Heart murmurs are abnormal sounds that can be heard as swishing or whooshing noises, caused by turbulent blood flowing across the heart valve. They can occur due to an abnormal heart valve or other conditions that cause the heart to beat faster and handle more blood at a faster rate. Heart murmurs may be present from birth (congenital) or develop later in life and can exist without any medical or heart conditions. Childhood murmurs and pregnancy are two common examples.
The heart has four chambers separated by valves that regulate the flow of blood in and out of each chamber. Normal valves prevent blood from flowing in the wrong direction in the heart, and a healthy and normal heart produces a "lub-dub" sound during each heartbeat. The "lub" sound (systolic sound) occurs during the contraction of the heart when the mitral and tricuspid valves close, and the "dub" sound (diastolic sound) occurs during the relaxation of the heart when the aortic and pulmonic valves close.
A heart murmur is an additional sound heard during a heartbeat, like a "whooshing" sound caused by turbulent blood flow between the heart valves.
Abnormal heart murmurs may cause various signs and symptoms, depending on the cause of the murmur. These may include a blue appearance of skin on the fingertips and lips, sudden weight gain or swelling, shortness of breath, chronic cough, an enlarged liver, enlarged veins, poor appetite and failure to grow normally, heavy sweating with little or no activity, chest pain, dizziness, fainting, and fatigue.
Heart murmurs can be caused by various health conditions such as anemia, high blood pressure, thyroid problems, and fever. They can also occur during certain events in the heartbeat, such as when the heart fills with blood (diastolic murmur), when it empties (systolic murmur), or throughout the heartbeat (continuous murmur).
Heart murmurs can be classified into two types: innocent heart murmurs and abnormal heart murmurs. Innocent heart murmurs occur in individuals with a normal heart structure and are often seen in newborns and children. They can be caused by factors such as physical activity, pregnancy, fever, lack of healthy red blood cells, excessive thyroid hormone, or phases of rapid growth. Innocent heart murmurs may disappear over time or may persist without causing any further health issues.
On the other hand, abnormal heart murmurs are commonly caused by structural problems of the heart or congenital heart defects in children. Common congenital defects that cause heart murmurs include holes in the heart and cardiac shunts. In older children and adults, heart murmurs may result from infections or conditions that damage the heart's structures, such as valve calcification, endocarditis, or rheumatic fever. These conditions can interfere with normal blood flow through the heart and may lead to serious complications.
To determine the cause of a heart murmur, a doctor may suggest several tests. These tests include an electrocardiogram (ECG), which measures the electrical activity of the heart, a chest X-ray to check for heart or valve enlargement or other pathology, and an echocardiogram, which uses sound waves to map the structure of the heart.
While harmless heart murmurs don't require any treatment, some types of heart valve diseases may require medication to prevent blood clots, control irregular heartbeat or palpitations, and reduce blood pressure levels. In some cases, diuretics may be prescribed to remove excess salt and water from the body, making it easier for the heart to pump. If the heart defect is present from birth, surgery may be necessary to correct it. Surgical procedures may also be recommended to correct certain types of heart valve disease.
Several medical conditions can significantly increase the risk of heart murmurs, such as cardiomyopathy, endocarditis, hypereosinophilic syndrome, autoimmune disorders, carcinoid syndrome, heart valve disease, hypertension, pulmonary hypertension, history of rheumatic fever, and hyperthyroidism.