Auscultation of Common Abnormal Heart Sounds
Listen to Heart Sounds Here!
http://depts.washington.edu/physdx/heart/demo.html
Murmurs:
Grading
- Grade I – Heard in a quiet room by an expert examiner
- Grade II – Heard by most examiners
- Grade III – Loud murmur without thrill
- Grade IV – Loud murmur with a thrill
- Grade V – Thrill with a very loud murmur audible with stethoscope placed lightly over the chest
- Grade VI – Thrill with a very loud murmur audible even with the stethoscope slightly away from the chest
Aortic Stenosis
- heard best at the right upper sternal border
- radiates to the carotid arteries
- sounds like a harsh, high-pitched systolic crescendo-decrescendo murmur (while the ventricles are contracting)
- normal S1 and narrow split or normal S2 (due to delayed aortic valve closure)
Mitral Regurgitation
- heard best at the apex of the heart (4th-5th left intercostal space, midclavicular)
- radiates to the axilla and/or the base of the heart
- sounds like a blowing, high-pitched holosystolic murmur that stays the same throughout (plateau; blood moves backward across the mitral valve as the ventricles contract)
- muffled S1 and widely split S2
Extra Heart Sounds:
S3
- if coming from the left ventricle, heard best at the apex with the patient in the left lateral decubitus position (lying on his/her left side) while holding breath at the end of expiration
- if coming from the right ventricle, heard best at the left lower sternal border or the xiphoid while the patient is supine
- heard best with the bell of the stethoscope
- sounds like a low-pitched beat in early diastole (while the ventricles are filling with blood from the atria)
- may be due to excess blood moving from the atria into the ventricles (volume overload) or a stiff ventricle (overfilled and/or hypertrophied ventricle)
- can be normal in those who are younger than 40 years old; if > 40 years old, check for enlarged ventricle(s)
- differentiate from normal splitting of heart sounds, which are HIGH-PITCHED and heard best with the DIAPHRAGM of the stethoscope
S4
- if coming from the left ventricle, heard best at the apex with the patient in the left lateral decubitus position (lying on his/her left side) while holding breath at the end of expiration
- if coming from the right ventricle, heard best at the left lower sternal border or the xiphoid while the patient is supine
- heard best with the bell of the stethoscope
- sounds like a low-intensity beat late in diastole
- may be due to decreased compliance of ventricle (as in S3) or forceful contraction of atria (“atrial kick”)
- will not be heard if atrial fibrillation or atrial flutter present
- differentiate from normal splitting of heart sounds, which are HIGH-PITCHED and heard best with the DIAPHRAGM of the stethoscope
Source (to learn more about heart sounds):
Mangla, A. (2014, April 24). Heart sounds. Medscape. Retrieved from http://emedicine.medscape.com/article/1894036-overview
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