle that pumps a continuous supply of blood, oxygen, and other nutrients through the body. To accomplish this task, your heart needs to regulate the timing of its beats, or rhythm. Your heart’s electrical system controls the rhythm.

Abnormal heart rhythms fall into two general types: extremely slow heart rates — called bradyarrhythmias or bradycardias — and extremely rapid heart rates — called tachyarrhythmias or tachycardias.

At some time in life, most adults experience a racing heart, an extra heartbeat, or a skipped beat. Many of these rhythm changes are passing and harmless. Certain arrhythmias, however, especially those that last long enough to affect the function of the heart, are serious and can be fatal. A serious arrhythmia may be a sign of coronary artery disease, heart muscle disease, heart valve disease, or other heart problems.

The most common type of arrhythmia is atrial fibrillation. Atrial fibrillation was once thought to be a minor heart rhythm disorder. Research in recent years has shown, however, that the problem can be quite serious and lead to such complication as stroke and heart failure.

What causes arrhythmia?
The direct cause of an abnormal heart rhythm is a breakdown in the heart’s electrical system. This breakdown can be caused by a number of conditions, including:

Heart disease, including coronary artery disease
Certain other diseases, including thyroid disease and anemia
High blood pressure
Fever or infection
Physical or emotional stress
Genetics (family history)

Arrhythmia can also be brought on by a host of substances, especially stimulants, including:

Caffeine
Tobacco
Alcohol
Cocaine
Amphetamines
Certain prescription and over-the-counter medications, including diet pills
Certain foods and herbs

Sometimes, however, the cause of an abnormal heart rhythm cannot be accurately determined.

What are the symptoms of arrhythmia?
Sometimes there are no symptoms to warn of an arrhythmia. Other times the symptoms are very clear and alarming. Symptoms include:

Palpitation, or a skipped beat, which feels like an extra heartbeat
Fluttering, a feeling of a number of skipped beats in rapid succession
Slow heartbeat, which brings about fatigue, dizziness, near fainting, or fainting
Rapid heartbeat, which can cause shortness of breath, chest pain, dizziness, near fainting, or fainting
Near fainting — known as pre-syncope — where you may experience lightheadedness or dizziness, blurred or tunnel vision, sweating, headache, mental confusion, stomachache, and nausea or vomiting
Fainting — known as syncope — that comes on suddenly without warning

If you experience fainting, especially sudden fainting, see your doctor as soon as possible. In some cases, fainting may be the only warning sign of a serious abnormal heart rhythm.

How can I prevent arrhythmia?
If you have an existing heart condition, you can do the following to keep it from getting worse:

Know the symptoms of arrhythmia. If you notice symptoms, report them to your doctor as soon as possible.
Have regular checkups.
Maintain your treatment program, and take all your medications.
Know the causes of arrhythmia and the factors that increase the risk of arrhythmia.
Learn how the heart works so you can better understand your condition.

If you have a normal, healthy heart, you can do the following to keep it healthy:

Know the risk factors and symptoms of arrhythmia and other heart conditions.
Get treatment for any problems.
Have regular checkups.
Live a heart-healthy life, which includes:

- Stopping smoking and avoiding secondhand smoke
- Maintaining a healthful weight
- Eating a healthful, balanced, low-fat diet
- Limiting or avoiding caffeine, alcohol, and other substances that contribute to abnormal heart rhythm and other heart problems
- Exercising regularly
- Controlling stress

How is arrhythmia diagnosed?
The heart’s electrical system is complex, so diagnosing problems such as arrhythmia requires special equipment and skilled medical professionals.

