Objectives: The aim of this study was to demonstrate the usefulness of preload alterations in assessing left ventricular filling pressures with transmitral Doppler velocity curves.
Background: Doppler mitral inflow velocities, used to estimate left ventricular filling pressures noninvasively, are limited in predicting left ventricular filling pressures, especially in patients with normal systolic function and a "pseudonormal" mitral filling pattern.
Methods: Forty-nine patients were studied in the cardiac catheterization laboratory with simultaneous Doppler echocardiography using high fidelity catheters to compare left ventricular diastolic filling pressures (pre-A wave left ventricular pressure) and Doppler mitral inflow at baseline and during reduction of preload during the strain phase of the Valsalva maneuver (n = 27) or sublingual nitroglycerin (n = 36), or both (n = 14). Doppler measurements consisted of E (initial peak velocity), A (velocity at atrial contraction), deceleration time (time from E velocity to deceleration of flow extrapolated to baseline) and absolute A wave velocity (A' [peak A wave velocity minus velocity at onset of atrial contraction]).
Results: In patients with high pre-A wave pressure (> or 15 mm Hg), there was a greater change in the E/A' ratio during the Valsalva maneuver than in patients with a normal pre-A wave pressure (-1.22 +/- 1.1 vs. -0.35 +/- 0.17; p = 0.02). A similar change was seen when comparing the change in the E/A' ratio after administration of nitroglycerin in patients with a high versus a normal pre-A wave pressure (0.81 +/- 0.49 vs. 0.18 +/- 0.17; p < 0.001). These differences were present in patients with a normal E/A ratio at baseline.
Conclusions: Alterations in preload during assessment of Doppler echocardiographic indexes may be useful in noninvasively assessing left ventricular filling pressures.