Other Causes of Pulmonary Hypertension

Patients with connective tissue disease may present with Group I Pulmonary Arterial Hypertension and have no associated clinical signs of their underlying disorder. This is especially true in patients who have scleroderma or the CREST syndrome, a mnemonic for calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly and telangiectasia. Serologic studies to look for any nuclear antibodies are required to make the diagnosis. It should be noted that Raynaud's phenomenon, often seen in patients with collagen vascular disease is not a part of the syndrome of idiopathic pulmonary arterial hypertension.

Patients with cirrhosis and portal hypertension may develop Group I Pulmonary Arterial Hypertension. These patients may present without any clinical features of active liver disease. The diagnosis requires liver function studies including liver enzymes, serum albumin and prothrombin time.

Patients with left-to-right cardiovascular shunts may develop Group I Pulmonary Arterial Hypertension. When this occurs, reversal of the shunt to right-to-left will usually lead to cyanosis and clubbing. Patients with an atrial septal defect may have no history of a murmur or symptoms as a child or young adult. Pulmonary hypertension is a rare late finding that usually occurs after the third decade. Laboratory studies necessary to make the diagnosis include an echocardiogram to look for the defect and evidence of right-to-left shunting and cardiac catheterization, especially if surgery is to be performed.

Some patients with left-sided heart disease and pulmonary hypertension, Group II, may present with dyspnea and rales. Laboratory studies necessary to make the diagnosis include chest X ray, echocardiography and/or other imaging studies, such as cardiac magnetic resonance imaging.

Some patients with lung disease and/or hypoxemia, Group III, present with pulmonary hypertension as the dominant clinical feature and dyspnea as the prominent symptom. While rales are often heard on auscultation, they may not be present in some individuals. Laboratory studies necessary to make the diagnosis include a chest X ray and pulmonary function testing. If these are consistent with interstitial lung disease, a high resolution chest CT scan is required.

Some patients with pulmonary hypertension associated with chronic thromboembolic disease, Group IV, may present with dyspnea. Laboratory studies necessary to make the diagnosis may include ventilation perfusion scanning and chest CT angiography.