Arrhythmias

What is an arrhythmia?

An arrhythmia (also referred to as dysrhythmia) is an abnormal rhythm of the heart, which can cause the heart to pump less effectively.

Arrhythmias can cause problems with contractions of the heart chambers by:

• Not allowing the ventricles (lower chambers) to fill with an adequate amount of blood because an abnormal electrical signal is causing the heart to pump too fast.

• Not allowing a sufficient amount of blood to be pumped out to the body because an abnormal electrical signal is causing the heart to pump too slowly or too irregularly.

In any of these situations, the body's vital organs may not receive enough blood.

What are the symptoms of arrhythmias?

The effects on the body are often the same, however, whether the heartbeat is too fast, too slow, or too irregular. Some symptoms of arrhythmias include, but are not limited to:

• Palpitations (a sensation of fluttering or irregularity of the heartbeat) 

• Weakness

• Fatigue

• Low blood pressure

• Dizziness

• Fainting

• Difficulty feeding (in babies)

The symptoms of arrhythmias may resemble other conditions. Consult your doctor for a diagnosis.

To better understand arrhythmias, is it helpful to understand the heart's electrical conduction system.

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The heart's electrical system

The heart is, in the simplest terms, a pump made up of muscle tissue. The heart's pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart.

How does the heart beat?

An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node), consisting of a small mass of specialized tissue located in the right atrium (right upper chamber) of the heart. The sinus node generates a regular electrical stimulus, which for adults, is usually 60 to 100 times per minute under normal conditions. This electrical stimulus travels down through the conduction pathways (similar to the way electricity flows through power lines from the power plant to your house) and causes the heart's lower chambers to contract and pump out blood. The right and left atria (the two upper chambers of the heart) are stimulated first and contract a short period of time before the right and left ventricles (the two lower chambers of the heart). 

The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node), where impulses are slowed down for a very short period, then allowed to continue down the conduction pathway via an electrical channel called the bundle of His into the ventricles. The bundle of His divides into right and left pathways to provide electrical stimulation to the right and left ventricles. Each contraction of the ventricles represents one heartbeat. 

Each day the heart beats about 100,000 times, on average. Any dysfunction in the heart's electrical conduction system can make the heartbeat too fast, too slow, or at an uneven rate, thus, causing an arrhythmia.

What is an electrocardiogram (ECG)?

The electrical activity of the heart is measured by an electrocardiogram (ECG or EKG). By placing electrodes at specific locations on the body (chest, arms, and legs), a graphic representation, or tracing, of the electrical activity can be obtained. Changes in an ECG from the normal tracing can indicate arrhythmias, as well as other heart-related conditions.

What does an ECG mean?

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Almost everyone knows what a basic ECG tracing looks like. But what does it mean?

• The first little upward notch of the ECG tracing is called the "P wave." The P wave indicates that the atria (the two upper chambers of the heart) are electrically stimulated to pump blood to the ventricles.

• The next short flat segment is called the "PR interval." The PR interval represents the delay in the conduction of the electrical signal from the atria to the ventricles.

• The next part of the tracing is a short downward section connected to a tall upward section. This part is called the "QRS complex." This part indicates that the ventricles (the two lower chambers of the heart) are electrically stimulated (undergo depolarization) to pump out blood to the body.

• The next short flat segment is called the "ST segment." The ST segment indicates that the ventricles are depolarized and that the electrical signal for ventricular contraction is completed.

• The next upward curve is called the "T wave." The T wave indicates the electrical recovery period of the ventricles (ventricular repolarization) in preparation for the next electrical depolarization and mechanical contraction.

When your doctor studies your ECG, he or she looks at the size and length of each part of the ECG. Variations in size and length of the different parts of the tracing may be significant. The tracing for each lead of a 12-lead ECG will look different, but will have the same basic components as described above. Each lead of the 12-lead is "looking" at a specific part of the heart, so variations in a lead may indicate a problem with the part of the heart associated with the lead.

