Thursday, November 12, 2009

Congenital Heart Defects

What are congenital heart defects?

Congenital (kon-JEN-i-tal) heart defects are problems with the heart's structure that are present at birth. These defects can involve the interior walls of the heart, valves inside the heart, or the arteries and veins that carry blood to the heart or out to the body. Congenital heart defects change the normal flow of blood through the heart.

There are many different types of congenital heart defects. They range from simple defects with no symptoms to complex defects with severe, life-threatening symptoms.

Congenital heart defects are the most common type of birth defect, affecting 8 of every 1,000 newborns. Each year, more than 35,000 babies in the United States are born with congenital heart defects. Most of these defects are simple conditions that are easily fixed or need no treatment.

A small number of babies are born with complex congenital heart defects that need special medical attention soon after birth. Over the past few decades, the diagnosis and treatment of these complex defects has greatly improved.

As a result, almost all children with complex heart defects grow to adulthood and can live active, productive lives because their heart defects have been effectively treated.

Most people with complex heart defects continue to need special heart care throughout their lives. They may need to pay special attention to certain issues that their condition could affect, such as health insurance, employment, pregnancy and contraception, and preventing infection during routine health procedures. Today in the United States, about 1 million adults are living with congenital heart defects.

How the heart works

To understand congenital heart defects, it's helpful to know how the normal heart works.

Your child's heart is a muscle about the size of his or her fist. It works like a pump and beats 100,000 times a day.

The heart has two sides, separated by an inner wall called the septum. The right side of the heart pumps blood to the lungs to pick up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of the heart, and the left side pumps it to the body.

The heart has four chambers and four valves and is connected to various blood vessels. Veins are the blood vessels that carry blood from the body to the heart. Arteries are the blood vessels that carry blood away from the heart to the body.

The illustration shows a cross-section of a healthy heart and its inside structures. The blue arrow shows the direction in which oxygen-poor blood flows from the body to the lungs. The red arrow shows the direction in which oxygen-rich blood flows from the lungs to the rest of the body.












Heart Chambers

The heart has four chambers or "rooms."

  • The atria (AY-tree-uh) are the two upper chambers that collect blood as it comes into the heart.

  • The ventricles (VEN-trih-kuls) are the two lower chambers that pump blood out of the heart to the lungs or other parts of the body.

Heart Valves

Four valves control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart.

  • The tricuspid (tri-CUSS-pid) valve is in the right side of the heart, between the right atrium and the right ventricle.

  • The pulmonary (PULL-mun-ary) valve is in the right side of the heart, between the right ventricle and the entrance to the pulmonary artery, which carries blood to the lungs.

  • The mitral (MI-trul) valve is in the left side of the heart, between the left atrium and the left ventricle.

  • The aortic (ay-OR-tik) valve is in the left side of the heart, between the left ventricle and the entrance to the aorta, the artery that carries blood to the body.

Valves are like doors that open and close. They open to allow blood to flow through to the next chamber or to one of the arteries, and then they shut to keep blood from flowing backward.

When the heart's valves open and close, they make a "lub-DUB" sound that a doctor can hear using a stethoscope.

  • The first sound - the "lub" - is made by the mitral and tricuspid valves closing at the beginning of systole (SIS-toe-lee). Systole is when the ventricles contract, or squeeze, and pump blood out of the heart.

  • The second sound - the "DUB" - is made by the aortic and pulmonary valves closing at beginning of diastole (di-AS-toe-lee). Diastole is when the ventricles relax and fill with blood pumped into them by the atria.

Arteries

The arteries are major blood vessels connected to your heart.

  • The pulmonary artery carries blood pumped from the right side of the heart to the lungs to pick up a fresh supply of oxygen.

  • The aorta is the main artery that carries oxygen-rich blood pumped from the left side of the heart out to the body.

  • The coronary arteries are the other important arteries attached to the heart. They carry oxygen-rich blood from the aorta to the heart muscle, which must have its own blood supply to function.

Veins

The veins are also major blood vessels connected to your heart.

  • The pulmonary veins carry oxygen-rich blood from the lungs to the left side of the heart so it can be pumped out to the body.

  • The vena cava is a large vein that carries oxygen-poor blood from the body back to the heart.

What are the types of congenital heart defects?

Congenital heart defects change the normal flow of blood through the heart because some part of the heart didn't develop properly before birth.

There are many types of congenital heart defects. They include simple ones such as a hole in the interior walls of the heart that allows blood from the left and right sides of the heart to mix, or a narrowed valve that blocks the flow of blood to the lungs or other parts of the body.

Other defects are more complex. These include combinations of simple defects, problems with where the blood vessels leading to and from the heart are located, and more serious abnormalities in how the heart develops.

Examples of Simple Congenital Heart Defects

Holes in the Heart (Septal Defects)

The septum is the wall that separates the chambers on the left side of the heart from those on the right. It prevents mixing of blood between the two sides of the heart. Sometimes, a baby is born with a hole in the septum. When that occurs, blood can mix between the two sides of the heart.

Atrial septal defect (ASD). An ASD is a hole in the part of the septum that separates the atria - the upper chambers of the heart. This heart defect allows oxygen-rich blood from the left atrium to flow into the right atrium instead of flowing to the left ventricle as it should. Many children who have ASDs have few, if any, symptoms.

Normal Heart and Heart With Atrial Septal Defect
Picture of Atrial Septal Defect

Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows a heart with an atrial septal defect, which allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood from the right atrium.

An ASD can be small or large. Small ASDs allow only a little blood to leak from one atrium to the other. Very small ASDs don't affect the way the heart works and therefore don't need any special treatment. Many small ASDs close on their own as the heart grows during childhood. Medium to large ASDs allow more blood to leak from one atrium to the other, and they're less likely to close on their own.

Half of all ASDs close on their own or are so small that no treatment is needed. Medium to large ASDs that need treatment can usually be repaired using a catheter procedure. (See "How Are Congenital Heart Defects Treated?")

Ventricular septal defect (VSD). A VSD is a hole in the part of the septum that separates the ventricles - the lower chambers of the heart. The hole allows oxygen rich blood to flow from the left ventricle into the right ventricle instead of flowing into the aorta and out to the body as it should.

