[Favorable response of pulmonary hypertension in patients with chronic obstructive airway disease treated with diltiazem].

The hemodynamic response to 20 mg diltiazem i.v. was assessed at rest and during bicycle exercise in the supine position in 32 patients with pulmonary hypertension due to chronic obstructive pulmonary disease. The mean arterial pressure decreased significantly at rest by some 8% and by 2% during exercise. The heart rate fell by some 4% at rest, but remained unchanged during exercise. The cardiac index, stroke volume index and pulmonary capillary wedge pressure did not differ significantly at rest, but during exercise the cardiac index increased by 5% and the stroke volume index by 8%; pulmonary wedge pressure was not influenced by diltiazem. The systolic pulmonary artery pressure fell significantly by some 9% at rest and by 10% on maximum exercise; mean pulmonary arterial pressure decreased significantly by some 10% both at rest and during exercise. Right atrial mean pressure rose significantly on average from 4 to 6 mm Hg, while remaining unchanged during exercise. After diltiazem the total body vascular resistance fell by 8% at rest and by 6% during exercise, while pulmonary arteriolar resistance was lowered by 13% (significant) at rest and by 11% (also significant) during exercise. Decrease in pulmonary afterload was more significant in our patients than decrease in peripheral afterload. In 6 of 32 patients there was no improvement in hemodynamic data after administration of diltiazem. These results support the inclusion of calcium channel blockers in the therapeutic regimen of pulmonary hypertension due to chronic lung disease.