What is a heart murmur?
A heart murmur is an abnormal sound that the heart produces when blood flowing in or around it is turbulent enough to be heard.
Often described as a whoosh or swish, it can be faint or loud, although it can generally only be heard with a stethoscope.
What types of heart murmurs are there?
Murmurs can be physiological or pathological.
A physiologic murmur is usually benign or ‘innocent’ and occurs due to conditions not related to the heart. These are often detected in healthy children during routine physical examinations.
Pathologic murmurs occur due to structural problems like ventricular and atrial septal defects (holes between the heart’s chambers), tract abnormalities, patent ductus arteriosus, and heart valve disorders, etc. These need to be evaluated by a physician, so that the cause may be determined and treated.
Innocent murmurs are also known as flow murmurs, functional heart murmurs, venous hums, vibratory murmurs, or Still’s murmurs, after Dr. George Frederic Still.
How are murmurs distinguished?
Heart murmurs are categorized into groups based on when they occur in the cardiac cycle. They can be systolic (occurring during contraction of the left ventricle), diastolic (occurring when the heart relaxes between contractions), or continuous (beginning in systole and continuing through diastole).
Characteristics like location, intensity, pitch, and quality further distinguish a murmur and help to identify the cause. For instance, intensity refers to how loud the sound ranks on the levine scale, while quality denotes the type of sound produced when the heart beats, such as harsh, rumbling, blowing, or musical.
What causes a heart murmur?
Heart valve disease and congenital heart defects are often the cause, though not always.
Valve diseases due to aging, infections, and other conditions can produce murmurs, such as mitral prolapse, aortic or mitral stenosis, aortic or mitral regurgitation, and aortic sclerosis. Cardiac shunts, holes in the heart, and defects involving the heart’s walls and arteries can also cause heart murmurs.
Other causes include pregnancy, high fevers, physical activity, hyperthyroidism, and anemia.
What are the risk factors for heart murmurs?
With benign murmurs, there are no risk factors. Then, there are a number of factors that increase the likelihood of being born with conditions that may cause a non-benign heart murmur and problems, such as illnesses like rubella and diabetes during pregnancy.
Taking certain drugs and consuming alcohol when pregnant also increases the risk of being born with a murmur, as does a family history of heart defects. Hypertension, pulmonary hypertension, radiation treatments, and heart attacks or endocarditis increase the risk later on in life.
What are the signs and symptoms of a murmur?
The signs and symptoms depend on the type of heart murmur and its cause.
People with innocent murmurs do not experience symptoms, while those with a pathological murmur can experience a variety of symptoms. Common symptoms include chest pain, palpitations, and coughing, breathlessness, fainting, dizziness, fatigue, excess sweating, and weight changes.
Signs of heart disease may include a bluish tint of the skin, sudden swelling in the legs and abdomen (due to fluid buildup known as edema), enlargement of the neck veins, and more.
How are heart murmurs diagnosed?
Murmurs are often detected during routine medical check-ups or when looking for unrelated health problems. During the exam, the doctor may pick up abnormal sounds during auscultation, after which the patient will normally be referred to a specialist for further testing.
The specialist will perform a thorough physical examination to identify the cause and type of murmur. He or she may then perform various diagnostic tests to confirm the diagnosis and determine a suitable treatment, such as a chest x-ray, an electrocardiogram (EKG), and an echocardiogram.
How are murmurs treated?
Benign murmurs do not require any form of treatment. When it’s a pathological murmur, surgery, medications, and lifestyle changes may be prescribed to remedy the problem.
Surgery can be done to correct problems with the heart and its structures. Antibiotics, anticoagulants, antiarrhythmics, beta blockers, vasodilators, and diuretics can be taken to manage symptoms and prevent complications. Lifestyle changes may involve eating more healthily and exercising more regularly.
Can heart murmurs be prevented?
Not always, but yes. Murmurs can be prevented by treating underlying health problems. Once the problem is detected, measures can be taken to correct it and prevent complications.
Infections like infective endocarditis, for example, which is known to cause heart murmurs and health problems, can be prevented by practicing good oral hygiene, taking prophylactic antibiotics before dental procedures, and avoiding skin infections.