What are the different types of arrhythmias?

An atrial arrhythmia is caused by abnormal function of the sinus node or the atrioventricular node, or by the development of another atrial pacemaker within the atrium that takes over the function of the sinus node.

A ventricular arrhythmia is caused by an abnormal electrical focus within the ventricles, resulting in abnormal conduction of electrical signals within the ventricles. The sinus node and atrioventricular node may function normally.

 Arrhythmias can also be classified as slow (bradyarrhythmia) or fast (tachyarrhythmia). "Brady-" means slow, while "tachy-" means fast.

Listed below are some of the more common arrhythmias:

The symptoms of various arrhythmias may resemble other medical conditions. Consult your doctor for a diagnosis.

How are arrhythmias diagnosed?

There are several different types of procedures that may be used to diagnose arrhythmias. Some of these procedures include the following:

• Electrocardiogram (ECG or EKG). An electrocardiogram is a measurement of the electrical activity of the heart. By placing electrodes at specific locations on the body (chest, arms, and legs), a graphic representation, or tracing, of the electrical activity can be obtained as the electrical activity is received and interpreted by an ECG machine. An ECG can indicate the presence of arrhythmias, damage to the heart caused by ischemia (lack of oxygen to the heart muscle) or myocardial infarction (MI, or heart attack), a problem with one or more of the heart valves, or other types of heart conditions.

There are several variations of the ECG test:

• Resting ECG. For this procedure, the clothing on the upper body is removed and small sticky patches called electrodes are attached to the chest, arms, and legs. These electrodes are connected to the ECG machine by wires. The ECG machine is then started and records the heart's electrical activity for a minute or so. The patient is lying down during this ECG.

• Exercise ECG, or stress test. The patient is attached to the ECG machine as described above. However, rather than lying down, the patient exercises by walking on a treadmill or pedaling a stationary bicycle while the ECG is recorded. This test is done to assess changes in the ECG during stress, such as exercise.

• Signal-averaged ECG. This procedure is done in the same manner as a resting ECG, except that the heart's electrical activity is recorded over a longer period of time, usually 15 to 20 minutes. Signal-averaged ECGs are done when arrhythmia is suspected but not seen on a resting ECG. The signal-averaged ECG has increased sensitivity to abnormal ventricular activity called "late potentials." Signal-averaged ECG is used in research and seldom used in clinical practice.

• Electrophysiologic studies (EPS). An invasive test in which a small, thin tube (catheter) is inserted in a large blood vessel in the leg or arm and advanced to the heart. This gives the doctor the capability of finding the site of the arrhythmia's origin within the heart tissue, thus determining how to best treat it. Another procedure called an esophageal electrophysiologic study may be ordered where a soft, thin flexible plastic tube is inserted in the nostril and placed in the esophagus (close to the atria) to provide a more precise ECG recording.

• Holter monitor. A continuous ECG recording done over a period of 24 or more hours. Electrodes are attached to the patient's chest and connected to a small portable ECG recorder by lead wires. The patient goes about his or her usual daily activities (except for activities such as taking a shower, swimming, or any activity causing an excessive amount of sweating that would cause the electrodes to become loose or fall off) during this procedure.
  Holter monitoring may be done when an arrhythmia is suspected but not seen on a resting ECG, since arrhythmias may be transient in nature and not seen during the shorter recording times of the resting ECG.

• Event monitor. This is similar to a Holter monitor, but the ECG is recorded only when the patient starts the recording when symptoms are felt. Event monitors are typically worn longer than Holter monitors. The monitor can be removed to allow for showering or bathing. 

• Mobile cardiac monitoring. This is similar to both a Holter and event monitor. The ECG is monitored constantly to allow for detection of arrhythmias, which are recorded and sent to your doctor regardless of whether symptoms are experienced. Recordings can also be initiated by the patient when symptoms are felt. These monitors can be worn up to 30 days. 