A diagnosis begins with a thorough examination by your doctor and a look into your medical history and family’s medical history. Your doctor may call for certain tests, including:

Echocardiogram: an ultrasound exam that uses sound waves to evaluate the size, pumping strength, and valves of the heart
Electrocardiogram (EKG): a recording on graph paper of the electrical impulses generated by the heart
Exercise stress test: a test used to assess the effect of stress on the heart brought on by exercise
Holter monitoring: an exam that helps determine how the heart responds to normal activities and heart medications
Event monitoring: measurements of a small, portable recording device that captures fleeting episodes of abnormal heart rhythm for up to a month
Nuclear medicine test: a test that uses low-dose radiation to create images that show blood flow to the heart
Electrophysiology study: a test to determine the characteristics, or specific features, of abnormal heart rhythm

How is arrhythmia treated?
Treatment for arrhythmia depends on the cause and the severity. Options for treatment include changes in lifestyle, medication, a minimally invasive surgical procedures such as cardiac ablation and Mini-Maze, and the implanting of electronic devices such as a pacemaker or an implanted cardioverter defibrillator.

Major surgery is rarely used to treat abnormal heart rhythm. Surgery is more often used to treat other heart problems such as coronary artery disease. Treating other heart problems may reduce the likelihood of abnormal heart rhythm.

ABNORMAL HEART RHYTHM: DISEASES

Atrial Fibrillation

What is atrial fibrillation?
Atrial fibrillation (AF) is a heart condition in which the heart’s two small upper chambers flutter instead of beat properly. (One chamber is known as an atrium; both together are known as the atria.) These chambers receive blood from the veins in the body.

Normally, the blood is pumped out of the atria into other heart chambers called ventricles. The ventricles then pump the blood, which now contains oxygen, to the rest of the body. Between the two sets of chambers (atria and ventricles) are valves that open and close and direct the flow of blood between the chambers.

Problems can arise when abnormal heart rhythms upset the normal exchange of blood between the chambers and the blood is not completely pumped out of the atria. The blood left in the atria can pool and form a clot. This blood clot can leave the heart, travel to the brain, and cause a stroke.

Atrial fibrillation is the most common form of arrhythmia. It affects more than 2 million people each year. The chances of developing atrial fibrillation increase with age.

What causes atrial fibrillation?
The exact causes of AF are not completely known. Congenital heart defects, lung disease, high blood pressure, thyroid disorders, and other health conditions have been linked to AF.

What are the symptoms?
Sometimes there are no symptoms to warn of atrial fibrillation. Other times the symptoms are the same as those found in other types of arrhythmias: heart palpitations or flutterings, heavy sweating, shortness of breath, chest pain, extreme fatigue, dizziness, and fainting.

How is it diagnosed?
A diagnosis begins with a thorough examination by your doctor and a look into your medical history and family’s medical history. Your doctor may call for tests of your heart such as an echocardiogram or electrocardiogram (EKG) or electrophysiology study. If your doctor suspects that a blood clot has traveled from your legs to your lungs (a pulmonary embolus), you may undergo a VQ scan. Your doctor may also test for an overactive thyroid.

How is atrial fibrillation treated?
Treatment is highly individualized and based on the severity and the symptoms. Current treatment options include:

Medications to keep heart rates in the normal range; blood thinners such as Coumadin, which are effective in preventing stroke; or a combination of heart rate control plus blood thinners
Cardioversion, a procedure in which an electrical charge is delivered to the heart so that it beats regularly again, performed in the early stages of AF and usually followed up with a medication regimen
The use of implanted electronic devices such as a pacemaker or an implanted cardioverter defibrillator
Minimally invasive surgical procedures intended to permanently cure atrial fibrillation, include catheter ablation and Mini-Maze.

ABNORMAL HEART RHYTHM: TESTS AND PROCEDURES

Electrophysiology Study

What is an electrophysiology study?
An electrophysiology study — also called an electrophysiology evaluation, an intracardiac electrophysiology study, or EPS — is a test to determine the characteristics, or specific features, of an abnormal heart rhythm. The test is done to see if an arrhythmia does indeed exist or to find the exact location of a known arrhythmia. The test helps your doctor decide the best treatment for an arrhythmia.

Who conducts the test?
A team of medical professionals led by an electrophysiologist conducts the test. An electrophysiologist is a specially trained cardiologist (heart doctor) who studies and treats the heart's electrical system.

How is an electrophysiology study done?
The electrophysiologist makes a small incision in a vein in your neck, arm, or groin and inserts a thin, flexible tube called a catheter. Using real-time X-rays displayed on a video screen for guidance, the electrophysiologist threads the catheter into the heart. Inside the catheter are electrodes connected to a monitor. The electrodes measure electrical activity in the heart, which helps the electrophysiologist establish the severity of the problem and determine the best course for treatment.

