Secondary pulmonary hypertension--diagnosis and management

Secondary pulmonary hypertension (SPHtn) is generally attributable to abnormalities in structure or function of the heart or lung parenchyma. While often defined as a physiologic parameter, pulmonary hypertension (PHtn) can be a major contributor to death and disability in cardiopulmonary diseases. Both detection and management are a challenge. We will review the pathophysiology, diagnostic tools, and treatment strategies in SPHtn with an emphasis on cor pulmonale associated with chronic obstructive pulmonary disease (COPD), pulmonary vasculopathies, and pulmonary embolus. The pathophysiology and common etiologies of SPHtn can be divided into three major categories: (1) elevated pulmonary venous pressure (LV failure and mitral valve disease), (2) pulmonary vascular occlusive disease with or without pulmonary parenchymal disease (pulmonary emboli, COPD, connective tissue diseases), and (3) hypoxemia (sleep apnea). The echo-Doppler is a simple cost-effective tool for detecting PHtn, evaluating right ventricular function, and distinguishing common etiologies such as abnormal systolic and diastolic left ventricular function and mitral valve disease. The ventilation-perfusion radionuclide scan can be used to exclude thromboembolic PHtn, but a helical computer tomography with contrast or pulmonary angiography are necessary to distinguish patients that may benefit from a pulmonary thromboendarterectomy. The six minute walk oxygen saturation test is useful as a quantitative measure of functional capacity, prognosis, response to therapy, and oxygen requirement. Treatment strategies in cor pulmonale are tailored to the specific diagnosis, but generally include proper nutrition, exercise, oxygen supplementation, medications such as digoxin, diuretics, anti-coagulation, and pulmonary vasodilator therapy in selected patients.