Hydrothorax in Heart Failure.

The term " hydrothorax" was applied to clear, non-purulent, pleural effusions before percussion and auscultation were practised and before the signs of heart disease were known. The diagnosis then depended entirely on symptoms, and MacLean (1810) in an early treatise on hydrothorax wrote as follows: " when respiration is considerably impeded, especially on motion, in a horizontal posture, or on ascending an acclivity, when the countenance is at the same time pale and sallow, assumes a leaden or livid hue; the urine small in quantity, high coloured, and, on cooling, deposits a reddish or pink-coloured sediment; the pulse irregular or intermitting; the feet, ankles, or hands swell and are colder than natural; and the patient is suddenly roused from sleep by a sense of suffocation or extreme anxiety about the praecordia, attended with palpitation; the most superficial observer will have no doubt of the presence of a watery fluid in some of the cavities of the chest, and that the person thus affected labours under the disease termed hydrothorax, or dropsy of the chest." Morgagni (1761) described the association of hydrothorax with heart disease post-mortem and thought that, of the two, the heart lesion was more likely to be the primary condition ; but it was Corvisart (1818) who first really distinguished between hydrothorax consecutive to heart failure and idiopathic or essential hydrothorax, i.e. pleurisy with effusion. He pointed out that cardiac hydrothorax was always associated with ascites and general anasarca Laennec (1826), though he gave an admirable and separate account of pleurisy with effusion, still recognized the two varieties of hydrothorax described by his teacher. Idiopathic hydrothorax was unilateral; symptomatic or secondary hydrothorax was bilateral and usually a terminal condition. He seems to have regarded the absence of adhesions and false membrane as the essential criterion of hydrothorax, though he admitted that the distinction from chronic pleurisy was often as difficult in the cadaver as during life, and mentioned inflammatory hydropsies as having been described. Comte (1822), in his treatise on hydro-thorax, does not appear to have recognized heart disease as the cause, though signs of heart failure were-often mentioned-and digitalis was advocated in treatment. He regarded the palpitation and irregular pulse as due to pressure 93