Hamman's sign is described as a mediastinal crunch. This sound occurs from subcutaneous air, usually due to a pneumothorax. It is frequently loud with a crunchy‚ character and may be palpable.
What is a pericardial knock?
A pericardial knock is a high- or low-pitched sound that occurs during diastole in constrictive pericarditis. It is caused by the abrupt cessation of ventricular filling during early diastole due to the thickened and stiff pericardium.
Describe the auscultative findings in mitral valve prolapse.
In mild mitral valve prolapse, a mid-systolic click may be noted without a murmur.
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The click is caused by the sudden tensing of the redundant chordae or valve leaflets. In more severe cases, the presence of mitral regurgitation produces a mid-systolic murmur that commences just after the mid-systolic click. The murmur is best heard at the apex and may radiate posteriorly to the mid-axillary line. The murmur may become holosystolic in the most severe cases. Because of the decrease in left ventricular volume, the murmur becomes more intense and commences earlier with the administration of amyl nitrite, upon standing, or with the Valsalva maneuver.
Describe the murmur of mitral stenosis.
The murmur of mitral stenosis depends on the turbulence created by the flow across a narrowed mitral valve orifice. The murmur is usually low pitched in frequency, due to the relative low prescribed gradient across the mitral valve, and is best heard at the apex with the bell. The murmur is usually preceded by an opening snap in early diastole and can be accentuated by having the patient lie in the left lateral decubitus position.