Author + information
- Received March 9, 2001
- Revision received July 25, 2001
- Accepted August 20, 2001
- Published online December 1, 2001.
- Chen-Huan Chen, MDa,b,
- Barry Fetics, BEc,
- Erez Nevo, MD, DScc,
- Carlos E. Rochitte, MDc,
- Kuan-Rau Chiou, MDa,b,
- PhillipYu-An Ding, MD, PhDa,b,
- Miho Kawaguchi, MDc and
- David A. Kass, MDc,* ()
- ↵*Reprint requests and correspondence:
Dr. David A. Kass, Halsted 500, Division of Cardiology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287 USA.
Objectives The goal of this study was to develop and validate a method to estimate left ventricular end-systolic elastance (Ees) in humans from noninvasive single-beat parameters.
Background Left ventricular end-systolic elastance is a major determinant of cardiac systolic function and ventricular-arterial interaction. However, its use in heart failure assessment and management is limited by lack of a simple means to measure it noninvasively. This study presents a new noninvasive method and validates it against invasively measured Ees.
Methods Left ventricular end-systolic elastance was calculated by a modified single-beat method employing systolic (Ps) and diastolic (Pd) arm-cuff pressures, echo-Doppler stroke volume (SV), echo-derived ejection fraction (EF) and an estimated normalized ventricular elastance at arterial end-diastole (ENd): Ees(sb)= [Pd− (ENd(est)× Ps× 0.9)[/(ENd(est)× SV). The ENdwas estimated from a group-averaged value adjusted for individual contractile/loading effects; Ees(sb)estimates were compared with invasively measured values in 43 patients with varying cardiovascular disorders, with additional data recorded after inotropic stimulation (n = 18, dobutamine 5 to 10 μg/kg per min). Investigators performing noninvasive analysis were blinded to the invasive results.
Results Combined baseline and dobutamine-stimulated Eesranged 0.4 to 8.4 mm Hg/ml and was well predicted by Ees(sb)over the full range: Ees= 0.86 × Ees(sb)+ 0.40 (r = 0.91, SEE = 0.64, p < 0.00001, n = 72). Absolute change in Ees(sb)before and after dobutamine also correlated well with invasive measures: Ees(sb): ΔEes= 0.86 × ΔEes(sb)+ 0.67 (r = 0.88, p < 0.00001). Repeated measures of Ees(sb)over two months in a separate group of patients (n = 7) yielded a coefficient of variation of 20.3 ± 6%.
Conclusions The Eescan be reliably estimated from simple noninvasive measurements. This approach should broaden the clinical applicability of this useful parameter for assessing systolic function, therapeutic response and ventricular-arterial interaction.
☆ Supported by a grant from the National Institute on Aging (AG-12249) and intramural grants from the Veterans General Hospital-Taipei, Taiwan, R.O.C. (VGH 87-306, 88-304 and 89-257).
- Received March 9, 2001.
- Revision received July 25, 2001.
- Accepted August 20, 2001.
- American College of Cardiology