You wear a hospital gown. You are given a local anesthetic in the area where the catheter is inserted and, if you need it, medication to help you relax. Most people remain awake during the procedure. If you do fall asleep, the staff will monitor you constantly.

Is it safe?
The procedure is safe and painless. When the electrophysiologist tests the electrical activity of the heart, you may feel your heart beating faster or stronger. You will have to lie still for between 1 and 2 hours, which may make you feel a little uncomfortable and stiff.

As with many nonsurgical procedures, however, complications sometimes do occur. If you have any questions about potential risks or your condition, ask your doctor.

How should I prepare for this test?
You should not eat or drink anything after midnight the night before the procedure. Be sure to tell your doctor what medications you are taking, whether you have any allergies, and if you are pregnant. You should prepare for an overnight stay in the hospital and arrange for someone to take you home.

What can I expect after the test?
You may feel tenderness or soreness at the site where the catheter was inserted. Let your doctor or the nurses know if you are experiencing any bleeding, pain, or unusual symptoms.

After returning home, limit your activity for several days. Avoid physical exertion and strain. Follow your doctor’s instructions. If you notice any complications or unusual symptoms — such as bleeding that does not stop, fever, rapid heartbeat, chest pain, dizziness, or shortness of breath — call your doctor immediately.

CURATIVE PROCEDURES FOR ABNORMAL HEART RHYTHMS:
Catheter Ablation

What is catheter ablation?
Catheter ablation — also called ablation or radiofrequency ablation— is a nonsurgical treatment to correct abnormal heart rhythm, most often extremely rapid heartbeats (tachyarrhythmias). Catheter ablation destroys abnormal tissue in the heart. Destroying the abnormal tissue repairs the heart’s [electrical system], and the heart assumes its normal rhythm.

Who performs the treatment?
A team of medical professionals led by an electrophysiologist performs the treatment. An electrophysiologist is a specially trained cardiologist (heart doctor) who studies and treats the heart’s electrical system.

How is catheter ablation done?
The procedure usually takes place in the Electrophysiology Laboratory, a sterile x-ray room. A member of the team makes a small incision in a vein in your neck or groin and inserts a thin, flexible tube called a catheter. Using real-time X-rays displayed on a video screen for guidance, the electrophysiologist threads the catheter into the heart.

At the tip of the catheter is an electrode. The electrophysiologist directs the tip of the catheter to the exact spot inside the heart where the abnormal tissue is located. High-frequency energy (which is like microwave heat) heats the tip of the catheter. The heat destroys the abnormal tissue. This tissue, then, can no longer generate or conduct the electrical impulses that caused the rapid heartbeats.

You will wear a hospital gown. You will be given a local anesthetic in the area where the catheter is inserted and medication to help you sleep. Most people are asleep during the procedure and do not feel or remember much of it. The staff will monitor you constantly.

Is it safe?
Radiofrequency ablation is a widely used and proven treatment. It has a high rate of success and low rate of risk. It is done under local anesthesia and causes little or no pain or discomfort.

Complications sometimes do occur. The heart or blood vessels could be damaged during the procedure, or blood clots may form. If you have any questions about potential risks or your condition, ask your doctor.

How should I prepare for this treatment?
You should not eat or drink anything after midnight the night before the treatment. Be sure to tell your doctor what medications you are taking, whether you have any allergies, and if you are pregnant. Most patients go home the same day, and you should arrange for someone to take you home.

What can I expect after the treatment?
Unless you are far from home, you will go home the same day. You may feel tenderness or soreness at the site where the catheter was inserted. Let your doctor or the nurses know if you are experiencing any bleeding, pain or unusual symptoms.

After returning home, limit your activity for one day unless told otherwise, and avoid physical exertion and strain. Most patients can resume normal activities two days after the procedure. Follow your doctor’s instructions. If you notice any complications or unusual symptoms — such as bleeding that does not stop, fever, rapid heartbeat, chest pain, dizziness or shortness of breath — call your doctor immediately.