Normal Heart and Heart With Ventricular Septal Defect
Picture of Ventricular Septal Defect

Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows two common locations for a ventricular septal defect. The defect allows oxygen-rich blood from the left ventricle to mix with oxygen-poor blood in the right ventricle.

A VSD can be small or large. A small VSD doesn't cause problems and may often close on its own. Large VSDs cause the left side of the heart to work too hard and increase blood pressure in the right side of the heart and the lungs because of the extra blood flow. The increased work of the heart can cause heart failure and poor growth. If the hole isn't closed, the high blood pressure in the lungs can cause the delicate arteries in the lungs to scar, a condition called pulmonary arterial hypertension. Open-heart surgery is used to repair VSDs.

Narrowed Valves

Simple congenital heart defects also can involve the heart's valves, which control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart (the aorta and the pulmonary artery). Valves can have the following types of defects:

  • Stenosis. This is when the valve doesn't open completely, and the heart has to work harder to pump the blood through the valve.

  • Atresia. This is when the valve doesn't form correctly, so there is no opening for blood to pass through.

  • Regurgitation (re-GUR-ji-TA-shun). This is when the valve doesn't close completely, so blood leaks back through the valve.

The most common valve defect is called pulmonary valve stenosis, which is a narrowing of the pulmonary valve. This valve allows blood to flow from the right ventricle into the pulmonary arteries and out to the lungs to pick up oxygen.

Pulmonary valve stenosis can range from mild to severe. Most children with this defect have no signs or symptoms other than a heart murmur. Treatment isn't needed if the stenosis is mild.

In a baby with severe pulmonary valve stenosis, the right ventricle can get very overworked trying to pump blood to the pulmonary arteries. Oxygen-poor blood can back up from the right side of the heart into the left side, causing cyanosis. Cyanosis is a bluish tint to the skin, lips, and fingernails. It occurs because the oxygen level in the blood leaving the heart is below normal.

Older children with severe pulmonary valve stenosis may have symptoms such as fatigue (tiredness) when exercising. Severe pulmonary valve stenosis is treated with a catheter procedure.

Example of a Complex Congenital Heart Defect

Complex congenital heart defects need to be repaired with surgery. Because of advances in diagnosis and treatment, doctors can now successfully repair even very complex congenital heart defects.

The most common complex heart defect is tetralogy of Fallot (teh-TRALL-o-gee of fall-O), a combination of four defects:

  • Pulmonary valve stenosis.

  • A large VSD.

  • An overriding aorta. The aorta sits above both the left and right ventricles over the VSD, rather than just over the left ventricle. As a result, oxygen poor blood from the right ventricle can flow directly into the aorta instead of into the pulmonary artery to the lungs.

  • Right ventricular hypertrophy. The muscle of the right ventricle is thicker than usual because of having to work harder than normal.

These defects prevent enough blood from flowing to the lungs to get oxygen, while oxygen-poor blood flows directly out to the body.

Normal Heart and Heart With Tetralogy of Fallot
Picture of Tetrology Fallot Heart Defect

Figure A shows the normal structure and blood flow in the interior of the heart. Figure B shows a heart with the four defects of tetralogy of Fallot.

Babies and children with tetralogy of Fallot have episodes of cyanosis, which can sometimes be severe. In the past, when this condition wasn't treated in infancy, older children would get very tired during exercise and could have fainting spells. Tetralogy of Fallot is now repaired in infancy to prevent these types of symptoms.

Tetralogy of Fallot must be repaired with open heart surgery, either soon after birth or later in infancy, depending on how severely the pulmonary artery is narrowed. Children who have had this heart defect repaired need lifelong medical care from a specialist to make sure they stay as healthy as possible.

What are other names for congenital heart defects?

  • Congenital heart disease

  • Cyanotic heart disease

  • Heart defects

  • Congenital cardiovascular malformations

What causes congenital heart defects?

If you have a child with a congenital heart defect, you may think you did something wrong during your pregnancy to cause the problem. However, most of the time doctors don't know why congenital heart defects develop.

Heredity may play a role in some heart defects. For example, a parent who has a congenital heart defect may be more likely than other people to have a child with the condition. In rare cases, more than one child in a family is born with a heart defect. Children with genetic defects often have congenital heart defects. An example of this is Down syndrome - half of all babies with Down syndrome have congenital heart defects.

Scientists continue to search for the causes of congenital heart defects.

What are the signs and symptoms and signs of congenital heart defects?

Many congenital heart defects have few or no symptoms. A doctor may not even detect signs of a heart defect during a physical exam.

Some heart defects do have symptoms. These depend on the number and type of defects and how severe the defects are. Severe defects can cause symptoms, usually in newborn babies. These symptoms can include:

  • Rapid breathing

  • Cyanosis (a bluish tint to the skin, lips, and fingernails)

  • Fatigue (tiredness)

  • Poor blood circulation

Congenital heart defects don't cause chest pain or other painful symptoms.

Abnormal blood flow through the heart caused by a heart defect will make a certain sound. Your doctor can hear this sound, called a heart murmur, with a stethoscope. However, not all murmurs are a sign of a congenital heart defect. Many healthy children have heart murmurs.

Normal growth and development depend on a normal workload for the heart and normal flow of oxygen-rich blood to all parts of the body. Babies with congenital heart defects may have cyanosis or tire easily when feeding. Sometimes they have both problems. As a result, they may not gain weight or grow as they should.

Older children may get tired easily or short of breath during exercise or activity. Many types of congenital heart defects cause the heart to work harder than it should. In severe defects, this can lead to heart failure, a condition in which the heart can't pump blood strongly throughout the body. Symptoms of heart failure include:

  • Fatigue with exercise

  • Shortness of breath

  • A buildup of blood and fluid in the lungs

  • A buildup of fluid in the feet, ankles, and legs

How are congenital heart defects diagnosed?

Serious congenital heart defects are generally identified during pregnancy or soon after birth. Less severe defects aren't diagnosed until children are older. Minor defects often have no symptoms and are diagnosed based on results from a physical exam and special tests done for another reason.