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How are arrhythmias treated?

Some arrhythmias may be present but cause few, if any, problems. In this case, the doctor may elect not to treat the arrhythmia. However, when the arrhythmia causes symptoms, there are several different options for treatment. The doctor will choose an arrhythmia treatment based on the type of arrhythmia, the severity of symptoms being experienced, and the presence of other conditions (diabetes, kidney failure, heart failure, etc.) which can affect the course of the treatment.

Some treatments for arrhythmias include:

• Lifestyle modification. Factors, such as stress, caffeine, or alcohol, can cause arrhythmias. The doctor may order the elimination of caffeine, alcohol, or any other substances believed to be causing the problem. If stress is suspected as a cause, the doctor may recommend stress-reduction measures, such as meditation, stress-management classes, an exercise program, or psychotherapy.

• Medication. There are various types of medications that may be used to treat arrhythmias. If the doctor chooses to use medication, the decision of which medication to use will be determined by the type of arrhythmia, other conditions which may be present, and other medications already being taken by the patient.

• Cardioversion. In this procedure, an electrical shock is delivered to the heart through the chest to stop certain very fast arrhythmias such as atrial fibrillation, supraventricular tachycardia, or atrial flutter. The patient is connected to an ECG monitor which is also connected to the defibrillator. The electrical shock is delivered at a precise point during the ECG cycle to convert the rhythm to a normal one.

• Ablation. This is an invasive procedure done in the electrophysiology laboratory, which means that a catheter (a very thin, flexible hollow tube) is inserted into the heart through a vessel in the groin or arm. The procedure is done in a manner similar to the electrophysiology studies (EPS) described above. Once the site of the arrhythmia has been determined by EPS, the catheter is moved to the site. By use of a technique, such as radiofrequency ablation (very high frequency radio waves are applied to the site, heating the tissue until the site is destroyed) or cryoablation (an ultra-cold substance is applied to the site, freezing the tissue and destroying the site), the site of the arrhythmia may be destroyed.

• Pacemaker. A permanent pacemaker is a small device that is implanted under the skin (most often in the shoulder area just under the collar bone), and sends electrical signals to start or regulate a slow heart beat. A permanent pacemaker may be used to make the heart beat if the heart's natural pacemaker (the SA node) is not functioning properly and has developed an abnormal heart rate or rhythm or if the electrical pathways are blocked. Pacemakers are typically used for slow arrhythmias such as sinus bradycardia, sick sinus syndrome, or heart block.

• Implantable cardioverter defibrillator. An implantable cardioverter defibrillator (ICD) is a small device, similar to a pacemaker, that is implanted under the skin, often in the shoulder area just under the collarbone. An ICD senses the rate of the heartbeat. When the heart rate exceeds a rate programmed into the device, it delivers a small, electrical shock to the heart in order to shock the heart back to a slower more normal heart rhythm. Newer ICDs are combined with a pacemaker to deliver an electrical signal to regulate a heart rate that is too slow. ICDs are used for life-threatening fast arrhythmias such as ventricular tachycardia or ventricular fibrillation.

• Surgery. Surgical treatment for arrhythmias is usually done only when all other appropriate options have failed. Surgical ablation is a major surgical procedure requiring general anesthesia. The chest is opened, exposing the heart. The site of the arrhythmia is located, the tissue is destroyed or removed in order to eliminate the source of the arrhythmia.

Last Modified Date: 2012-02-28T00:00:00-07:00
Created Date: 2007-03-30T00:00:00-06:00
Published Date: 2012-03-07T06:11:00.28-07:00
Copyright Date: 2012
Copyright Statement: © 2000-2012 Krames StayWell, 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Congenital Heart Defects

What is a congenital heart defect?

When the heart or blood vessels near the heart do not develop normally before birth, a condition called congenital heart defect occurs (congenital means "inborn" or "existing at birth").

