Abstract 9356: Diastolic Function Determines the Adrenergic Augmentation of Early Diastolic Intra-Ventriclular Pressure Gradient and Its Spatial Distribution
Introduction: Early diastolic left ventricular (LV) filling results from a progressive intra-ventricular pressure gradient (IVPG) extending from the left atrium to the LV apex.
Hypothesis: Adrenergic stimulation enhances the progressive IVPG in normal subjects but not in patients with diastolic dysfunction.
Methods: We studied 218 consecutive patients undergoing stress echocardiography who had no inducible ischemia, of which 29 were graded as normal diastolic function, 20 impaired relaxation (IR), 103 pseudo-normal filling (PN) and 66 restrictive filling (RF) according to the EAE/ASE recommendations. Color M mode Doppler (CMMD) images in the apical four chamber view were obtained at rest and during peak dobutamine infusion (20-40 mcg/kg/min). Total IVPG from the mitral annulus to LV apex, IVPG from the mitral annulus to mid LV (2 cm into the LV from the mitral annulus) and IVPG from mid LV to LV apex were calculated using the CMMD data to integrate the Euler equation.
Results: Mean age±SD was 60±12 years old. Male 51%. EF 59±8%. Total IVPG from the mitral annulus to LV apex was not different between groups at rest. The total IVPG increased more with dobutamine in normal subjects than in patients with diastolic dysfunction (Figure 1). The responses of IVPG from the mitral annulus to mid LV were not different among groups. The difference in the response of the total IVPG was due to the more marked augmentation of IVPG from mid LV to LV apex in normal subjects (Figure 2).
Conclusions: Diastolic dysfunction is associated with an inadequate adrenergic augmentation of the IVPG from mid LV to LV apex reflecting less apical suction.
- © 2011 by American Heart Association, Inc.