Author + information
- Received May 8, 2012
- Accepted May 21, 2012
- Published online September 1, 2012.
- Takahiro Ohara, MD, PhD⁎,
- Cassie L. Niebel, BS†,
- Kelley C. Stewart, PhD†,
- John J. Charonko, PhD†,
- Min Pu, MD, PhD⁎,
- Pavlos P. Vlachos, PhD† and
- William C. Little, MD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. William C. Little, Section on Cardiology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1045
Objectives The aim of this study was to evaluate the hypothesis that the adrenergic response of the intraventricular pressure difference (IVPD) is reduced in patients with preserved ejection fraction (EF) and diastolic dysfunction (DD).
Background In early diastole, there is a progressive IVPD extending from the left atrium (LA) to the left ventricular (LV) apex. In response to adrenergic stimulation, as occurs during exercise, the IVPD increases allowing rapid filling without an abnormal increase in LA pressure. Patients with heart failure with a reduced EF have impaired adrenergic augmentation of the IVPD.
Methods We studied 166 consecutive patients undergoing dobutamine stress echocardiography who had no inducible ischemia and an EF ≥50%, of which 21 had normal diastolic function, 14 had impaired relaxation (grade 1), 80 had pseudonormal filling (grade 2), and 51 had restrictive filling (grade 3). Color M-mode Doppler (CMMD) images of mitral inflow were obtained at rest and during low (10 μg/kg/min) and peak (20 to 40 μg/kg/min) doses of dobutamine. The total IVPD from the LA to LV apex, LA to mid-LV, and mid-LV to the LV apex were calculated using the CMMD data to integrate the Euler equation.
Results Total IVPD was not different between groups at rest. With dobutamine, the total IVPD increased by 2.20 ± 1.95 mm Hg in normal subjects and by only 0.73 ± 1.33 mm Hg, 1.84 ± 1.63 mm Hg, and 1.08 ± 1.57 mm Hg in patients with grades 1, 2, and 3 DD, respectively. This difference was due to a failure in augmentation of IVPD from the mid-LV to the LV apex, indicating reduced apical ventricular suction with DD, whereas the IVPD from the LA to the mid-LV responded similarly to dobutamine in normal subjects and those with DD.
Conclusions In patients with preserved EF, DD is associated with a reduced adrenergic augmentation of the IVPD from the mid-LV to the LV apex, reflecting less apical suction.
- color M-mode Doppler
- diastolic dysfunction
- dobutamine stress echocardiography
- intraventricular pressure difference
This work was partially supported by a National Institutes of Health R21 Grant (HL106276-01A1) and a National Science Foundation Graduate Research Fellowship Grant (0547434). The Wake Forest Translational Science Institute also provided financial support. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Institutes of Health or National Science Foundation. Dr. Little has relationships with CorAssist Cardiovascular, Ltd., Boston Scientific, Medtronic, Inc., Bio-Control Medical, CVRx, Inc., Amylin Pharmaceuticals, Gilead Sciences, Inc., and Ono Pharma USA, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received May 8, 2012.
- Accepted May 21, 2012.
- American College of Cardiology Foundation