Congenital heart defects occur in about eight of every 1,000 infants. More than 1,000,000 adults in the U.S. have congenital heart disease. Many young people with congenital heart defects are living into adulthood now.

In most cases, the cause is unknown. Sometimes a viral infection or hereditary causes the condition. Some congenital heart defects are the result of too much alcohol or drug use during pregnancy.

Most heart defects either cause an abnormal blood flow through the heart, or obstruct blood flow in the heart or vessels (obstructions are called stenoses and can occur in heart valves, arteries, or veins).

Rarely, defects include those in which:

• The right or left side of the heart is incompletely formed and is called hypoplastic heart.

• Only one ventricle is present.

• Both the pulmonary artery and aorta arise from the same ventricle.

• The pulmonary artery and aorta arise from the "wrong" ventricles. 

Types of congenital heart defects

There are many disorders of the heart that require clinical care by a doctor or other health care professional. Listed below are some of the conditions, for which we have provided a brief overview.

Obstructive defects:

• Aortic stenosis (AS). In this condition, the aortic valve between the left ventricle and the aorta did not form properly and is narrowed, making it difficult for the heart to pump blood to the body. A normal valve has three leaflets or cusps, but a stenotic valve may have only one cusp (unicuspid) or two cusps (bicuspid).
  
  In some children, chest pain, unusual tiring, dizziness or fainting may occur. Otherwise, most children with aortic stenosis have no symptoms. But, even mild stenosis may worsen over time, and surgery may be needed to correct the blockage or the valve may need to be replaced with an artificial one.

• Pulmonary stenosis (PS). The pulmonary, or pulmonic, valve, located between the right ventricle and the pulmonary artery, opens to allow blood to flow from the right ventricle to the lungs. When a defective pulmonary valve does not open properly, it causes the heart to pump harder than normal to overcome the obstruction. Usually, the obstruction can be corrected by balloon valvuloplasty, although in some patients, open heart surgery may be needed.

• Bicuspid aortic valve. In this condition, an infant is born with a bicuspid valve which has only two flaps. (A normal aortic valve has three flaps that open and close). If the valve becomes narrowed, it is more difficult for the blood to flow through, and often the blood leaks backward. Symptoms usually do not develop during childhood, but are often detected during the adult years.

• Subaortic stenosis. This condition refers to a narrowing of the left ventricle just below the aortic valve. Normally, blood passes through it to go into the aorta. However, subaortic stenosis limits the blood flow out of the left ventricle, often resulting in an increased workload for the left ventricle. Subaortic stenosis may be congenital or caused by a form of cardiomyopathy.

• Coarctation of the aorta (coarct). In this condition, the aorta is narrowed or constricted, obstructing blood flow to the lower part of the body and increasing blood pressure above the constriction. Usually there are no symptoms at birth, but they can develop as early as the first week after birth. If severe symptoms of high blood pressure and congestive heart failure develop, surgery may be considered.

Septal defects

Some congenital heart defects allow blood to flow between the right and left chambers of the heart because an infant is born with an opening in the septal wall that separates the right and left sides of the heart.

• Atrial septal defect (ASD). In this condition, there is an abnormal opening between the two upper chambers of the heart--the right and left atria--causing an abnormal blood flow through the heart. Children with ASD have few symptoms. Closing the atrial defect by open heart surgery in childhood can often prevent serious problems later in life.

• Ebstein's anomaly. In this defect, there is a downward displacement of the tricuspid valve (located between the upper and lower chambers on the right side of the heart) into the right bottom chamber of the heart (or right ventricle). It is usually associated with an atrial septal defect.

• Ventricular septal defect (VSD). In this condition, a hole occurs between the two lower chambers of the heart. Because of this hole, blood from the left ventricle flows back into the right ventricle, due to higher pressure in the left ventricle. This causes an extra volume of blood to be pumped into the lungs by the right ventricle, which can create congestion in the lungs.

