Pulmonary IHypertension: The B6te Noire of the Diffuse Connective Tissue Diseases

The rheumatic or diffuse connective tissue diseases (CTDs) are characterized by vascular involvement. Differences in the disease pattern are largely dependent on the extent, the organ site, and the size of the blood vessels involved. From time to time, patients with a particular CTD demonstrate an especially destructive type of vascular involvement. In scleroderma (systemic sclerosis [SSc]) and in systemic lupus erythematosus, particularly since the advent of glucocorticoid and angiotensin-converting enzyme inhibitor therapy, which have improved the outlook for glomerulonephritis and hyperreninemic renal failure, respectively, pulmonary hypertension has emerged as a major vascular involvement of abrupt onset and often lethal outcome. It is thus appropriate that two publications relevant to the pulmonary vasculature in SSc appear in this issue of the Journal [1,2]. Since patients with SSc are also prone to develop interstitial lung disease (also called fibrosing alveolitis), it is important to distinguish the degree of ventilatory dysfunction in each patient, since in patients with major reductions in ventilation and with a substantial ventilation/perfusion imbalance, hypoxia at rest is common and supplemental oxygen therapy is used, often as a last resort to reduce pulmonary pressure and right heart work. In contrast, the most challenging and perhaps most treatable group of patients with pulmonary hypertension are those with relatively normal ventilation, little to no irreversible pulmonary fibrosis, and often, few signs and symptoms to alert the physician to initiate a search. The detection and the management of pulmonary hypertension require a high index of suspicion and sensitive tools in the physiologic armamentarium. It is inappropriate to review here the myriad causes of pulmonary hypertension, which range from sleep apnea to bush tea ingestion [3]. Even within the spectrum of scleroderma-like diseases, we must sort out the presence of thromboembolism,