From the Guidelines
The murmur associated with aortic stenosis is typically a loud, late-peaking systolic ejection murmur that radiates to the carotids.
Characteristics of the Murmur
- The murmur is usually grade 4/6 in severity and is often described as crescendo-decrescendo in configuration 1.
- It starts shortly after the first heart sound (S1) and peaks late in systole, with the peak intensity occurring near the end of systole 1.
- The murmur radiates to the carotid arteries and may also be heard at the apex, especially in older patients or those with concomitant mitral regurgitation 1.
- A single or paradoxically split second heart sound (S2) is often associated with severe aortic stenosis, and a delayed and diminished carotid upstroke may also be present 1.
Diagnostic Considerations
- Echocardiography is recommended for the diagnosis and assessment of aortic stenosis severity, as well as for the evaluation of left ventricular wall thickness, size, and function 1.
- The physical examination findings, including the characteristics of the murmur, should be integrated with the echocardiographic results to determine the severity of aortic stenosis 1.
- A meticulous history and physical examination are essential in establishing a pre-test probability of the severity of aortic stenosis, which can help guide the interpretation of echocardiographic results 1.
From the Research
Characteristics of the Murmur
- The murmur associated with aortic stenosis is a systolic ejection murmur, with prolonged duration and late peaking being characteristic of severe aortic stenosis 2
- The loudness of the murmur correlates with peak momentum transfer and body size, making loud murmurs less reliable in predicting severe disease in larger patients 3
- The murmur is typically heard at the second right intercostal space and may radiate to the neck 4, 5
- The presence of a murmur over the right clavicle is a significant finding, with its absence ruling out aortic stenosis and its presence, combined with other associated findings, ruling in aortic stenosis 4
Associated Findings
- Slow carotid artery upstroke and reduced carotid artery volume are associated findings that can help rule in aortic stenosis 4
- Reduced intensity of the second heart sound is also an associated finding 4
- The presence of three or four associated findings, including maximal murmur intensity at the second right intercostal space, can rule in aortic stenosis 4
Differentiation from Other Conditions
- Functional aortic systolic murmurs in the elderly can be distinguished from aortic stenosis by the absence of a thrill during systole, brief duration, and proto-meso-systolic position of the murmur, as well as the absence of a diastolic murmur and normal carotid arteriogram 5