Cyanotic defects

Cyanotic defects are defects in which blood pumped to the body contains less-than-normal amounts of oxygen, resulting in a condition called cyanosis. It causes a blue discoloration of the skin. Infants with cyanosis are often called "blue babies."

• Tetralogy of Fallot. This condition is characterized by four defects, including the following:

  • An abnormal opening, or ventricular septal defect, that allows blood to pass from the right ventricle to the left ventricle without going through the lungs

  • A narrowing (stenosis) at or just beneath the pulmonary valve that partially blocks the flow of blood from the right side of the heart to the lungs

  • The right ventricle is more muscular than normal

  • The aorta lies directly over the ventricular septal defect

  
  Tetralogy of Fallot is the most common defect causing cyanosis in persons beyond 2 years of age. Most children with tetralogy of Fallot have open-heart surgery before school age to close the ventricular septal defect and remove the obstructing muscle. Lifelong medical follow-up is needed.

• Tricuspid atresia. In this condition, there is no tricuspid valve, therefore, no blood flows from the right atrium to the right ventricle. Tricuspid atresia defect is characterized by the following:

  • A small right ventricle

  • A large left ventricle

  • Diminished pulmonary circulation

  • Cyanosis

  
  A surgical shunting procedure is often necessary to increase the blood flow to the lungs.

• Transposition of the great arteries. In this embryologic defect, the positions of the pulmonary artery and the aorta are reversed, thus:

  • The aorta originates from the right ventricle, so most of the blood returning to the heart from the body is pumped back out without first going to the lungs.

  • The pulmonary artery originates from the left ventricle, so that most of the blood returning from the lungs goes back to the lungs again.

  
  Immediate medical intervention is necessary to correct this condition.

Other defects:

• Hypoplastic left heart syndrome (HLHS). In this condition, the left side of the heart is underdeveloped, including the aorta, aortic valve, left ventricle, and mitral valve. Blood reaches the aorta through a patent ductus arteriosus, and if this ductus closes, as is normal, the baby will die. The baby often seems normal at birth, but the condition will become noticeable within a few days of birth, as the ductus closes. Babies with this syndrome become ashen (gray), have diminished or absent pulses in the legs, have difficulty breathing, and are unable to feed. Treatment may include complex surgery or a heart transplant.

• Patent ductus arteriosus (PDA). This defect, which normally occurs during the fetal life, short circuits the normal pulmonary vascular system and allows blood to mix between the pulmonary artery and the aorta. Prior to birth, there is an open passageway between the two blood vessels, which closes soon after birth. When it does not close, some blood returns to the lungs. Patent ductus arteriosus is often seen in premature infants.

Who treats congenital heart defects?

Babies with congenital heart problems are followed by specialists called pediatric cardiologists. These physicians diagnose heart defects and help manage the health of children before and after surgical repair of the heart problem. Specialists who correct heart problems in the operating room are known as pediatric cardiovascular or cardiothoracic surgeons.

A new subspecialty within cardiology is emerging as the number of adults with congenital heart disease (CHD) is now greater than the number of babies born with CHD, as a result of the advances in diagnostic procedures and treatment interventions that have been made since 1945.

In order to achieve and maintain the highest possible level of wellness, it is imperative that those individuals born with CHD who have reached adulthood transition to the appropriate type of cardiac care. The type of care required is based on the type of CHD a person has. Those persons with simple CHD can generally be cared for by a community adult cardiologist. Those with more complex types of CHD will need to be cared for at a center that specializes in adult CHD.

For adults with CHD, guidance is necessary for planning key life issues such as college, career, employment, insurance, activity, lifestyle, inheritance, family planning, pregnancy, chronic care, disability, and end of life. Knowledge about specific congenital heart conditions and expectations for long-term outcomes and potential complications, and risks must be reviewed as part of the successful transition from pediatric care to adult care. Parents should help pass on the responsibility for this knowledge and accountability for ongoing care to their young adult children to help ensure the transition to adult specialty care and optimize the health status of the young adult with CHD.

