Uncomplicated pneumopericardium is not frequently met with, for the affection is usually associated with fluid accumulations, and with the percussion resonance there will be other phenomena presently to be noted. On auscultation the heart sounds have a ringing character.
Pneumo-hydropericardium.
This, too, is a disorder of great rarity, and may be considered one of the curiosities of clinical experience. It is indeed an unsolved problem whether pneumo-hydropericardium ever exists except as a result of the ingress of air from without the body or from an adjacent organ through an opening made into the pericardium. Nearly all the cases that have been reported have upon careful investigation exhibited the evidence of perforation either by mechanical means or by ulcerative action.
The SYMPTOMS of the accumulation of gas or air in the pericardium associated with fluid are largely, if not entirely, the same as in pericarditis with effusion. There is the same sense of oppression in the chest, irregular rapid action of the heart, pain in the præcordial region, difficulty of breathing, and there may be febrile excitement.
These symptoms are thus not of much diagnostic value unless accompanied by the physical signs indicative of the disease. They are præcordial bulging, diminished cardiac impulse, and the sounds elicited by percussion and auscultation which show the presence of air and fluid. On percussion we have clear or tympanitic resonance in the cardiac region, somewhat modified, especially at the lower parts, by the dulness from the fluid, and very changeable with the altering postures of the patient. On auscultation the signs are variable. Laennec placed great reliance on fluctuation audible with the action of the heart and on deep inspiration, the heart sounds being heard at a distance. We may also find what has been called a splashing or a churning splash, or the sounds of the heart may be extremely ringing, and even metallic; there may be a combination of sounds, as in the case recorded by Stokes,37 where "they were not the rasping sounds of indurated lymph or the leather creak of Collin, nor those proceeding from pericarditis with valvular murmurs, but a mixture of various attrition murmurs with a large crepitating and gurgling sound, while to all these phenomena was added a distinct metallic character." In the case recorded by John F. Meigs38 loud splashing or churning sounds were audible three or four feet distant from the heart; while Reynier39 directs particular attention to an intermittent sound, at first metallic, and resembling a water-wheel.
37 Diseases of the Heart and Aorta.
38 Amer. Journ. Med. Sci., Jan., 1875.
39 Arch. génér. de Méd., Mai, 1880.
In point of DIAGNOSIS we must be very careful not to confound the resonance transmitted from a distended stomach to the cardiac region with pneumo-hydropericardium. The rapid action of the heart and shortness of breath due to the gastric distension may further mislead, and the heart sounds may become sharply defined—the second more ringing. I have several times been called upon for an opinion in cases of the kind which were supposed to be pneumo-hydropericardium. Cavities situated near the heart may also present transmitted cardiac sounds of metallic timbre.40
40 Bauer, Diseases of the Pericardium.