Which sounds would be best heard using the bell end piece of the stethoscope
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Read COVID-19 guidance from NICE Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below. In this articleHeart AuscultationTypes of Heart Sounds and MurmursIn this articleWhat is heart auscultation?Auscultation of the heart is not synonymous with examination of the heart. That is not to diminish the importance or difficulty of acquiring the necessary skills. Examination of the heart starts with general inspection for cyanosis, dyspnoea, oedema or cachexia. It is followed by assessment of jugular venous pressure (JVP), examining the pulse and checking blood pressure. This includes checking the fingers for clubbing or splinter haemorrhages. Only then is it time to move to the chest and even then it is still not yet time to produce the stethoscope. The interpretation of heart murmurs in children can be especially difficult and it is discussed elsewhere in the separate Heart Murmurs in Children article. Mechanism of heart soundsHeart sounds (normal or pathological) are caused by turbulent blood flow. They include the sound of the closing heart valves. Laminar flow is silent. Turbulent flow makes a sound. A thrill is turbulence or a murmur that is so marked that it is palpable. Inspection and palpationLook at the chest.
Feel for the apex and note its character and position.
Sites for heart auscultationThe bell of the stethoscope is better for detecting lower-frequency sounds whilst the diaphragm is better for higher frequencies. The bell is usually used to listen to the mitral valve and the diaphragm at all other sites. Heart auscultation is usually performed with the patient sitting up or reclined at about 45°. Where variations are required, they will be described. Mitral area
Tricuspid area
Pulmonary area
Aortic area
The best place to hear the heart valves is not necessarily directly over the anatomical site. Heart soundsThe intensity of heart sounds and murmurs is graded as follows on Levine's scale:
Listen first for the heart sounds. They are called S1 and S2 and are traditionally described as 'lub' and 'dub' respectively. The first sound (S1) is caused by closure of the mitral and tricuspid valves and the two sounds tend to merge as one. When considered separately, the closure of the mitral and tricuspid valves is called M1 and T1 respectively. The second sound (S2) is caused by closure of the aortic and pulmonary valves. They are slightly apart with the aortic component, also called A2, slightly after the pulmonary closure called P2.
Additional heart soundsThe differentiation of 3rd sounds, 4th sounds, opening snaps and widely split S1 or S2 can be daunting.
Heart murmursNote the timing of murmurs. Establish whether systolic or diastolic. First listen to the lub dub and then get the timing. Some murmurs may obscure the heard sounds. Systolic murmurs can be innocent but are rarely so unless the patient is a child or pregnant[]. Diastolic murmurs are always pathological. Mitral murmurs
Tricuspid murmurs
Pulmonary and aortic murmursThe pulmonary and aortic valves are both best heard in the 2nd intercostal space, to the left and right respectively. This can make differentiation quite difficult. Sound from the aortic valve is often transmitted to the carotid and can be heard by placing a stethoscope over the carotid bifurcation.
Septal defects
Other heart murmurs
Heart murmurs in children
Differential diagnosisThe following is a very simple approach to the differentiation of some of the more common and simpler problems of identifying murmurs on heart auscultation:
Referral[]The National Institute for Health and Care Excellence (NICE) recommends referral for any adult with a heart murmur as follows: Referral for echocardiographyConsider an echocardiogram for adults with a murmur and no other signs or symptoms if valve disease is suspected based on:
Offer an echocardiogram to adults with a murmur if valve disease is suspected (based on the nature of the murmur, family history, age or medical history) and they have:
Referral for urgent specialist assessment or urgent echocardiographyIf valve disease is suspected (based on the nature of the murmur, family history, age or medical history):
For guidance on referral and assessment for adults with murmur and non-exertional syncope, follow the recommendations in the NICE guideline on transient loss of consciousness ('blackouts') in over-16s. For guidance on referral and assessment for adults with breathlessness but no murmur, follow the recommendations in the NICE guideline on chronic heart failure in adults. Referral to a specialist after echocardiographyMild valve disease is common and rarely progresses to become clinically significant. Offer referral to a specialist to:
For pregnant women and women considering pregnancy
ConclusionIn these days of ready access to echocardiography and even cardiac catheterisation, it is easy to forget the simple techniques of heart auscultation. Rheumatic heart disease is becoming rare these days and surgery corrects very many congenital cardiac defects, leaving no murmurs. Nevertheless the ability to use the traditional methods in the surgery is cheap, effective and very satisfying. Not all systolic murmurs need assessment by echocardiography[]. Listening to recordings of heart sounds can be a very effective way to learn to recognise them[]. The ability to recognise sounds is said to be low but can be improved with training[]. Are you protected against flu? See if you are eligible for a free NHS flu jab today. Check now Further reading and references
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The information on this page is written and peer reviewed by qualified clinicians. Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Egton Medical Information Systems Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions. Which type of sounds can be heard through the bell of the stethoscope?The bell is best for detecting lower pitch sounds, like some heart murmurs, and some bowel sounds. It is used for the detection of bruits, and for heart sounds (for a cardiac exam, you should listen with the diaphragm, and repeat with the bell).
What does the bell of the stethoscope listen for?The bell is used to detect low-frequency sounds and the diaphragm to detect high-frequency sounds.
Which sound would the nurse Auscultate with the bell of the stethoscope?The bell of the stethoscope is best for picking up bruits. The diaphragm is more attuned to relatively high-pitched sounds; the bell is more sensitive to low-pitched sounds like bruits. When using the bell, apply it lightly over the area of the body you're listening to.
What is open bell used for stethoscope?An open bell stethoscope is one in which the diaphragm is open to the atmosphere. This type of stethoscope is used for low-frequency sounds, such as those made by the human heart. A closed bell stethoscope is one in which the diaphragm is sealed to the body of the stethoscope.
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