Specialists Involved

Doctors who specialize in the care of babies and children who have heart problems are called pediatric cardiologists. Other specialists who treat heart defects in children include cardiac surgeons (doctors who repair heart defects using surgery).

Physical Exam

  • During a physical exam, the doctor:

  • Listens to your child's heart and lungs with a stethoscope

Looks for other signs of a heart defect, such as cyanosis (a bluish tint to the skin, lips, or fingernails), shortness of breath, rapid breathing, delayed growth, or signs of heart failure

Tests Commonly Used To Diagnosis Congenital Heart Defects

Echocardiogram

This test, which is harmless and painless, uses sound waves to create a moving picture of your child's heart. During an echocardiogram, reflected sound waves show the structure of the heart. The test allows the doctor to clearly see any problem with the way the heart is formed or the way it's working.

An echocardiogram is an important test for both diagnosing a heart problem and following the problem over time. In children with congenital heart defects, an echocardiogram will outline the problems with the heart's structure and show how the heart is reacting to these problems. The echocardiogram will help your child's cardiologist decide if and when treatment is needed.

During pregnancy, if your doctor suspects that your baby has a congenital heart defect, a special test called a fetal echocardiogram can be done. This test uses sound waves to create a picture of the baby's heart while the baby is still in the womb. The test is usually done during the fourth or fifth month of pregnancy. If your child is diagnosed with a congenital heart defect before birth, your doctor can plan treatment before the baby is born.

EKG (Electrocardiogram)

An EKG detects and records the electrical activity of the heart. An EKG shows how fast the heart is beating and whether the heart's rhythm is steady or irregular. It can also detect if one of the heart's chambers is enlarged, which can help diagnose a heart problem.

Chest X Ray

A chest x ray takes a picture of the heart and lungs. It can show whether the heart is enlarged or whether the lungs have extra blood or fluid, which can be a sign of heart failure.

Pulse Oximetry

Pulse oximetry shows how much oxygen is in the blood. A sensor is placed on the child's fingertip or toe (like an adhesive bandage). The sensor is attached to a small computer unit, which displays a number that indicates how much oxygen is in the blood.

Cardiac Catheterization

During cardiac catheterization (KATH-e-ter-i-ZA-shun), a thin, flexible tube called a catheter is passed through a vein in the arm, groin (upper thigh), or neck to reach the heart. A dye that can be seen on an x ray is injected through the catheter into a blood vessel or a chamber of the heart. This allows the doctor to see the flow of blood through the heart and blood vessels.

Cardiac catheterization also can be used to measure the pressure inside the heart and blood vessels and to determine whether blood is mixing between the two sides of the heart. It's also used to repair some heart defects.

How are congenital heart defects treated?

Although many children with congenital heart defects don't need treatment, some do. Doctors treat congenital heart defects with:

  • Procedures using catheters to repair the defect

  • Surgery to repair the defect

The treatment your child receives depends on the type and severity of his or her heart defect. Other factors include your child's age, size, and general health. Treatment can be simple or very complex. Some children with complex congenital heart defects may need several catheter or surgical procedures over a period of years, or may need to take medicines for years.

Procedures Using Catheters

Catheter procedures are much easier than surgery on patients because they involve only a needle puncture in the skin where the catheter is inserted into a vein or an artery. Doctors don't have to surgically open the chest or operate directly on the heart to repair the defect. This means that recovery can be much easier and quicker.

The use of catheter procedures has grown a lot in the past 20 years. They have become the preferred way to repair many simple heart defects, such as:

  • Atrial septal defect. The doctor inserts the catheter through a vein and threads it up into the heart to the septum. The catheter has a tiny umbrella‑like device folded up inside it. When the catheter reaches the septum, the device is pushed out of the catheter and positioned so that it plugs the hole between the atria. The device is secured in place and the catheter is then withdrawn from the body.

  • Pulmonary valve stenosis. The doctor inserts the catheter through a vein and threads it into the heart to the pulmonary valve. A tiny balloon at the end of the catheter is quickly inflated to push apart the leaflets, or "doors," of the valve. The balloon is then deflated and the catheter is withdrawn. Procedures like this can be used to repair any narrowed valve in the heart.

Doctors often use an echocardiogram or a transesophageal (trans-e-SOF-ah-ge-al) echocardiogram (TEE) as well as an angiogram to guide them in threading the catheter and doing the repair. A TEE is a special type of echocardiogram that takes pictures of the back of the heart through the esophagus (the tube leading from the mouth to the stomach). TEE also is often used to define complex heart defects.

Catheter procedures also are sometimes used during surgery to help repair complex defects.

Surgery

A child may need open-heart surgery if his or her heart defect can't be fixed using a catheter procedure. Sometimes, one surgery can repair the defect completely. If that's not possible, a child may need more than one surgery over a period of months or years to fix the problem.

Open-heart surgery may be done to:
  • Close holes in the heart with stitches or with a patch

  • Repair or replace heart valves

  • Widen arteries or openings to heart valves

  • Repair complex defects, such as problems with where the blood vessels near the heart are located and how they develop

Rarely, babies are born with multiple defects that are too complex to repair. These babies may need a heart transplant. In this procedure, the child's heart is replaced with a healthy heart from a deceased child that has been donated by that child's family.

Living with a congenital heart defect

The outlook for a child with a congenital heart defect is much better today than in past years. Advances in testing and treatment mean that most children with heart defects grow into adulthood and are able to live active, productive lives. Many need no special care or only occasional checkups with a cardiologist as they grow up and go through adult life.

The small number of children who have complex heart defects need long-term, special care by trained specialists to stay as healthy as possible and maintain a good quality of life.

Children and Teens With Congenital Heart Defects

Routine Medical Care

Ongoing medical care is important for your child's health. This includes:

  • Checkups with your child's heart specialist as directed

  • Checkups with your child's pediatrician or family doctor for routine exams


  • Taking medicines as prescribed

Most children with severe heart defects are at increased risk for bacterial endocarditis, a serious infection of the heart valves or lining of the heart. Your child's doctor or dentist may give your child antibiotics before medical or dental procedures (such as surgery or dental cleanings) that could allow bacteria into the bloodstream. Talk to your child's doctor about whether your child needs to take antibiotics before such procedures.

