“…Opie (1955). We have found in the literature eleven clinically described cases of systemic sclerosis with pulmonary hypertension verified by heart catheterization: Table IV, overleaf (Spain and Thomas, 1950;Austrian, McClement, Renzetti, Donald, Riley, and Cournand, 1951;Foss, 1954;Ellman and Cudkowicz, 1954;Bauer, 1955;Opie, 1955;Fischer and Hansen, 1956;Castleman and Kibbee, 1960;Soulie, Acar, Joly, Carlotti, Bernard, Azhrad, and Casillon du Perron, 1961;Pace, Decker, and Martin, 1963;Tourniaire, Blum, Tarlulier, and Deyrieux, 1964). As with the morbid anatomical and physiological studies, three groups may be discerned:…”