Last Modified Date: 2012-02-07T00:00:00-07:00
Created Date: 2007-03-30T00:00:00-06:00
Published Date: 2012-03-09T19:43:12.81-07:00
Copyright Date: 2012
Copyright Statement: © 2000-2012 Krames StayWell, 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Heart Failure

What is heart failure?

Heart failure, also called congestive heart failure, is a condition in which the heart cannot pump enough oxygenated blood to meet the needs of the body's other organs. The heart keeps pumping, but not as efficiently as a healthy heart. Usually, the heart's diminished capacity to pump reflects a progressive, underlying condition. Nearly 5 million Americans are living with heart failure, and 400,000 to 700,000 new cases are diagnosed each year.

What causes heart failure?

Heart failure may result from any or all of the following:

• Heart valve disease caused by past rheumatic fever or other infections

• High blood pressure (hypertension)

• Active infections of the heart valves and/or heart muscle (for example, endocarditis or myocarditis)

• Previous heart attack(s) (myocardial infarction). Scar tissue from prior damage may interfere with the heart muscle's ability to pump normally.

• Coronary artery disease. Narrowing of the arteries that supply blood to the heart muscle.

• Cardiomyopathy or another primary disease of the heart muscle

• Congenital heart disease or defects (present at birth)

• Cardiac arrhythmias (irregular heartbeats)

• Chronic lung disease and pulmonary embolism

• Certain medications

• Excessive sodium intake

• Anemia and excessive blood loss

• Complications of diabetes

How does heart failure affect the body?

Heart failure interferes with the kidney's normal function of eliminating excess sodium and waste products from the body. In congestive heart failure, the body retains more fluid, resulting in swelling of the ankles and legs. Fluid also collects in the lungs, which can cause profound shortness of breath.

What are the symptoms of heart failure?

The following are the most common symptoms of heart failure. However, each individual may experience symptoms differently. Symptoms may include:

• Shortness of breath during rest, exercise, or while lying flat

• Weight gain

• Visible swelling of the legs and ankles (due to a buildup of fluid), and, occasionally, swelling of the abdomen

• Fatigue and weakness

• Loss of appetite, nausea, and abdominal pain

• Persistent cough that can cause blood-tinged sputum

The severity of the condition and symptoms depends on how much of the heart's pumping capacity has been compromised.

The symptoms of heart failure may resemble other conditions or medical problems. Always consult your health care provider for a diagnosis.

How is heart failure diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for heart failure may include any, or a combination of, the following:

• Chest X-ray. A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

• Echocardiogram (also called echo). A noninvasive test that uses sound waves to evaluate the motion of the heart's chambers and valves. The echo sound waves create an image on the monitor as an ultrasound transducer is passed over the heart.

• Electrocardiogram (ECG or EKG). A test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and can sometimes detect heart muscle damage.

• BNP testing. B-type natriuretic peptide (BNP) is a hormone released from the ventricles in response to increased wall tension (stress) that occurs with heart failure. BNP levels rise as wall stress increases. BNP levels are useful in the rapid evaluation of heart failure. In general, the higher the BNP levels, the worse the heart failure.

Treatment for heart failure

Specific treatment for heart failure will be determined by your health care provider based on:

• Your age, overall health, and medical history

• Extent of the disease

• Your tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

The cause of the heart failure will dictate the treatment protocol established. If the heart failure is caused by a valve disorder, then surgery may be performed. If the heart failure is caused by a disease, such as anemia, then the underlying disease will be treated. Although there is no cure for heart failure due to damaged heart muscle, many forms of treatment have been used to treat symptoms very effectively.

The goal of treatment is to improve a person's quality of life by making the appropriate lifestyle changes and implementing drug therapy.