As children with heart defects grow up and become teens, it's important that they understand what kind of defect they have, how it was treated, and what kind of care may still be needed. This understanding will help the teen take responsibility for his or her health. It also will help ensure a smooth transition from care by a pediatric cardiologist to care by an adult cardiologist. Young adults with complex congenital heart defects require ongoing care by doctors who specialize in adult congenital heart defects.

You may want to work with your health care providers to put together a packet with medical records and information that covers all aspects of your child's heart defect, including:

  • Diagnosis

  • Procedures or surgeries

  • Prescribed medicines

  • Recommendations about medical followup and how to prevent complications

  • Health insurance

Keeping your health insurance current is important. For example, if your child is covered under health insurance through your employer and you plan to change jobs, find out if health insurance through your new employer will cover care for your child's congenital heart defect. Some health insurance plans may not cover medical conditions that you or your family member had before joining the new plan.

It's also very important for your child to have health insurance as adulthood approaches. Review your current health insurance plan. Find out how coverage can be extended to your child beyond the age of 18. Some policies may allow you to keep your child on your plan if he or she remains in school or is disabled.

Feeding and Nutrition

Some babies and children with congenital heart defects don't grow and develop as fast as other children who are the same age. If your child's heart has to pump harder than normal because of the defect, he or she may tire quickly when feeding or eating and not be able to eat enough.

As a result, your child may be smaller and thinner than other children. Your child also may start activities such as rolling over, sitting, and walking later than other children. After treatments and surgery, growth and development often improve.

To help your baby get enough calories, discuss with his or her doctor the best feeding schedule and any supplements your baby may need. Make sure your child has nutritious meals and snacks as he or she grows to help with growth and development.

Exercise and Physical Activity

Exercise helps children strengthen their muscles and stay healthy. Discuss with your child's doctor how much and what kinds of physical activities are best for your child. Some children and teens with congenital heart defects may need to limit the amount or type of exercise they do.

Remember to ask the doctor for a note for school and other organizations describing any limits on your child's exercise or physical activities.

Emotional Issues

It's common for children and teens with serious conditions or illnesses to have a hard time emotionally or to feel isolated if they have to be in the hospital a lot. Some feel sad or frustrated with their body image and their inability to be a "normal" kid. Sometimes brothers or sisters are jealous of a child who needs a lot of attention for medical problems.

If you have concerns about your child's emotional health, talk to his or her doctor.

Adults With Congenital Heart Defects

Adults with congenital heart defects who needed regular medical checkups in their youth may need to keep seeing a specialist who can care for their health. They will need to pay attention to the following issues.

Medical History

Sometimes people mistakenly believe that the surgery they had in childhood for their congenital heart defect was a "cure." They don't realize that regular medical followup may be needed in adulthood to maintain good health.

Some adults may not know what kind of heart defect they had (or still have) or how it was repaired. They should learn about their medical history and know as much as possible about any medicines they're taking.

Preventing Bacterial Endocarditis

Some people may need antibiotics before medical or dental procedures that could allow bacteria to enter the bloodstream. Talk to your doctor about whether you need to take antibiotics before such procedures. Regular brushing, flossing, and visits to the dentist also can help prevent bacterial endocarditis.

Contraception and Pregnancy

Women who have heart defects should talk with their doctors about the safest type of birth control. Many women can safely use most methods, but some women should avoid certain types of birth control, such as birth control pills or intrauterine devices (IUDs).

Many women with simple heart defects can have a normal pregnancy and delivery. Women with congenital heart defects who want to become pregnant (or who are pregnant) should talk with their doctor about the health risks. They also may want to consult with specialists who help pregnant women with congenital heart defects.

Health Insurance and Employment

When thinking about changing jobs, adults with congenital heart defects should carefully consider the impact on their health insurance coverage. Some health plans have waiting periods or clauses to exclude some kinds of coverage. Before making any job changes, find out whether the change will affect your health insurance coverage.

Several laws protect the employment rights of people who have congenital heart defects. The Americans with Disabilities Act and the Work Incentives Improvement Act try to ensure fairness in hiring for all people, including those with health conditions such as heart defects.

Congenital Heart Disease At A Glance
  • Congenital heart defects are problems with the heart's structure that are present at birth. Congenital heart defects change the normal flow of blood through the heart.

  • Congenital heart defects are the most common type of birth defect, affecting 8 out of every 1,000 newborns. Each year, more than 35,000 babies in the United States are born with congenital heart defects.

  • There are many types of congenital heart defects ranging from simple to very complex.

  • Doctors don't know what causes most congenital heart defects. Heredity may play a role.

  • Although many heart defects have few or no symptoms, some do. Severe defects can cause symptoms such as:

    • Rapid breathing.

    • A bluish tint to skin, lips, and fingernails. This is called cyanosis.

    • Fatigue (tiredness).

    • Poor blood circulation.

  • Serious heart defects are usually diagnosed while a baby is still in the womb or soon after birth. Some defects aren't diagnosed until later in childhood, or even in adulthood.

  • An echocardiogram is an important test for both diagnosing a heart problem and following the problem over time. This test helps diagnose problems with how the heart is formed and how well it's working. Other tests include EKG (electrocardiogram), chest x ray, pulse oximetry, and cardiac catheterization.

  • Doctors treat congenital heart defects with catheter procedures and surgery.

  • Treatment depends on the type and severity of the defect.

  • With new advances in testing and treatment, most children with congenital heart defects grow into adulthood and can live healthy, productive lives. Some need special care all though their lives to maintain a good quality of life

Sunday, November 1, 2009

Mitral Valve Prolapse

What is mitral valve prolapse?

Mitral valve prolapse (also known as "click murmur syndrome" and "Barlow's syndrome") is the most common heart valve abnormality, affecting five to ten percent of the world population. A normal mitral valve consists of two thin leaflets, located between the left atrium and the left ventricle of the heart. Mitral valve leaflets, shaped like parachutes, are attached to the inner wall of the left ventricle by a series of strings called "chordae." When the ventricles contract, the mitral valve leaflets close snugly and prevent the backflow of blood from the left ventricle into the left atrium. When the ventricles relax, the valves open to allow oxygenated blood from the lungs to fill the left ventricle.

