HEART & BLOOD Cardiovascular System • Aortic aneurysm • High blood pressure (hypertension) • High blood cholesterol • Thrombophlebitis • Rheumatic fever • Varicose veins • Heart arrhythmias • Atrial fibrillation • Endocarditis • Aortic valve stenosis • Aortic valve regurgitation • Mitral valve stenosis • Mitral valve regurgitation • Pulmonary hypertension • Raynaud's disease • Long QT syndrome • Mitral valve prolapse • Pericarditis • Cardiomyopathy • Myocarditis • Arteriosclerosis / Atherosclerosis • Peripheral arterial disease (PAD) • Low blood pressure (hypotension) • Aortic dissection • Lymphedema • Pulmonary valve stenosis • Ventricular septal defect (VSD) • Tetralogy of Fallot • Coarctation of the aorta • Atrial septal defect (ASD) • Patent ductus arteriosus (PDA) • Left ventricular hypertrophy • Bundle branch block • Heart murmurs • Patent foramen ovale • Transposition of the great arteries • Hypoplastic left heart syndrome • Sudden cardiac arrest • Prehypertension • Tricuspid atresia • Ebstein's anomaly • Buerger's disease

Note: All links within content go to MayoClinic.com

A normal heartbeat makes two sounds like "lub-DUB," which are the sounds of your heart valves closing. Heart murmurs are abnormal sounds during your heartbeat — such as whooshing or swishing — made by turbulent blood in or near your heart.

Heart murmurs can be present at birth (congenital) or develop later in life. A heart murmur isn't a disease — but murmurs may indicate an underlying heart problem.

Most heart murmurs are harmless and don't need treatment. Doctors call these functional or "innocent" murmurs. A person with an innocent murmur has a normal heart. This type of heart murmur is common in newborns and children. More than half of all children have heart murmurs at some time, and most of those murmurs are innocent.

An abnormal heart murmur is more serious. In children, abnormal murmurs are usually the result of congenital heart disease. In adults, abnormal murmurs are most often due to acquired heart valve problems.

A doctor can evaluate heart sounds by listening to your heart with a stethoscope — and sometimes will have you undergo other tests to help determine the cause. Treatment, if needed, is directed at the underlying cause of your heart murmurs.

If you have an innocent heart murmur, you likely won't experience any signs or symptoms.

Frequently an abnormal heart murmur also has no associated symptoms. When the following signs or symptoms are present, they may indicate a heart problem:

• Skin that appears blue, especially on your fingertips and lips
• Swelling
• Shortness of breath
• Enlarged liver
• Enlarged neck veins
• Poor appetite and failure to grow normally (in infants)
• Weight gain (in adults and children)
• Heavy sweating with minimal or no exertion
• Chest pain
• Dizziness
• Fainting

The potential causes of heart murmurs are many.

Innocent heart murmurs
An innocent murmur can occur when blood flows more rapidly through the heart — such as during physical activity or exercise.

Conditions that also may cause blood to flow more rapidly through your heart, resulting in an innocent murmur, are:

• Pregnancy
• Fever
• Anemia, in which there aren't enough healthy red blood cells to carry adequate oxygen to your body tissues
• Hyperthyroidism, an excessive amount of thyroid hormone in your body
• Physical exertion

Changes to the heart due to aging or heart surgery also may cause an innocent heart murmur. Over time, innocent heart murmurs may disappear.

Abnormal heart murmurs
Although most murmurs aren't serious, some may result from a heart problem. The most common cause of abnormal murmurs in children is congenital heart disease — when babies are born with structural defects in the heart. Common congenital defects that cause murmurs include:

• Holes in the heart. More than half of abnormal murmurs in children are the result of holes in the walls between heart chambers or abnormal passageways between major blood vessels leaving the heart.
• Valve abnormalities. Examples include narrow valves that don't allow enough blood through them or those that don't close properly and leak.

