Where is the murmur of aortic stenosis typically heard?

Aortic Stenosis Murmur Location

The murmur of aortic stenosis is best heard at the upper right sternal border (second right intercostal space) with radiation to the carotid arteries and apex. 1

Primary Auscultation Sites

• The characteristic location is the upper right sternal border, where the crescendo-decrescendo systolic ejection murmur originates 1
• The murmur radiates to the carotid arteries bilaterally, making this a key diagnostic feature 1
• The murmur also radiates to the apex, where it may actually be loudest despite originating at the base 1

Radiation Patterns and Clinical Significance

• Absence of radiation to the right clavicle/carotid effectively rules out aortic stenosis (negative likelihood ratio 0.05-0.10), making this the most useful finding for excluding the diagnosis 2, 3
• The apical component may be prominent enough that an ejection sound is often loudest at the apex while still radiating to the base 1
• Maximal murmur intensity at the second right intercostal space is one of the key associated findings that helps rule in aortic stenosis (positive likelihood ratio increases substantially when present with other findings) 2

Additional Auscultatory Findings

• A systolic thrill may be palpable in the suprasternal notch or at the upper right sternal border in severe cases 1
• A systolic ejection click is typically present and loudest at the apex (particularly in younger patients before significant calcification occurs) 1
• The murmur becomes louder during expiration (as with all left-sided murmurs), which helps differentiate it from right-sided pathology 1

Clinical Examination Technique

• Listen specifically over the right clavicle—if no murmur is present there, aortic stenosis is effectively ruled out (likelihood ratio 0.10) 2
• Assess for associated findings including slow carotid upstroke, decreased carotid volume, and reduced intensity of the second heart sound, as the presence of 3-4 of these findings strongly confirms aortic stenosis (positive likelihood ratio 40) 2
• Mid-to-late peak intensity of the murmur is highly specific for aortic stenosis (positive likelihood ratio 8.0-101) 3

Common Pitfalls

• The murmur may be misdiagnosed as "benign" if the ejection click is not recognized, particularly in younger patients with bicuspid aortic valve 1
• Murmur intensity alone is unreliable for assessing severity, especially in larger patients, as loudness correlates more with peak momentum transfer and body size than with stenosis severity 4
• In severe aortic stenosis with calcification, the ejection click may disappear and A2 may become soft or absent, potentially leading to underestimation of severity 1