In patients with mitral valve prolapse, the mitral apparatus (valve leaflets and chordae) becomes affected by a process called myxomatous degeneration. In myxomatous degeneration, the structural protein collagen forms abnormally and causes thickening, enlargement, and redundancy of the leaflets and chordae. When the ventricles contract, the redundant leaflets prolapse (flop backwards) into the left atrium, sometimes allowing leakage of blood through the valve opening (mitral regurgitation). When severe, mitral regurgitation can lead to heart failure and abnormal heart rhythms. Most patients are totally unaware of the prolapsing of the mitral valve. Others may experience a number of symptoms discussed below.

The mitral valve prolapse (MVP) syndrome has a strong hereditary tendency, although the exact cause is unknown. Affected family members are often tall, thin, with long arms and fingers, and straight backs. It is seen most commonly in women from 20 to 40 years old, but also occurs in men.

Heart and Valves Illustration

What are the signs and symptoms of mitral valve prolapse?

Most people with mitral valve prolapse have no symptoms, however, those who do commonly complain of symptoms such as fatigue, palpitations, chest pain, anxiety, and migraine headaches. Stroke is a very rare complication of mitral valve prolapse.

Fatigue is the most common complaint, although the reason for fatigue is not understood. Patients with mitral valve prolapse may have imbalances in their autonomic nervous system, which regulates heart rate and breathing. Such imbalances may cause inadequate blood oxygen delivery to the working muscles during exercise, thereby causing fatigue.

Palpitations are sensations of fast or irregular heart beats. In most patients with mitral valve prolapse, palpitations are harmless. In very rare cases, potentially serious heart rhythm abnormalities may underlie palpitations which require further evaluation and treatment.

Sharp chest pains are reported in some patients with mitral valve prolapse, which can be prolonged. Unlike angina, chest pain with mitral valve prolapse rarely occurs during or after exercise, and may not respond to nitroglycerin.

Anxiety, panic attacks, and depression may be associated with mitral valve prolapse. Like fatigue, these symptoms are believed to be related to imbalances of the autonomic nervous system.

Migraine headaches have been occasionally linked to mitral valve prolapse. They are probably related to abnormal nervous system control of the tension in the blood vessels in the brain.

Mitral valve prolapse may be rarely associated with strokes occurring in young patients. These patients appear to have increased blood clotting tendencies due to abnormally sticky blood clotting elements, called platelets.

How is mitral valve prolapse diagnosed and evaluated?

Examination of the patient reveals characteristic findings unique to mitral valve prolapse. Using a stethoscope, a clicking sound is heard soon after the ventricle begins to contract. This clicking is felt to reflect tightening of the abnormal valve leaflets against the pressure load of the left ventricle. If there is associated leakage (regurgitation) of blood through the abnormal valve opening, a "whooshing" sound (murmur) can be heard immediately following the clicking sound.

Echocardiography (ultrasound imaging of the heart) is the most useful test for mitral valve prolapse. Echocardiography can measure the severity of prolapse and the degree of mitral regurgitation. It can also detect areas of infection on the abnormal valves. Valve infection is called endocarditis and is a very rare, but potentially serious complication of mitral valve prolapse. Echocardiography can also evaluate the effect of prolapse and regurgitation on the functioning of the muscles of the ventricles.

Abnormally rapid or irregular heart rhythms can occur in patients with mitral valve prolapse, causing palpitations. A 24-hour Holter monitor is a continuous cassette recording of the patient's heart rhythm as the patient carries on his/her daily activities. Abnormal rhythms occurring during the test period are captured on tape and analyzed at a later date. If abnormal rhythms do not occur every day, the Holter recording may fail to capture the abnormal rhythms. These patients then can be fitted with a small "event-recorder" to be worn for up to several weeks. When the patient senses a palpitation, an event button can be pressed to record the heart rhythm prior to, during, and after the palpitations.

What is the treatment for mitral valve prolapse?

The vast majority of patients with mitral valve prolapse have an excellent prognosis and need no treatment. For these individuals, routine examinations including echocardiograms every few years may suffice. Mitral regurgitation in patients with mitral valve prolapse can lead to heart failure, heart enlargement, and abnormal rhythms. Therefore, mitral valve prolapse patients with mitral regurgitation are often evaluated annually. Since valve infection, endocarditis, is a rare, but potentially serious complication of mitral valve prolapse, patients with mitral valve prolapse are usually given antibiotics prior to any procedure which can introduce bacteria into the bloodstream. These procedures include routine dental work, minor surgery, and procedures that can traumatize body tissues such as colonoscopy, gynecologic, or urologic examinations. Examples of antibiotics used include oral amoxicillin and erythromycin as well as intramuscular or intravenous ampicillin, gentamycin, and vancomycin.

Patients with severe prolapse, abnormal heart rhythms, fainting spells, significant palpitations, chest pain, and anxiety attacks may need treatment. Beta-blockers, such as atenolol (Tenormin), metoprolol (Lopressor), and propranolol (Inderal), are the drugs of choice. These act by increasing the size of the left ventricle, thereby reducing the degree of prolapse. The calcium blockers verapamil (Calan) and diltiazem (Cardizem) are useful in patients who cannot tolerate beta-blockers.

Although most patients with mitral valve prolapse require no treatment or treatment with oral medications, in very rare cases, surgery (mitral valve replacement or repair) may be required. Patients who require surgery usually have severe mitral regurgitation causing worsening heart failure and progressive heart enlargement. Rarely, rupture of one or more chordae can cause sudden, severe mitral regurgitation and heart failure requiring surgical repair. Mitral valve repair is preferable if possible, to mitral valve replacement as the surgical treatment for mitral valve regurgitation. After mitral valve replacement, lifelong blood thinning medications are necessary to prevent blood from clotting on the artificial valves. After mitral valve repair, these blood thinning medications are unnecessary. Because of the success of valve repair, it is being performed earlier in patients with mitral regurgitation, thus reducing the risk of abnormal heart rhythms and heart failure.