Other causes of abnormal murmurs include infections and conditions that damage the structures of the heart. For example:

• Rheumatic fever. Rheumatic fever is a serious inflammatory condition that can occur when you don't receive prompt or complete treatment for a strep throat infection. In many cases, rheumatic fever may permanently affect the heart valves and interfere with normal blood flow through your heart. Prompt and proper treatment of strep throat with antibiotics can prevent strep throat from progressing to rheumatic fever.
• Endocarditis. This is an infection and inflammation of the inner lining of your heart and valves. Endocarditis typically occurs when bacteria or other germs from another part of your body, such as your mouth, spread through your bloodstream and lodge in your heart. Left untreated, endocarditis can damage or destroy your heart valves. This condition usually occurs in people who already have heart abnormalities.
• Valve calcification. This hardening or thickening of valves can occur as you age. These valves may not work as well as they once did, resulting in murmurs.

Doctors hear heart murmurs when using a stethoscope, a device that allows them to hear your heart and blood flow, during medical examinations.

To determine whether the murmur is innocent or abnormal, your doctor assesses:

• How loud is it? This is rated on a scale from 1 to 6, with 6 being the loudest.
• Where in your heart is it? And can it be heard in your neck or back?
• What pitch is it? Is it high-, medium- or low-pitched?
• What affects the sound? If you change your body position or exercise, does it affect the sound?
• When does it occur, and for how long? Systolic murmurs occur when your heart is squeezing blood out. Diastolic murmurs are heard when your heart is filling with blood. Continuous murmurs occur during the entire heartbeat. Both diastolic and continuous murmurs often indicate a heart defect or disease that needs more evaluation.

Your doctor will also look for other signs and symptoms of heart problems and ask about your medical history and whether other family members have had heart murmurs or other heart conditions.

Additional tests
If your doctor suspects the murmur is abnormal, he or she may do additional tests including:

• Chest X-ray. An image is created by directing X-rays at your chest and positioning a large piece of photographic film or a digital recording plate against your back. The X-ray machine produces a tiny burst of radiation that passes through your body and produces an image on the film or digital plate. A chest X-ray shows a picture of your heart, lungs and blood vessels. It can reveal if your heart is enlarged.
• Electrocardiogram (ECG). Each beat of your heart is triggered by an electrical impulse from special cells in the right upper chamber of your heart. The electrical impulse travels to other parts of your heart and causes your heart to squeeze. An ECG records these electrical signals and can help your doctor detect irregularities in your heart's rhythm and structure.

• Echocardiogram. This exam shows detailed images of your heart's structure and function. Ultrasound waves are transmitted, and their echoes are recorded with a device called a transducer held outside your body. A computer uses the information from the transducer to create moving images on a video monitor. This test identifies abnormal heart valves, such as those that are calcified or leaking, and can also detect most congenital heart defects.

  In some cases you may need a transesophageal ultrasound. During this exam, you swallow a flexible tube containing a small transducer, about the size of your index finger. Since the esophagus passes close to your heart, the transesophageal transducer can often produce better images than do sound waves transmitted through your chest.

• Cardiac catheterization. In this test, a short tube called a sheath is inserted into a vein or artery at the top of your leg (groin) or into your arm. A hollow, flexible and longer tube (guide catheter) is then inserted into the sheath. Aided by X-ray images on a monitor, your doctor threads the guide catheter through that artery until it reaches your heart. The pressures in your heart chambers can be measured, and dye can be injected. The dye can be seen on an X-ray, which helps your doctor see the blood flow through your heart, blood vessels and valves to check for abnormalities.

An innocent heart murmur generally doesn't require treatment because the heart is normal. If innocent murmurs are the result of a condition such as fever or hyperthyroidism, the murmurs will go away once that condition is treated.

If you have abnormal heart murmurs, treatment is often not necessary initially. Your doctor may want to monitor the condition over time. If treatment is necessary, it depends on what heart problem is causing your murmurs and may include medications or surgery.

Medications
The medication your doctor prescribes depends on the specific heart problem you have. Some medications your doctor might give you:

• Help your heart squeeze harder
• Prevent blood clots that block your blood vessels
• Remove excess fluid from your body
• Lower your blood pressure

Surgery
Surgical options also depend on your specific heart problem but may include:

• Patching a hole in your heart
• Fixing a valve
• Rebuilding a blood vessel
• Widening a blood vessel that's too narrow

In addition, if you have heart murmurs, you may need to be careful of infections that could travel to your heart. To avoid this, your doctor may prescribe antibiotics before you go to the dentist or have surgery — circumstances that can increase the chances of your getting an infection.