Treatment of heart failure may include:

• Controlling risk factors:

  • Losing weight (if overweight)

  • Restricting salt and fat from the diet

  • Stop smoking

  • Abstaining from alcohol

  • Proper rest

  • Controlling blood sugar if diabetic

  • Controlling blood pressure

  • Limiting fluids

• Medication, such as:

  • Angiotensin converting enzyme (ACE) inhibitors. This medication decreases the pressure inside the blood vessels and reduces the resistance against which the heart pumps.

  • Angiotensin receptor blockers (ARB). This is alternative medication for reducing workload on the heart if ACE inhibitors are not tolerated.

  • Diuretics. These reduce the amount of fluid in the body.

  • Vasodilators. These dilate the blood vessels and reduce workload on the heart.

  • Digitalis. This medication helps the heart beat stronger with a more regular rhythm. 

  • Inotropes. These increase the pumping action of the heart muscle.

  • Antiarrhythmia medications. These help maintain normal heart rhythm and help prevent sudden cardiac death.

  • Beta-blockers. These reduce the heart's tendency to beat faster and reduce workload by blocking specific receptors on heart cells.

  • Aldosterone blockers. Medication that blocks the effects of the hormone aldosterone which causes sodium and water retention.

• Biventricular pacing/cardiac resynchronization therapy. A new type of pacemaker that paces both pumping chambers of the heart simultaneously to coordinate contractions and to improve the heart's function. Some heart failure patients are candidates for this therapy.

• Implantable cardioverter defibrillator. A device similar to a pacemaker that senses when the heart is beating too fast and delivers an electrical shock to convert the fast rhythm to a normal rhythm.

• Heart transplantation

• Ventricular assist devices (VADs)

Ventricular assist devices (VADs)

A ventricular assist device (VAD) is a mechanical device that is used to take over the pumping function for one or both of the heart's ventricles, or pumping chambers. A VAD may be necessary when heart failure progresses to the point that medications and other treatments are no longer effective.

For persons with severe or end-stage heart failure, ventricular assist devices (VADs) may be required to support the heart in order to ensure an adequate cardiac output (amount of blood pumped out by the heart per minute) to meet the body's needs.

Heart transplantation is an option for some patients with severe heart failure (HF), but during this late stage of HF, over 50 percent of persons on a waiting list for heart transplantation will die before receiving a donor heart. Organ donors are in short supply and do not meet the demand for patients waiting for heart transplant. The wait time for heart transplantation varies from days to months.

Long wait times and decreased availability of donors has led doctors and researchers to seek other methods to support the failing heart. Patients may die waiting for a transplant or other important organs such as the liver and kidney may become permanently damaged before a donor heart is available. VADs have shown great promise in maintaining adequate blood circulation in cases of severe HF.

VADs may be used in the following situations:

• Bridge to transplant. The implantation of a VAD to support the patient with end-stage HF who is waiting for heart transplantation.

• Bridge to recovery. The implantation of a VAD to support the patient with potentially reversible HF. Once the heart has recovered sufficiently, the VAD may be removed.

• Destination therapy. The implantation of a VAD to support the patient with end-stage HF who is not a candidate for heart transplantation. A portable VAD may be used in this situation so that the patient may be discharged from the hospital and return home.

The two basic types of VADs are left ventricular assist (LVAD), which is the most common, or the right ventricular assist (RVAD). If both are used at the same time it is called biventricular assist (BIVAD). However a BIVAD is not a separate type of VAD. 

VADs are most commonly implanted during a process similar to other types of open heart surgery.

All types of VADs have similar complications postoperatively and during prolonged therapy:

• Infection. Infection is a serious complication that occurs frequently. Patients in general are vulnerable to postoperative infections such as intravenous (IV) line infections, pneumonia, and urinary tact infections. The patient receiving a VAD is at even greater risk due in part to the patient's weakened state. VAD-related infections may occur at the skin where the device is inserted into the body, in the heart (endocarditis), or in the blood stream (sepsis).

