Heart Murmurs: some are innocent and some ain’t

Almost everyday, an individual goes to a doctor and finds out that he has a murmur. And he panics- in most cases the anxiety is unnecessary. In all individuals, the heart does make some noises. These noises come from the closing of the heart valves. Besides the heart sounds from the valves, there may also be other sounds heard which may frequently resemble a whisper. These whisper like sounds are known as murmurs. These murmurs are usually due to turbulence of the blood in the heart. Occasionally these audible murmurs may be entirely normal or may indicate something bad with the heart. Heart murmurs may be present soon after birth or may be heard later on in life. A heart murmur does not always indicate disease but sometimes may be indicative of an underlying heart problem. The sound of the murmur may be soft or loud. In children the most common causes of a heart murmur is a congenital heart defect. In adults, the most common cause of the heart murmur may be from a leaky valve or as a result of a complication of a heart attack. The sound of the murmurs may range from a harsh machinery type to a swishing sound. Some murmurs are loud, but most are soft and can only be heard with a stethoscope. Some heart murmurs are innocent (harmless). However, sometimes they are a sign of heart problems, especially if other symptoms of a heart problem are present. The majority of heart murmurs are innocent and not associated with any heart problems. These innocent or harmless murmurs are common in children. Infact 50% or more of these childhood murmurs are innocent. Any murmur which is heard after the age of 35 must be investigated.

In most cases the murmur is caused by turbulent flow across either the heart valves or some other structure. All murmurs are graded, the softer the murmur the less the grade. Murmurs are graded form 1-6 and this is a subjective evaluation. Any murmur which is graded more than 3 is considered bad. It indicates that there may be a problem with the heart. Murmurs are also described by their character such as soft, harsh, musical or vibratory. The average physician would be clueless in characterizing murmurs and the descriptions are only for academic purposes. Many functional or innocent murmurs have a musical or vibratory quality but this is neither diagnostic nor important. The location of the highest intensity of a murmur is also important. Different disorders of the heart may produce murmurs at different sites on the chest.

Innocent murmurs are heard when the blood moves noisily through a normal heart. Frequently the murmur occurs when: • there is a faster movement of blood through the heart chambers or the blood vessels • There is an increased amount of blood flowing through the heart chambers. Conditions that may cause blood to flow more rapidly through your heart, resulting in an innocent murmur are: • Pregnancy • Fever • Low red blood cell count (Anemia) • Excess thyroid hormone (hyperthyroidism) • Exercise • After bypass surgery A number of children will have a murmur at some point in their lives. The murmur may be heard when the child has a physical examination soon after starting school. Some murmurs may be heard soon after birth. Harmless murmurs are very common in healthy children. In the majority of cases, work up reveals that the child has no heart problems. Most such murmurs disappear as the child grows up.

When murmurs are heard in any individual with symptoms, it is indicative of a heart problem. The louder the murmur, the more serious the defect. Amy adult who has a murmur after the age of 35 should be worked up to ensure that there is no heart problem. In adults, the most common cause of abnormal heart murmurs are: • residual heart defects from birth • complications of a heart attack • infection of the heart • rheumatic fever • leaky valves • calcified valves In children, the most common cause of abnormal heart murmurs are: • congenital heart defects • leaky valves • structural heart defects • holes in the heart

Those individuals with an innocent murmur may have no symptoms. Infact the majority may not even know if they have a murmur. However, in those individuals who have a murmur with a heart defect, the symptoms may include: • bluish skin, which is prominent on the fingertips and lips • Swelling of legs • Shortness of breath • Faster heart rate • Large liver • Prominent veins in the neck area • Poor appetite • Failure to thrive • Chest pain • Shortness of breath • Dizziness or fainting spells • Sweating with minimal exertion • Constant fatigue

The murmurs are first always heard by a doctor with a stethoscope. Depending on the presence of other symptoms or signs, the physicians may order other investigations. The urgency of the tests is dependent on how one is feeling. In all individuals who have no symptoms, the tests can be done anytime. In those individuals who have symptoms, the tests should be done on an urgent basis. All individuals with murmurs are usually referred to physicians who specialize in evaluating and treating heart disorders After a comprehensive physical exam, the physician may order: Chest X-ray: The chest x ray may reveal if there is anything wrong with your heart, lungs or blood vessels. However, it is a very insensitive test to determine the cause of the murmur. ECG: Whenever a murmur is heard, electrical activity of the heart can be assessed by obtaining an ECG. This will reveal the rate, rhythm and regularity of your heart beat. Echocardiogram: This is basically an ultrasound of the heart. It is excellent for imaging the heart and can reveal the actual structures of the heart. Echo can be performed through the chest or by placing a probe in the swallowing tube (esophagus). In the majority of cases, the echo will identify the cause of the murmur. The cause of the majority of murmurs can be identified by an echocardiogram. Cardiac catheterization: Sometimes Echo may not be diagnostic and a procedure called cardiac angiography is required. This procedure requires the use of a dye and x rays. A small plastic tube is inserted from the groin blood vessel all the way to the heart and x rays are obtained of the heart. This test can reveal more details of the heart. It can reveal the presence of any heart defects and sampling of blood from the heart can also be done.

Innocent murmurs of the heart do not require any treatment. If the murmurs are due to pregnancy, dehydration or anemia, the murmur will disappear as the condition is treated. For those with abnormal heart murmurs and a heart defect, some type of treatment may be required. This may include: Medications: Some individuals may require medications to - remove the excess fluid from the body - control the blood pressure - to help the heart beat stronger - control the heart rhythm and rate - antibiotics if there is an infection of the heart Surgery: For those who have a murmur from a structural defect of the heart, surgery may be an option. Today, most open heart surgery is pretty fairly routine (unless you go to an incompetent surgeon- of which there are many). The types of surgery may include: - repair or replace the defective heart valve - close the hole in the heart - enlarge the narrowed vessels - reconstruct newer blood vessels Antibiotics: Sometimes a murmur may be due to a leaky valve or a heart defect. In all such cases, one should receive antibiotic prophylaxis before undergoing any procedure. Even simple tooth extraction can be hazardous if the antibiotics are not taken before the procedure. All leaky valves are very prone to infection and it is important to discuss this with your doctor.

Many normal children and adults have heart murmurs, but not all of these require immediate referral to a heart specialist. However, in any individual with symptoms or signs of heart disease and an associated murmur, a consult with a heart doctor is a must. Missing an innocent murmur in a healthy individual may be of no consequence but missing a murmur in an individual with a heart defect can lead to serious consequence- both for the physician and the patient.