Ectopia of the heart, i.e., congenital malformation in which the heart is displaced from its normal position and thrust sometimes completely beyond the thoracic cavity, is not very rare. The heart may be well developed, but it is not enclosed by the thoracic walls when the thoracic cavity closes during the first stages of embryonic life. The sternum, which is cartilaginous and becomes ossified only at a later period, remains fissured along the median line, and the fissure, usually of oval form and with rounded margins, surrounds the auricles and the vessels at the base of the heart. The ventricles form a hernia projecting beyond the thorax, which then only contains the two pleural sacs and a complete mediastinal partition. The pericardium remains undeveloped.
Despite this malformation, the embryo develops. The fœtus may in due season be brought forth living, but as a rule death occurs in a few hours.
The diagnosis is easy, but this malformation cannot be treated. All that can be done is to protect the ectopiated organ against external violence in cases where the young creature is born alive.
CHAPTER II.
PERICARDITIS.
Pericarditis consists in inflammation of the pericardial sac. It is attributable to different causes, varying in importance and in causation.
Specific pericarditis may be produced by the tubercle bacillus, or it may develop during an attack of contagious peripneumonia. Tuberculous or peripneumonic forms of pericarditis as a rule form only complications of chronic pulmonary tuberculosis or peripneumonia. They are very rarely primary in character, and, like the allied forms of pleurisy, assume a vegetative and adhesive form in tuberculous cases.
Moussu has never seen the true exudative form either in acute or chronic tuberculosis, but only vegetative and caseous forms.
Simple acute pericarditis. Cases of simple acute exudative pericarditis have been described, and have been referred to chills, wounds, or injuries in the region of the heart, and in a few cases to the rheumatic diathesis.
Such forms of pericarditis may occur, but probably are very rare, for Moussu has seen but two cases. As the symptoms correspond exactly to those of exudative pericarditis produced by a foreign body, it is unnecessary to describe them specially.
The only important detail to bear in mind with this disease is the possibility of cure by suitable treatment, such as the application of stimulants or vesicants to the cardiac zone, the administration of salicylate of soda or diuretics, and complete rest.