Rare patients with mitral valve prolapse may suffer strokes because of increased blood clotting. These patients can be treated with a combination of a blood thinner (anticoagulant) and a beta-blocker.

Again, although patients with mitral valve prolapse may experience a variety of complications, most have no symptoms and can lead healthy, active, and normal lives.

Mitral Valve Prolapse At A Glance
  • Mitral valve prolapse (mitral valve prolapse) is the most common heart valve abnormality.
  • Most patients with mitral valve prolapse have no symptoms and require no treatment.
  • Mitral valve prolapse can be associated with fatigue and/or palpitations.
  • Mitral valve prolapse can often be detected by a doctor during examination of the heart. mitral valve prolapse can be confirmed with an echocardiogram.
  • Patients with mitral valve prolapse are usually given antibiotics prior to any procedure which might introduce bacteria into the bloodstream, including dental work and minor surgery.


Wednesday, October 14, 2009

Coronary Artery Disease

Your heart is an amazing powerhouse that pumps and circulates 5 or 6 gallons of blood each minute through your entire body.

Your heart is an amazing powerhouse that pumps and circulates 5 or 6 gallons of blood each minute through your entire body.


Saturday, October 10, 2009

angina

Introduction to angina

Chest pain is a common symptom that is caused by many different conditions. Some causes require prompt medical attention, such as angina, heart attack, or tearing of the aorta. Other causes of chest pain that may not require immediate medical intervention include spasm of the esophagus, gallbladder attack, or inflammation of the chest wall. An accurate diagnosis is important in providing proper treatment to patients with chest pain.

The diagnosis and treatment of angina is discussed below, as well as the diagnosis of other causes of chest pain that can mimic angina.

What is angina, and what are the symptoms of angina?

Angina (angina pectoris - Latin for squeezing of the chest) is chest discomfort that occurs when there is a decreased blood oxygen supply to an area of the heart muscle. In most cases, the lack of blood supply is due to a narrowing of the coronary arteries as a result of arteriosclerosis.

Angina is usually felt as:

  • pressure,
  • heaviness,
  • tightening,
  • squeezing, or
  • aching across the chest, particularly behind the breastbone.

This pain often radiates to the neck, jaw, arms, back, or even the teeth.

Patients may also suffer:

Angina usually occurs during exertion, severe emotional stress, or after a heavy meal. During these periods, the heart muscle demands more blood oxygen than the narrowed coronary arteries can deliver. Angina typically lasts from 1 to 15 minutes and is relieved by rest or by placing a nitroglycerin tablet under the tongue. Nitroglycerin relaxes the blood vessels and lowers blood pressure. Both rest and nitroglycerin decrease the heart muscles demand for oxygen, thus relieving angina.

Angina is classified in one of two types: 1) stable angina or 2) unstable angina.

Stable angina

Stable angina is the most common type of angina, and what most people mean when they refer to angina. People with stable angina have angina symptoms on a regular basis and the symptoms are somewhat predictable (for example, walking up a flight of steps causes chest pain). For most patients, symptoms occur during exertion and commonly last less than five minutes. They are relieved by rest or medication, such as nitroglycerin under the tongue.

Unstable angina

Unstable angina is less common and more serious. The symptoms are more severe and less predictable than the pattern of stable angina. Moreover, the pains are more frequent, last longer, occur at rest, and are not relieved by nitroglycerin under the tongue (or the patient needs to use more nitroglycerin than usual). Unstable angina is not the same as a heart attack, but it warrants an immediate visit to your healthcare provider or hospital emergency department as further cardiac testing is urgently needed. Unstable angina is often a precursor to a heart attack.

What causes angina?

The most common cause of angina is coronary artery disease. A less common cause of angina is spasm of the coronary arteries.

Coronary artery disease

Coronary arteries supply oxygenated blood to the heart muscle. Coronary artery disease develops as cholesterol is deposited in the artery wall, causing the formation of a hard, thick substance called cholesterol plaque. The accumulation of cholesterol plaque over time causes narrowing of the coronary arteries, a process called arteriosclerosis. Arteriosclerosis can be accelerated by smoking, high blood pressure, elevated cholesterol, and diabetes. When coronary arteries become narrowed by more than 50% to 70%, they can no longer meet the increased blood oxygen demand by the heart muscle during exercise or stress. Lack of oxygen to the heart muscle causes chest pain (angina).

Coronary artery spasm

The walls of the arteries are surrounded by muscle fibers. Rapid contraction of these muscle fibers causes a sudden narrowing (spasm) of the arteries. A spasm of the coronary arteries reduces blood to the heart muscle and causes angina. Angina as a result of a coronary artery spasm is called "variant" angina or Prinzmetal angina. Prinzmetal angina typically occurs at rest, usually in the early morning hours. Spasms can occur in normal coronary arteries as well as in those narrowed by arteriosclerosis.

Coronary artery spasm can also be caused by use/abuse of cocaine. The spasm of the artery wall caused by cocaine can be so significant that it can actually cause a heart attack.

What are other causes of chest pain?

In caring for patients with chest pain, the doctor distinguishes whether the pain is related to a lack of oxygen to the heart muscle (as in angina or heart attack), or is due to another process. Many conditions are considered that can cause chest pain which is similar to that of a heart attack or angina. Examples include the following:

