Relationship of pulmonary artery diastolic and pulmonary artery wedge pressures in mitral stenosis.

Resting and exercise hemodynamic studies were performed in 22 patients with mitral stenosis (14 men and 19 women; average age, 25 years) in normal sinus rhythm with normal pulmonary vascular resistances. A normal pulmonary vascular resistance was assumed when the resting pressure gradient between the pulmonary artery diastolic and mean pulmonary artery wedge pressures was 5 mm. Hg or less. A satisfactory correlation existed between the pulmonary artery wedge and pulmonary artery diastolic pressures at rest (r equals 0.9017) and during exercise (r equals 0.8670). A method of predicting pulmonary artery wedge pressure from pulmonary artery diastolic pressure during exercise was formulated. The correlation between the predicted and measured exercise pulmonary artery wedge pressures was very close (r equals 0.9561). It is suggested that during exercise the pulmonary artery diastolic pressure can be modified as above and substituted for mean pulmonary artery wedge pressure if the resting gradient between pulmonary artery wedge and pulmonary artery diastolic pressure is known.