Cystic fibrosis is the most common fatal inherited disease of Caucasians. At present, cystic fibrosis accounts for most cases of chronic progressive pulmonary disease and for many other clinical features in the first three decades of life. Thus, it is a challenge to both pediatricians and internists, particularly chest physicians. The diagnosis is based on the triad of chronic obstructive pulmonary disease, pancreatic insufficiency, and increased levels of electrolytes in the sweat. The cardinal test for confirmation of the diagnosis is the "sweat test," which is an excellent discriminant for cystic fibrosis, even in adults. Ancillary features of cystic fibrosis may be of diagnostic assistance (eg, nasal polyposis, Pseudomonas aeruginosa in sputum, azoospermia, and others). Treatment of the pulmonary disease must be emphasized. Choice of antibiotics should be based on the results of sputum culture, but P aeruginosa is the most common pathogen. Removal of secretions by regular postural drainage and percussion is an integral part of the program. Pneumothorax, massive hemoptysis, cor pulmonale, and other complications may be encountered. Sinusitis is almost universal, and nasal polyposis is frequently present. Pancreatic insufficiency occurs in over 80 percent of the patients with cystic fibrosis and may result in intestinal malabsorption. Massive salt loss through the sweat in hot weather, a distinctive type of biliary cirrhosis without jaundice, gallbladder abnormalities, cholelithiasis, and diabetes mellitus also may be found. Of special importance are intestinal obstructive complications (meconium ileus in newborn infants with cystic fibrosis and intestinal obstruction due to fecal accumulation or intussusception in adults). Azoospermia is present in 95 percent of men and there is reduced fertility in women; however, pregnancy does occur in cystic fibrosis. This chronic and ultimately fatal disease produces a predictable set of psychosocial complications.

Pulmonary hypertension may occur as a primary disorder of the pulmonary vasculature or secondary to a variety of cardiac or pulmonary diseases. The reversibility of pulmonary hypertension is dependent on the relative contribution of reversible vasoconstriction and irreversible structural changes in the pulmonary vessels. Despite recent advances in the understanding of pulmonary vascular physiology, knowledge of the pathogenesis and natural history of pulmonary hypertension has been limited by an inability to measure pulmonary arterial pressure noninvasively. Thus, when patients have symptoms or signs of pulmonary hypertension, the disease is usually at an advanced stage. It is possible that early in the course of hypoxic pulmonary disease, pulmonary hypertension may be protective in optimizing matching of ventilation and perfusion. It is not known at what point pulmonary hypertension per se becomes harmful. Certainly, treatment directed at underlying cardiac or pulmonary disease is indicated. It also seems reasonable to treat severe degrees of pulmonary hypertension complicated by right ventricular dysfunction. With the advent of orally effective pulmonary vasodilators, direct treatment of primary and secondary pulmonary hypertension may now be possible. Hopefully, with careful clinical evaluation of the response to vasodilator therapy, we will learn whether these drugs prolong life and reduce morbidity in primary and secondary pulmonary hypertension. In the meantime, much more information is needed regarding the mechanisms of acute pulmonary vasoconstriction and sustained pulmonary hypertension. In addition, a means of early identification of patients with mild hypertension is needed.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliable aortic valve replacement was one of the most significant advances in the treatment of cardiac disease in this century. It allowed, for the first time, a reliable and reproducible method to palliate the symptoms of aortic stenosis and regurgitation and significantly improved longterm survival over that after medical treatment. Sporadic attempts at aortic valve replacement had been conducted in the late 1950s, but the pioneering work of Harken et al, followed by the final development of a reliable device by Starr, Edwards, and coworkers, opened the era of successful aortic valve replacement. We review the prognosis of patients following aortic valve replacement with aortic stenosis and regurgitation with and without associated procedures and evaluate the various types of bioprosthetic and prosthetic valves in current use, presenting advantages and disadvantages of each type of replacement device.

Although the lower respiratory tract is frequently exposed to injurious agents, the lung does possess some ability to effect repair and thus restore the damaged alveolar wall to normal; however, in some circumstances, normal repair is not possible. The result is often a markedly deranged alveolus, with improper proportions of epithelial cells (eg, relatively more cuboidal type-2-like cells), a loss of endothelial cells or migration of endothelial cells into improper locations, and a proliferation of interstitial fibroblasts with an accompanying deposition of a collagenous extracellular matrix (ie, fibrosis). Although the development of "fibrosis" is frequently thought to be a form of attempted "repair" of an injured alveolar wall, this concept is not clearly established; it is possible that the expansion of fibroblastic numbers in the alveolar wall is part of the disease process itself, resulting from alveolar macrophagic activation, rather than an attempt by the macrophage to "repair" an injured alveolar wall. Thus, it is not known if the development of fibrosis represents "healing" and thus is beneficial (as a localized scar "heals" a localized incision in the skin) or whether it represents part of the disease process itself. The distinction is important, as it is unclear whether therapy should be directed against the development of fibrosis per se. If fibroblastic expansion and deposition of the connective tissue products of these fibroblasts are a useful form of repair, prevention of this process may cause future loss of pulmonary function. Alternatively, if "fibrosis" compromises pulmonary function (particularly decreased compliance), prevention of fibrosis might be beneficial. It is apparent, therefore, that what is needed is an understanding of the processes that lead to alveolar parenchymal cellular repair and how such processes might be manipulated for the benefit of the patient.