She developed a deep venous thrombosis following cardiac catheterization and responded to anticoagulation with warfarin. The patient's overall condition improved significantly and she was discharged home to be followed as an outpatient. Six months later she was readmitted with a history of swelling of the legs, dyspnea, weakness and cough. In spite of aggressive support, the patient remained severely ill and suffered a cardiac arrest from which she could not be revived. For religious reasons, no autopsy could be obtained.
Section shows fragments of lung parenchyma.
The pulmonary vessel walls show mild cellular proliferation with fibrous thickening and luminal occlusion or narrowing consistent with vasculitis. However, a majority of these patients are noted to have significant parenchymal involvement. In some patients, the degree of pulmonary hypertension cannot be explained by the severity of parenchymal involvement and mechanisms other than interstitial lung fibrosis are involved in its genesis.7 P. Nicod and associates6 analyzed the safety of doing pulmonary angiography in 67 consecutive patients with moderate to severe primary pulmonary hypertension or hypertension secondary to chronic thromboembolism. They concluded that pulmonary angiography can be done safely despite the presence of severe pulmonary hypertension and right ventricular failure and that the procedure leads to identification of chronic major vessel thromboembolism which may be treated by thrombo-endarterectomy. A restrictive defect on pulmonary function test was also unable to explain the severity of pulmonary hypertension, tricuspid incompetence and right-sided heart failure in our patient.