CURATIVE PROCEDURES FOR ABNORMAL HEART RHYTHMS:
Minimally Invasive Surgical Procedure for AF (Mini-Maze)

What is the Mini-Maze procedure?
The Mini-Maze procedure is a relatively new, minimally invasive, surgical technique used to cure atrial fibrillation (AF). Mini-Maze is replacing open-heart surgery in some cases of AF and is an alternative to catheter ablation of AF.

In the Mini-Maze procedure, the cardiac surgeon destroys a small amount of abnormal tissue in the heart that is thought to be the source of the AF. As a result, the destroyed tissue can no longer generate or conduct electrical impulses. The abnormal signal is disrupted, and the heart assumes its normal rhythm.

Who conducts the treatment?
A team of medical professionals, led by a cardiac surgeon and an electrophysiologist, conducts the surgery. The surgeon has special training in arrhythmia surgery. An electrophysiologist is a specially trained cardiologist (heart doctor) who studies and treats the heart’s electrical system.

Close collaboration is important between electrophysiologists and other doctors who treat patients with heart disease. The Heart Rhythm Services medical staff at Oregon Heart & Vascular Institute includes two electrophysiologists

How is Mini-Maze done?
The Mini-Maze procedure uses incisions between the ribs, is performed on the normally-beating heart (avoiding the need for bypass) and makes only one true incision on the heart. The surgeon places a clamp-like tool on the left atrium near the pulmonary veins, and ablation is performed by heating the atrial tissue between the jaws of the clamp, cauterizing the area, much like a [catheter ablation]. The nerves that cause AF are in the area and may be eliminated as well. The surgeon and the electrophysiologist work closely together to ensure that the ablation is complete, and that the overactive nerves are no longer active. In addition, the part of the left atrium (the “appendage”) where most clots form is removed, which may reduce the long-term likelihood of stroke even if AF were to return.

To learn more about the latest procedures around heart arrhythmias, visit www.minimaze.org, a Web site dedicated to the subject of atrial fibrillation and the Mini-Maze and catheter ablation curative techniques.

Is it safe?
Although still a new procedure, Mini-Maze has been proven safe and effective for most people. Unlike open-heart surgery, the Mini-Maze procedure is done without the need for a large incision or the use of the heart-lung machine. The heart is not stopped during the procedure. There is little risk from the radio waves.

How should I prepare for this treatment?
You should not eat or drink anything after midnight the night before the procedure. Be sure to tell your doctor what medications you are taking, whether you have any allergies and if you are pregnant. You should prepare for a four-day stay in the hospital and arrange for someone to take you home.

What happens after the treatment?
You may feel tenderness or soreness at the site where the incision was made. Let your doctor or the nurses know if you are experiencing any bleeding, pain or unusual symptoms. You will remain in the hospital for four or five days while staff monitors your heart and blood pressure.

After returning home, limit your activity for several days. Avoid physical exertion and strain. Follow your doctor’s instructions. If you notice any complications or unusual symptoms — such as bleeding that does not stop, fever, rapid heartbeat, chest pain, dizziness or shortness of breath — call your doctor immediately.

ABNORMAL HEART RHYTHM: DEVICE TREATMENT

Pacemaker Implantation

What is a pacemaker?
A pacemaker is a battery-powered device used to speed up dangerously slow heartbeats. A slow heartbeat can bring on weakness, shortness of breath, confusion, dizziness and, in extreme cases, death.

Although it does not help the rapid heartbeats usually associated with atrial fibrillation (AF), a pacemaker does control the heartbeat, making it regular and normal. Because AF is still present, risk of stroke continues and blood thinners are still needed.

Who implants the pacemaker?
A team of medical professionals led by a cardiologist performs the treatment.
How is the pacemaker implanted?

Implantation is a minor surgical procedure that takes about an hour. You are given a local anesthetic and a mild sedative to help you relax, and you remain awake during the procedure.

The cardiologist makes an incision just below the collarbone. Using real-time X-rays displayed on a video screen for guidance, the surgeon inserts wires into a vein then into the heart. The other ends of the wires are connected to the pacemaker, which is then implanted beneath the skin under the collarbone.