  • Pleuritis (pleurisy): Inflammation of the lining of the lungs (pleuritis) causes sharp chest pain, which is aggravated by deep breathing and coughing. Patients often notice shortness of breath, in part due to their shallow breathing to minimize chest pain. Viral infections are the most common causes of pleurisy. Other systemic inflammatory conditions, such as systemic lupus, can also cause pleurisy.
  • Pericarditis: Pericarditis is inflammation of the lining around the heart. Symptoms of pericarditis are similar to that of pleuritis.
  • Pneumonia: Pneumonia (bacterial infection of the lung) causes fever and chest pain. Chest pain in bacterial pneumonia is due to an irritation or infection of the lining of the lung (pleura).
  • Pulmonary embolism: blood clots travel from the veins of the pelvis or the lower extremities to the lung, the condition is called pulmonary embolism. Pulmonary embolism can cause death of lung tissue (pulmonary infarction). Pulmonary infarction can lead to irritation of the pleura, causing chest pain similar to pleurisy. Some common causes of blood clots in these veins is deep vein thrombosis (prolonged immobility, recent surgery, trauma to the legs, or pelvic infection).
  • Pneumothorax: Small sacs in the lung tissue (alveoli) can spontaneously burst, causing pneumothorax. Symptoms of pneumothorax include sudden, severe, sharp chest pain and shortness of breath. One common cause of pneumothorax is severe emphysema.
  • Mitral valve prolapse: Mitral valve prolapse is a common heart valve abnormality, affecting 5% to 10% of the population. MVP is especially common among women between 20 to 40 years of age. Chest pain with MVP is usually sharp but not severe. Unlike angina, chest pain with MVP rarely occurs during or after exercise, and usually will not respond to nitroglycerin.
  • Aortic dissection: The aorta is the major vessel delivering blood from the left ventricle to the rest of the body. Aortic dissection (tearing of the aorta wall) is a life-threatening emergency. Aortic dissection causes severe, unrelenting chest and back pain. Young adults with aortic dissection usually have Marfan's syndrome, an inherited disease in which an abnormal form of the structural protein called collagen causes weakness of the aortic wall. Older patients develop aortic dissection typically as a result of chronic, high blood pressure, in addition to generalized hardening of the arteries (arteriosclerosis).
  • Costochondritis, rib fractures, muscle strain or spasm: Pain originating from the chest wall may be due to muscle strain or spasm, costochondritis, or rib fractures. Chest wall pain is usually sharp and constant. It is usually worsened by movement, coughing, deep breathing, and direct pressure on the area. Muscle spasm and strain can result from vigorous, unusual twisting and bending. The joints between the ribs and cartilage next to the breastbone can become inflamed, a condition called costochondritis. Fractured ribs resulting from trauma or cancer involvement can cause significant chest pain.
  • Nerve compression: Compression of the nerve roots by bone spurs as they exit the spinal cord can cause pain. Nerve compression can also cause weakness and numbness in the upper arm and chest.
  • Shingles (herpes zoster infection of the nerves): Shingles is nerve irritation from the infection, which can cause chest pain days before any typical rash appears.
  • Esophageal spasm and reflux: The esophagus is the long muscular tube connecting the mouth to the stomach. Reflux, or regurgitation of stomach contents and acid into the esophagus can cause heartburn and chest pain. Spasm of the muscle of the esophagus can also cause chest pain which can be indistinguishable from chest pain caused by angina or a heart attack. The cause of esophageal muscle spasm is not known. Pain of esophageal spasm can respond to nitroglycerin in a similar manner as angina.
  • Gallbladder attack (gallstones): Gallstones can block the gallbladder or bile ducts and cause severe pain of the upper abdomen, back and chest. Gallbladder attacks can mimic the pain of angina and heart attack.
  • Anxiety and panic attacks: Anxiety, depression, and panic attacks are frequently associated with chest pain lasting from minutes to days. The pain can be sharp or dull. It is usually accompanied by shortness of breath, or the inability to take a deep breath. Emotional stress can aggravate chest pain, but the pain is generally not related to exertion, and is not relieved by nitroglycerin. These patients often breath too fast (hyperventilate), causing lightheadedness, numbness, and tingling in the lips and fingers. Coronary artery disease risk factors are typically absent in these patients. Since there is no test for panic attacks, patients with chest pain usually undergo tests to exclude coronary artery disease and other causes of chest pain.

Why is it important to establish the diagnosis of angina?

Angina is usually a warning sign of the presence of significant coronary artery disease. Patients with angina are at risk of developing a heart attack (myocardial infarction). A heart attack is the death of heart muscle precipitated by the complete blockage of a diseased coronary artery by a blood clot.

During angina, the lack of oxygen (ischemia) to the heart muscle is temporary and reversible. The lack of oxygen to the heart muscle resolves and the chest pain disappears when the patient rests. In contrast, the muscle damage in a heart attack is permanent. The dead muscle turns into scar tissue when healed. A scarred heart cannot pump blood as efficiently as a normal heart, and can lead to heart failure.

Up to 25% of patients with significant coronary artery disease have no symptoms at all, even though they clearly lack adequate blood and oxygen supply to the heart muscle. These patients have "silent" angina. They have the same risk of heart attack as those with symptoms of angina.

How is angina diagnosed?

The electrocardiogram (EKG) is a recording of the electrical activity of the heart muscle, and can detect heart muscle which is in need of oxygen. The EKG is useful in showing changes caused by inadequate oxygenation of the heart muscle or a heart attack.

Exercise stress test

In patients with a normal resting EKG, exercise treadmill or bicycle testing can be useful screening tools for coronary artery disease. During an exercise stress test (also referred to as stress test, exercise electrocardiogram, graded exercise treadmill test, or stress ECG), EKG recordings of the heart are performed continuously as the patient walks on a treadmill or pedals on a stationary bike at increasing levels of difficulty. The occurrence of chest pain during exercise can be correlated with changes on the EKG, which demonstrates the lack of oxygen to the heart muscle. When the patient rests, the angina and the changes on the EKG which indicate lack of oxygen to the heart can both disappear. The accuracy of exercise stress tests in the diagnosis of significant coronary artery disease is 60% to 70%. If the exercise stress test does not show signs of coronary artery disease, a nuclear agent (thallium) can be given intravenously during exercise stress test. The addition of thallium allows nuclear imaging of blood flow to different regions of the heart, using an external camera. A reduced blood flow in an area of the heart during exercise, with normal blood flow to the area at rest, signifies significant artery narrowing in that region of the heart.

Stress echocardiography

Stress echocardiography combines echocardiography (ultrasound imaging of the heart muscle) with exercise stress testing. Like the exercise thallium test, stress echocardiography is more accurate than an exercise stress test in detecting coronary artery disease. When a coronary artery is significantly narrowed, the heart muscle supplied by this artery does not contract as well as the rest of the heart muscle during exercise. Abnormalities in muscle contraction can be detected by echocardiography. Stress echocardiography and thallium stress tests are both about 80% to 85% accurate in detecting significant coronary artery disease.

