Background. Pulmonary hypertension Group 2 (PH 2) associated with left-sided heart disease is relatively common, is associated with a poor prognosis, and unfortunately there are no proven medical treatments beyond attempts at correcting the left sided heart disease. Many PH 2 patients have evidence of vasoconstriction and increased sympathetic nervous system activity. Use of agents or procedures which produce a reversible chemical sympathectomy have not been systematically tested in PH 2.