Is it safe?
Pacemaker implantation is safe. But, as with all surgical procedures, complications can occur, including bleeding or infection at the site where the pacemaker is inserted, damage to a vein and perforation of one of the chambers of the heart. Some people feel the pacemaker under the skin, but carrying a pacemaker is painless.

How should I prepare for the implantation?
You should not eat or drink anything after midnight the night before the procedure. Be sure to tell your doctor what medications you are taking, whether you have any allergies and if you are pregnant. You may have to prepare for an overnight hospital stay, although most patients go home the same day.

What can I expect after the pacemaker is implanted?
After the procedure, you may stay in the hospital for a day or two while staff monitors your heart and makes sure there is no bleeding or infection at the site where the pacemaker was implanted.

What happens after I return home?
For about a week after returning home, you should keep the site dry where the pacemaker was implanted and avoid strenuous activity. After a week or so, you should be able to resume your normal activities.

Today’s pacemakers are highly effective. They are not affected by airport metal detectors or by household appliances. However, cell phones, particularly digital cell phones, may interfere with a pacemaker. Always keep your cell phone at least six inches away from your pacemaker. You should also avoid strong magnetic fields. Ask your doctor about safeguards and what to do in an emergency.

You will need to see your doctor for follow-up visits and for checkups of your pacemaker. Follow-up visits and checkups are painless. In some cases, a pacemaker can be checked over the telephone. Your doctor will schedule your visits and checkups.

Cardioverter Defibrillator Implantation

What is cardioverter defibrillator implantation?
Cardioverter defibrillator implantation is a surgical procedure used to correct abnormal heart rhythm. A small electronic device called an implantable cardioverter defibrillator, or ICD, is implanted in the chest. The ICD is connected to one or more places in or on the heart muscle. By sending electrical impulses to the heart, it keeps the heart’s electrical system functioning as it should. It can deliver a life-saving shock to restore normal heart rhythm.

It is usually done for people who have suffered a heart attack or who experience potentially life-threatening arrhythmias in the ventricles, the lower chambers in the heart that pump blood to the body.

Who implants the ICD?
A team of medical professionals, led by an electrophysiologist, performs the treatment. An electrophysiologist is a specially trained cardiologist (heart doctor) who studies and treats the heart’s electrical system.

How is a cardioverter defibrillator implantation done?
The surgery generally takes place in the Electrophysiology Laboratory. You will be heavily sedated and sleep through the procedure, which takes between two and three hours.

Is it safe?
Cardioverter defibrillator implantation has similar risks to any other general surgery: the possibility of infection, bleeding and reaction to anesthesia. Overall, it is a proven and safe surgical procedure.

How should I prepare for the implantation?
You should not eat or drink anything after midnight the night before the surgery. Be sure to tell your doctor what medications you are taking, whether you have any allergies and if you are pregnant. You should prepare for a short stay in the hospital and arrange for someone to take you home. Most patients go home the same day as the procedure, or may stay overnight.

What can I expect after the implantation?
During your hospital stay, your doctor and the nurses will carefully monitor your heart rhythm and make any needed adjustments to your ICD system.
You may at times feel the ICD delivering therapy. Depending on the strength of the dose, you may experience a jolt to the chest, mild pain or discomfort or nothing at all. If you feel an electrical shock, however, you should tell your doctor or the nurses immediately.

What happens after I return home?
After you return home, you should take it easy for several days. Your doctor will tell you when you can resume your normal activities. The incision will be checked in about a week. You will see your doctor for follow-up visits at the office or clinic. Follow-up visits are painless and take about 30 minutes.
You will be safe around cell phones, televisions, computers, microwaves ovens and most other household appliances if they are properly grounded and in good repair. You should, however, avoid strong magnetic fields. Ask your doctor about safeguards and what to do in an emergency.

Call your doctor immediately if feel an electric shock; if your ICD pocket becomes painful, swollen, or red; or if you experience heart flutterings, rapid heartbeat, heavy sweating or dizziness.