The phonocardiogram in spontaneous interstitial emphysema of the mediastinum

Mediastinal Emphysema and Its Occurrence in Artificial Pneumoperitoneum

“…Hamman's sign (1939b), a systolic crunch due possibly to compression and displacement of the perivascular air, is heard over the precordium, in some cases without the aid of a stethoscope. Hoffman, Pobirs, and Merliss (1943), Fagin and Schwab (1946), and Small and Fremont (1951) have suggested using a phonocardiogram to differentiate this sign from the pericardial friction rub of a subserous infarction with which it may be confused. In the interpretation of the electrocardiographic tracings, which are of greater diagnostic value, the changes consequent upon the axial displacement of the heart by the subdiaphragmatic air, flattening of the S-T segment in lead II and a conspicuous Q followed by a small R and inverted T in lead III (Benatt and Berg, 1945) should not be forgotten in the rare cases of malignant emphysema complicating artificial pneumoperitoneum.…”