  To minimize the risk of infections, all cannula (tubing) exit sites must be dressed daily using sterile technique, the exit cannulas must be secured to prevent tension and pulling on the skin, and the skin around all exit sites must be completely healed before extensive activity is allowed.

• Bleeding. Bleeding is common in the immediate postoperative period due to cardiopulmonary (heart-lung) bypass time, anticoagulation (prevention of blood clotting with medication), and long surgical procedures. Additionally, liver dysfunction (which may be present preoperatively) and previous heart surgeries increase the patient's risk for bleeding. Blood transfusions may be required for major bleeding, but are avoided if possible.

• Right ventricular failure. Right ventricular failure is a concern in patients who have high pressures in the lung circulation before implantation of a VAD. Medications can help support the right ventricle during the initial period of recovery until the device begins to improve the overall cardiac output.

• Thromboembolism (blood clot). Thromboembolism (blood clot) may cause strokes. All VADs increase the risk of clot formation because blood comes in contact with the surfaces of the mechanical pump and cannulas. Almost all VADs require some form of anticlotting medicines to reduce the risk of stroke. These medications may put the patient at greater risk for bleeding, however, and should be closely monitored.

Last Modified Date: 2012-02-06T00:00:00-07:00
Created Date: 2007-03-30T00:00:00-06:00
Published Date: 2012-02-06T08:30:22.553-07:00
Copyright Date: 2012
Copyright Statement: © 2000-2012 Krames StayWell, 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Pericarditis

What is pericarditis?

Pericarditis is inflammation of the pericardium, the thin sac (membrane) that surrounds the heart. There is a small amount of fluid between the inner and outer layers of the pericardium. Often, when the pericardium becomes inflamed, the amount of fluid between its two layers increases, causing a pericardial effusion. If the amount of fluid increases quickly, the effusion caused can impair the ability of the heart to function properly. A complication of pericarditis, which is a  serious condition, is called cardiac tamponade.

What are the symptoms of pericarditis?

The following are the most common indicators of pericarditis. However, individuals may experience symptoms differently. Symptoms may include:

• Chest pain that:

  • Can especially be felt behind the breastbone, sometimes felt beneath the clavicle (collarbone), neck, and left shoulder.

  • Is a sharp, piercing pain over the center or left side of the chest that increases if the person takes a deep breath and usually decreases if the person sits up or leans forward.

• Fever

• Pain when swallowing

• Arrhythmias (irregular heart beats)

The symptoms of pericarditis may resemble other conditions or medical problems. Consult your health care provider for a diagnosis.

What causes pericarditis?

Usually, the cause of pericarditis is unknown, but may include any or all of the following:

• Heart attack

• Infection (viral, bacterial, fungal, parasitic)

• Chest trauma or injury

• Cancer, tuberculosis, or kidney failure  

• Autoimmune disorders (i.e., systemic lupus erythematosus, rheumatoid arthritis, scleroderma)

• Medical therapies (certain medications, radiation therapy) 

• Heart surgery

Treatment for pericarditis

Specific treatment will be determined by your health care provider based on:

• Your age, overall health, and medical history

• Extent of the disease

• Cause of the disease

• Your tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

The goal of treatment for pericarditis is to determine and eliminate the cause of the disease. Treatment may include:

• Medication (i.e., analgesics, anti-inflammatory drugs, or antibiotics)

• Aspiration or removal of excess fluid

• Surgery

Pericarditis may last from two to six weeks, and there may be a recurrence of the disorder.

Last Modified Date: 2011-12-19T00:00:00-07:00
Created Date: 2007-03-30T00:00:00-06:00
Published Date: 2011-12-19T10:31:47.1-07:00
Copyright Date: 2012
Copyright Statement: © 2000-2012 Krames StayWell, 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.