Hamman's sign

The Hamman - mark ( Hamman 's sign, and Hamman 's crunch ) is a clinical sign of spontaneous mediastinal emphysema. There is an on auscultation over the heart audible gnashing - cracking, mostly systolic murmur. It can be detected in the patient about the half with spontaneous mediastinal emphysema.

The character was named after the American internists Louis Virgil Hamman, who described the character in 1939 for the first time.