Pulmonary artery pressure response to exercise was assessed using contrast enhancement of tricuspid regurgitation peak velocities in 19 patients with chronic congestive heart failure. Estimated systolic pulmonary artery pressures correlated closely with invasively measured pressures at rest (r=0.82, p <0.001) and during peak exercise (r=0.86, p <0.001) at a good level of agreement (mean difference 7.3 +/- 12 mm Hg), indicating that this method provides a reliable, noninvasive approach to evaluating functional reserve in patients with chronic congestive heart failure.