A heart murmur is an abnormal, extra sound during the heartbeat cycle made byblood moving through the heart and its valves. It is detected by the doctor's examination using a stethoscope.
A heart beating normally makes two sounds: "lubb" when the valves in one partof the heart close, and "dupp" when other valves close. A heart murmur is aseries of vibratory sounds made by turbulent blood flow. The sounds last longer than normal heart sounds and can be heard between the normal sounds of theheart.
Heart murmurs are common in children, but they can also result from heart orvalve defects. Nearly two thirds of heart murmurs in children are produced bya normal heart and are harmless. This type of heart murmur is usually calledan "innocent" murmur. Innocent heart murmurs are typically very faint, intermittent, and occur in a small area of the chest. "Pathologic" heart murmurs involve disease and may indicate the presence of a serious heart defect. Theyare louder, continual, and may be accompanied by a click or gallop.
Some heart murmurs are continually present; others happen only when the heartis working harder than usual, including during exercise or certain types of illness.
Innocent heart murmurs are caused by blood flowing through the chambers and valves of the heart or the blood vessels near the heart. Sometimes anxiety, stress, fever, anemia, overactive thyroid, and pregnancy will cause innocent murmurs that can be heard by a physician using a stethoscope. Pathologic heart murmurs, however, are caused by structural problems of the heart. These include defective heart valves or holes in the walls of the heart. Valve problems are more common. Valves that do not open completely cause blood to flow through a smaller opening than normal, while those that do not close properly may cause blood to go back through the valve. A holein the wall between the left and right sides of the heart, called a septal defect, can cause heart murmurs. Some septal defects close on their own; othersrequire surgery to prevent progressive damage to the heart.
Symptoms of heart murmurs differ depending on the cause. Innocent heart murmurs and those which do not impair the function of the heart have no symptoms.Murmurs due to severe abnormalities of a heart valve may cause shortness of breath, dizziness, chest pains, palpitations, and lung congestion.
Heart murmurs can be heard when a physician listens to the heart through a stethoscope during a regular check-up. Very loud heart murmurs and those with clicks or extra heart sounds should be evaluated further. Infants with heart murmurs who do not thrive, eat, or breath properly and older children who loseconsciousness suddenly or are intolerant to exercise should also be evaluated further. If the murmur sounds suspicious, the physician may order a chest x ray, an electrocardiogram, and an echocardiogram.
An electrocardiogram (ECG) shows the heart's activity and may reveal muscle thickening, damage, or a lack of oxygen. Electrodes covered with conducting jelly are placed on the patient's chest, arms, and legs. They send impulses ofthe heart's activity to a recorder which traces them on paper. The test takesabout 10 minutes and is commonly performed in the doctor's office. An exercise ECG (a stress test conducted on a treadmill or stationary bicycle) can reveal additional information.
An echocardiogram (cardiac ultrasound), may be ordered to identify a structural problem that is causing the heart murmur. An echocardiogram uses sound waves to create an image of the heart's chambers and valves. The technician applies gel to a hand-held transducer, then presses it against the patient's chest. The sound waves are converted into an image that can be displayed on a monitor. Performed in a cardiology outpatient diagnostic laboratory, the test takes 30 minutes to an hour.
Innocent heart murmurs do not affect the patient's health and require no treatment. Heart murmurs due to septal defects may require surgery. Those due tovalvular defects may require antibiotics to prevent infection during certainsurgical or dental procedures. Severely damaged or diseased valves can be repaired or replaced through surgery.
Most children with innocent heart murmurs grow out of them by the time they reach adulthood. Severe causes of heart murmurs may progress to severe symptoms and death.
If the heart murmur is innocent, heart activity can be supported using the herb hawthorn (Crataegus laevigata or C. oxyacantha) or coenzymeQ10. These remedies improve heart contractility and the heart's ability to use oxygen. If the murmur originates in the valves, herbs that act like antibiotics may be considered, as well as options that build resistance to infection.