Lung fibrosis causes early impairment in gas exchange leading to exertional dyspnea. Pleurisy and pericarditis with effusion may occur. Lung involvement generally progresses indolently, with substantial individual variability. Cardiac arrhythmias, conduction disturbances, and other ECG abnormalities are common. Heart failure may develop because of pulmonary hypertension and secondary cor pulmonale or because of diffuse fibrous replacement of cardiac muscle.
Heart failure tends to be chronic and difficult to treat.
Severe renal disease may occur as a consequence of intimal hyperplasia of interlobular and arcuate arteries and usually is heralded by the abrupt onset of accelerated or malignant hypertension. If untreated, renal insufficiency rapidly progresses, becomes irreversible, and is lethal within a few months. Laboratory Findings Full-blown systemic sclerosis is readily diagnosed on clinical grounds. The nonspecific antibody and HLA typing are largely of research interest. The ANA often show an antinucleolar pattern.