Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Elsevier; 2019.
Bickley LS, Szilagyi PG. Bates’ Guide to Physical Examination and History-Taking. 11th ed. Wolters Kluwer Health/Lippincott Williams & Wilkins; 2013.
Simel DL, Rennie D, Keitz SA. The Rational Clinical Examination: Evidence-Based Clinical Diagnosis. McGraw-Hill; 2009.
Walker HK, Hall WD, Hurst JW. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd ed. Butterworths; 1990.
A heart murmur occurs when laminar blood flow becomes turbulent due to:
1) Increased flow through a normal valve or vessel (in patients with hyperdynamic circulation).
2) Flow through a stenotic valve or inflow of blood into a dilated vessel (eg, in aortic aneurysms).
3) Backflow caused by valvular regurgitation.
4) Passage through an abnormal communication (eg, in ventricular septal defects).
On examination, establish the following characteristics of the murmur: area where it is the loudest (areas of auscultation: see Figure 1.15-1), systolic versus diastolic, intensity, radiation, character, and factors increasing and decreasing the loudness (dynamic auscultation). Right-sided murmurs become louder with inspiration.
The intensity of a heart murmur is graded on the Levine scale of 1 to 6:
1) Grade 1 murmur: The softest of audible murmurs; it can only be heard with significant attention.
2) Grade 2 murmur: Soft but audible immediately on placing the stethoscope on the chest.
3) Grade 3 murmur: Intermediate intensity, easily audible, similar to that of breath sounds.
4) Grade 4 murmur: Loud and accompanied by a palpable thrill.
5) Grade 5 murmur: Similar to the grade 4 murmur but loud enough to be heard with only the edge of the stethoscope touching the chest.
6) Grade 6 murmur: Audible with the stethoscope off the chest.
Note that hemodynamic changes associated with murmurs are complex, and valvular lesions may present atypically in unique circumstances and when combined with other cardiovascular abnormalities. Classic features of common murmurs: Table 1.15-1.
TablesTop
Murmur |
Loudest location and radiation |
Character |
Dynamic auscultation maneuvers |
Associations |
Systolic murmurs | ||||
AS |
Right upper sternal border; AS radiating to carotids or clavicles is more severe |
Crescendo-decrescendo (ejection) |
Increases with release phase of Valsalvaa and squatting, decreases with strain phase of Valsalva and standing |
Syncope, angina; pulsus parvus et tardus; brachioradial and carotid-apical delay; later-peaking AS and AS with absent A2 or reverse splitting S2 are more severe |
Hypertrophic obstructive cardiomyopathy |
Left sternal border |
Crescendo-decrescendo (ejection) |
Increases with strain phase of Valsalva and standing, decreases with release phase of Valsalva and squatting |
Family history of sudden cardiac death or syncope; arrhythmia; MR |
Physiologic “flow” murmurs |
Can vary depending on underlying cause, generally upper sternal border (aortic and pulmonic outflow tracts); unlike severe AS, these do not radiate |
Crescendo-decrescendo (ejection) |
Often diminish with standing and Valsalva strain phase |
High output states (eg, anemia, fever, pregnancy, thyrotoxicosis); ASD can cause flow murmur due to increased output through pulmonic valve |
MR |
Apex radiating to axilla, but sternal and posterior radiation possible depending on affected leaflet |
Typically pansystolic, although may be early, mid-, or late systolic depending on cause and chronicity |
May be increased by handgrip or squatting and decreased by standing |
Findings of LV volume overload if chronic (S3 and laterally displaced, sustained, high-amplitude apical impulse) |
Mitral valve prolapse |
Apex with variable radiation depending on affected leaflet |
Midsystolic ejection click followed by “pansystolic”-type murmur |
Decreased by handgrip and squatting, increased by Valsalva strain phase and standing; click/murmur occurs later with preload increases, earlier with decreased preload |
Elevated risk of sudden cardiac death, infective endocarditis, potentially stroke/TIA and arrhythmia |
Tricuspid regurgitation |
Lower left sternal border |
Pansystolic, although may vary due to cause and chronicity |
Increases with inspiration |
Large c-v waves in jugular veins, pulsatile liver, ascites, peripheral edema, features of pulmonary hypertension (loud P2, RV heave). Can be caused by pacemaker in RV |
Ventricular septal defect |
Left sternal border with variable radiation |
Pansystolic |
May be augmented by handgrip |
May have palpable thrill or RV heave from left-right shunt |
Diastolic murmurs | ||||
Mitral stenosis |
Over apex, heard best in left lateral decubitus position |
Opening snap followed by rumbling diastolic murmur |
Augmented by exercise |
History of rheumatic heart disease, features of PH, atrial fibrillation |
Aortic regurgitation |
Over left sternal border with patient leaning forward holding end-expiration |
Early diastolic “blowing” decrescendo murmur; late diastolic murmur called a “flint murmur” may be also present |
Augmented by handgrip |
Connective tissue disorders, bicuspid valve aortopathy; peripheral signs include wide pulse pressure, Corrigan pulse,b Duroziez sign,c Traube sign,d Hill sign,e Austin Flint murmurf |
a The Valsalva maneuver is performed by forcible exhalation against a closed glottis. The strain phase of the maneuver is the time of maximum expiration; this is a preload-reducing maneuver. The majority of heart murmurs become softer at this point, with the exception of those caused by hypertrophic cardiomyopathy with left ventricular outflow tract obstruction and mitral valve prolapse. b Corrigan pulse (water-hammer pulse) refers to a rapidly rising and falling pulse. It is often seen at the carotid but can be accentuated at the brachial or radial pulse by raising the arm. c Duroziez sign refers to a systolic and diastolic murmur heard over the femoral artery when it is compressed. d Traube sign (pistol shot) refers to loud systolic and diastolic sounds when auscultating the femoral artery. e Hill sign refers to a popliteal systolic blood pressure >20 mm Hg higher than the brachial. f The Austin Flint murmur is a low-pitched diastolic murmur occurring in mid-late diastole from functional mitral valve obstruction related to the aortic regurgitation jet directed towards the mitral leaflets. | ||||
AS, aortic stenosis; ASD, atrial septal defect; LV, left ventricle; MR, mitral regurgitation; PH, pulmonary hypertension; RV, right ventricle; TIA, transient ischemic attack. |