When a patient cannot undergo exercise stress test because of neurological or orthopedic difficulties, medications can be injected intravenously to simulate the stress on the heart normally brought on by exercise. Heart imaging can be performed with a nuclear camera or echocardiography.

Cardiac catheterization

Cardiac catheterization with angiography (coronary arteriography) is a technique that allows x-ray pictures to be taken of the coronary arteries. It is the most accurate test to detect coronary artery narrowing. Small hollow plastic tubes (catheters) are advanced under x-ray guidance to the openings of the coronary arteries. Iodine contrast "dye" is injected into the arteries while an x-ray video is recorded. Coronary arteriography gives the doctor a picture of the location and severity of coronary artery disease. This information can be important in helping doctors select treatment options.

CT coronary angiogram

CT coronary angiography is procedure that uses an intravenous dye that contains iodine, and CT scanning to image the coronary arteries. While the use of catheters is not necessary (thus the term "noninvasive" test applies to this procedure), there are still some risks involved, including the following:

  • Patients allergic to iodine
  • Patients with abnormal kidney function
  • Radiation exposure which is similar to, if not greater than, that received with a conventional coronary angiogram.

Nonetheless, this is generally a very safe test for most people. It is a major tool in the diagnosis of coronary artery disease in patients:

  • at high risk for developing coronary disease (cigarette smokers, those with genetic risk, high cholesterol levels, hypertension, or diabetes),
  • who have unclear results with exercise stress tests or other testing, or
  • who have symptoms suspicious of coronary disease

What are the treatment options for angina patients?

Treatment options include:

Medications

Nitroglycerin

Resting, nitroglycerin tablets (placed under the tongue), and nitroglycerin sprays all relieve angina by reducing the heart muscle's demand for oxygen. Nitroglycerin also relieves spasm of the coronary arteries and can redistribute coronary artery blood flow to areas that need it most. Short-acting nitroglycerin can be repeated at five minute intervals. When 3 doses of nitroglycerin fail to relieve the angina, further medical attention is recommended. Short-acting nitroglycerin can also be used prior to exertion to prevent angina.

Longer-acting nitroglycerin preparations, such as Isordil tablets, Nitro-Dur transdermal systems (patch form), and Nitrol ointment are useful in preventing and reducing the frequency and intensity of episodes in patients with chronic angina. The use of nitroglycerin preparations may cause headaches and lightheadedness due to an excess lowering of blood pressure.

Beta Blockers

Beta blockers relieve angina by inhibiting the effect of adrenaline on the heart. Inhibiting adrenaline decreases the heart rate, lowers the blood pressure, and reduces the pumping force of the heart muscle, all of which reduce the heart muscle's demand for oxygen. Beta blockers include:

Side effects include:

Calcium Channel Blockers

Calcium channel blockers relieve angina by lowering blood pressure, and reducing the pumping force of the heart muscle, thereby reducing muscle oxygen demand. Calcium channel blockers also relieve coronary artery spasm. Calcium channel blockers include:

Side effects include:

  • swelling of the legs,
  • excess lowering of the heart rate and blood pressure, and
  • depressing heart muscle function.

Miscellaneous anti-anginal drugs

New drugs are being studied to treat angina. In 2006, the FDA approved ranolazine (Ranexa). Because of its side effects (potential to cause abnormal heart rhythm), ranolazine is indicated only after other conventional drug treatments are found to be ineffective.

Angioplasty and coronary artery bypass surgery

When patients continue to have angina despite maximally tolerated combinations of nitroglycerin medications, beta blockers and calcium channel blockers, cardiac catheterization with coronary arteriography is indicated. Depending on the location and severity of the disease in the coronary arteries, patients can be referred for balloon angioplasty (percutaneous transluminal coronary angioplasty or PTCA) or coronary artery bypass graft surgery (CABG) to increase coronary artery blood flow.

What's new in the evaluation of angina?

A newly developed computerized x-ray scan (ultrafast CT scan) is highly accurate in detecting small amounts of calcium in the plaque of coronary arteries. If an ultrafast CT scan shows no calcium in the arteries, atherosclerotic coronary artery disease is unlikely. Ultrafast CT scanning is useful in evaluating chest pain in younger patients (men under 40 and women under 50 years old). Since young people do not normally have significant coronary artery plaque, a negative ultrafast CT scan makes the diagnosis of coronary artery disease unlikely. However, finding calcium by this method is less meaningful in older patients who are likely to have mild plaquing simply from the aging process.

Even though an ultrafast CT scan is useful in detecting calcium in plaque, it cannot determine whether the calcium-laden plaque actually causes artery narrowing and reduces blood flow. For example, a patient with a densely calcified plaque causing minimal or no artery narrowing will have a strongly positive ultrafast CT scan but a normal exercise treadmill test. In most patients who are suspected of having angina due to coronary artery disease, an exercise treadmill study is usually the first step in determining whether any plaque is clinically significant. Newer very high speed CT scanners can actually detect true coronary artery plaques and lesions similar to coronary angiography.

Magnetic resonance imaging (MRI), using magnetism and radio waves, can be used to image (produce a likeness of) the blood vessels. Currently, the larger vessels, such as the carotid arteries in the neck, can be imaged using this technique. Future software and hardware improvements may allow screening of the heart's arteries with magnetic resonance testing.

What's new in the treatment of angina and heart attacks?

Coronary arteries can close after angioplasty, causing recurrent angina or even heart attacks. One way to decrease the risk of coronary artery closure is by deploying stents to keep the arteries open. Newer drug-coated stents are being improved to significantly reduce the rate of artery closure.

Angina At A Glance
  • Angina is one of many causes of chest pain.
  • Angina is chest pain that is a result of inadequate oxygen supply to the heart muscle.
  • Angina can be caused by coronary artery disease or spasm of the coronary arteries.
  • EKG, exercise stress test, stress echocardiography, stress thallium, and cardiac catheterization are important in the diagnosis of angina.
  • Treatment of angina includes rest, medications, angioplasty, and/or coronary artery bypass surgery.