Murmur (Volume 3): Guido Vrolix: 9781533650757: Amazon.com.

Heart Murmurs - American Heart Association



Murmur (Volume 3)

A murmur is a sound generated when blood travels through vessels or valves in a turbulent or energy-dissipating manner.  It can be an important clue to a structural abnormality of the cardiovascular system.  However, over 50% of people have murmurs during childhood, but less than one percent are associated with congenital heart disease.  Thus, the vast majority of murmurs are benign or innocent rather than pathological.  Furthermore, although imaging modalities such as echocardiograms can detect many cardiac lesions, the final diagnosis of an innocent murmur is via a physician’s clinical assessment.

It is generally accepted that a cardiac murmur has several important characteristics that need to be discerned in order to classify them and reach a diagnosis.  Most importantly, there are key differences among these characteristics that can help differentiate benign murmurs from pathologic ones.  The following features should be described and considered:

The site where the murmur originates from tends to correspond to where it is loudest or most intense.  Timing and location tend to be the most important identifying characteristics of a murmur.

Intensity is synonymous with the loudness or amplitude of a sound wave, and it is inversely related to the size of the opening or vessel that blood travels through, and directly proportional to the pressure gradient and the amount of blood flow through that opening.  It is graded on a 6-point scale:

The frequency of a murmur depends on the pressure gradient across a valve or narrowing.
Low-pitched murmurs are heard best with a bell, and high-pitched murmurs are heard best with a diaphragm.
Some frequency ranges are inaudible by the human ear, and thus palpating for thrills is another means of detecting murmurs.

Changes in position, such as squatting, sudden standing, the valsalva maneuver, and hand gripping can all influence the aforementioned characteristics of a murmur by changing the preload, afterload, and chamber size.  This is an invaluable tool because murmur characteristics often overlap, and these maneuvers can result in predictable changes.

A murmur is a sound generated when blood travels through vessels or valves in a turbulent or energy-dissipating manner.  It can be an important clue to a structural abnormality of the cardiovascular system.  However, over 50% of people have murmurs during childhood, but less than one percent are associated with congenital heart disease.  Thus, the vast majority of murmurs are benign or innocent rather than pathological.  Furthermore, although imaging modalities such as echocardiograms can detect many cardiac lesions, the final diagnosis of an innocent murmur is via a physician’s clinical assessment.

It is generally accepted that a cardiac murmur has several important characteristics that need to be discerned in order to classify them and reach a diagnosis.  Most importantly, there are key differences among these characteristics that can help differentiate benign murmurs from pathologic ones.  The following features should be described and considered:

The site where the murmur originates from tends to correspond to where it is loudest or most intense.  Timing and location tend to be the most important identifying characteristics of a murmur.

Intensity is synonymous with the loudness or amplitude of a sound wave, and it is inversely related to the size of the opening or vessel that blood travels through, and directly proportional to the pressure gradient and the amount of blood flow through that opening.  It is graded on a 6-point scale:

The frequency of a murmur depends on the pressure gradient across a valve or narrowing.
Low-pitched murmurs are heard best with a bell, and high-pitched murmurs are heard best with a diaphragm.
Some frequency ranges are inaudible by the human ear, and thus palpating for thrills is another means of detecting murmurs.

Changes in position, such as squatting, sudden standing, the valsalva maneuver, and hand gripping can all influence the aforementioned characteristics of a murmur by changing the preload, afterload, and chamber size.  This is an invaluable tool because murmur characteristics often overlap, and these maneuvers can result in predictable changes.

Leakage can increase blood volume and pressure in the area. The increased blood pressure in the left atrium can increase pressure in the veins leading from the lungs to the heart (pulmonary veins).

If regurgitation is severe enough, the heart may enlarge to maintain forward flow of blood, causing heart failure (when the heart does not pump enough blood to the body). This may produce symptoms ranging from shortness of breath during exertion, coughing, congestion around the heart and lungs, swelling of the legs and feet.

The left atrium tends to enlarge due to the extra blood volume leaking back from the ventricle. An enlarged atrium may develop a rapid and disorganized movement (a disorder called atrial fibrillation ), which reduces the heart’s ability to pump efficiently.

A fibrillating atrium is just a quivering, not a pumping, that will not allow blood to flow normally, which increases the risk for blood clots that may cause a stroke.

Treatment for mild mitral regurgitation may include anticoagulation medication . However, surgery to repair or replace is often needed.

Walk through a step-by-step interactive guide explaining your valve issue and treatment options with helpful videos, text summaries and links along the way.



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