Measurement of pulmonary artery diastolic pressure from the right ventricle.

OBJECTIVES: This study evaluated the feasibility of estimating pulmonary artery end-diastolic pressure from within the right ventricle. If feasible, this could have important implications for long-term hemodynamic monitoring.
BACKGROUND: Right ventricular pressure at the time of pulmonary valve opening closely approximates pulmonary artery end-diastolic pressure. Because maximal first derivative of right ventricular pressure (dP/dt) can be easily measured, if it occurs at or very near pulmonary valve opening, right ventricular pressure at maximal right ventricular dP/dt would be an estimation of pulmonary artery end-diastolic pressure.
METHODS: In 10 patients undergoing routine right and left heart catheterization, simultaneous measurements were made using micromanometers in the right ventricle and pulmonary artery at baseline, during isometric work and Valsalva maneuver. Right ventricular pressure at maximal right ventricular dP/dt was considered the estimated pulmonary artery end-diastolic pressure and was compared with the actual pulmonary artery end-diastolic pressure.
RESULTS: At baseline, estimated and actual pulmonary artery end-diastolic pressures were (mean +/- SD) 17.7 +/- 6.6 and 16.7 +/- 6.7 mm Hg, respectively (p = NS). During isometric stress, estimated and actual pulmonary artery end-diastolic pressures were 30.4 +/- 12.7 and 28.4 +/- 10.1 mm Hg, respectively (p = NS). During Valsalva maneuvers, estimated and actual pulmonary artery end-diastolic pressures were 36.5 +/- 17.8 and 38.0 +/- 16.1 mm Hg, respectively (p = NS).
CONCLUSIONS: Although more extensive testing is necessary to evaluate validity in different physiologic and pathologic situations, it appears that right ventricular pressure at maximal right ventricular dP/dt can provide accurate estimation of pulmonary artery end-diastolic pressure.