A heart murmur is an extra sound which occurs between heartbeats and can generally be detected with a stethoscope. Murmurs are classified as diastolic, systolic, and continuous, depending upon when they happen in the heartbeat cycle. A systolic heart murmur occurs when the muscles contract, pushing the blood out of the heart. It begins before or during the first sound of the heartbeat and ends before or during the second sound.
The majority of heart murmurs are innocent and many children are diagnosed with a murmur at some time in their life. Murmurs can also be caused by factors such as high blood pressure, anemia, pregnancy, fevers and an overactive thyroid. Most of these murmurs disappear on their own, and even if they remain, do not require any treatment.
A systolic heart murmur may be either innocent or abnormal. A routine exam with a stethoscope can usually detect the difference. When a murmur is present, the doctor will check the length of the murmur, when and where it occurs and if it has a high, medium, or low pitch. He will also see if the sound can be heard in the neck and back as well as the chest, and if a change in patient’s position affects the murmur. The exam will also include constructing a patient history and looking for any additional signs of heart disease, such as blueness of skin, shortness of breath, dizziness and fainting.
If an abnormal murmur appears to be present, the patient will generally be referred to a cardiologist. Additional tests, such as an electrocardiogram (EKG) and echocardiography are used to confirm the initial diagnosis and determine what is causing the murmur. An EKG records electrical activity of the heart and shows the speed and rhythm of the heartbeat. Echocardiography uses sound waves to create a picture of the heart revealing how the valves and chambers are working. Treatment of an abnormal murmur does not usually involve treating the murmur itself, but the underlying physical cause.
The doctor will grade the murmur on a scale of one to six, depending upon its noise level. A 1/6 murmur is faint while a 6/6 murmur is very loud. A systolic heart murmur is classified as an ejection murmur, which comes from the valves and surrounding structures, or a regurgitant murmur which occurs when the blood flows from the high pressure chamber to the low pressure chamber of the heart.
A systolic heart murmur can be further classified as functional or organic. A functional murmur is found in a heart with no abnormalities and is generally innocent. Functional murmurs which are caused by physical conditions such as anemia, pregnancy, thyroid malfunctions or high blood pressure tend to disappear once the health issue has been resolved. An organic systolic heart murmur is the result of structural defects in the heart or major vessels. Abnormal heart murmurs in children are generally related to a congenital heart defect; in adults they are usually caused by heart valve problems related to age, infection or disease.