Author + information
- Received July 23, 2010
- Revision received September 17, 2010
- Accepted September 21, 2010
- Published online January 1, 2011.
- Kelley C. Stewart, MS⁎,
- Rahul Kumar, MD†,
- John J. Charonko, PhD⁎,
- Takahiro Ohara, MD, PhD†,
- Pavlos P. Vlachos, PhD⁎ and
- William C. Little, MD†,⁎ ()
- ↵⁎Reprint requests and correspondence
: Dr. William C. Little, Cardiology Section, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1045
Objectives This study evaluated early diastolic filling dynamics using a semiautomated objective analysis of filling velocities obtained from color M-mode echocardiography.
Background Diastolic function can be evaluated from color M-mode echocardiography by measuring the early diastolic flow propagation velocity (Vp) from the slope of a single linear approximation of an isovelocity contour. However, this method has limitations and may not accurately represent diastolic filling.
Methods We used a semiautomated objective analysis of color M-mode echocardiograms from a development cohort of 125 patients with varying diastolic function to quantify left ventricular filling velocities. Early diastolic filling was not accurately described with a single propagation velocity; instead, the rapid initial filling velocity abruptly decelerated to a slower terminal velocity. Then, we evaluated a new measure of diastolic function in a separate group of 160 patients.
Results Compared with normal filling, diastolic dysfunction with restricted filling had a lower initial velocity (53 ± 21 cm/s vs. 87 ± 29 cm/s, p < 0.001), and the deceleration point occurred closer to the mitral annulus (2.4 ± 0.6 cm vs. 3.1 ± 0.7 cm, p < 0.05). The product of the initial velocity and the distance to the deceleration point from the mitral annulus, indicating the strength of the early filling (Vs), was progressively reduced with diastolic dysfunction. In a separate validation cohort of 160 patients, Vs better recognized diastolic dysfunction (classified by reduced diastolic intraventricular pressure gradient, elevated pulmonary capillary wedge pressure, or elevated B-type natriuretic peptide) than Vp did.
Conclusions Early diastolic flow propagation occurs with an initial rapid velocity that abruptly decelerates to a terminal velocity. With diastolic dysfunction, the initial velocity is slower and the deceleration point occurs closer to the mitral annulus than with normal filling. A new parameter that combines these 2 effects (Vs) provides a more accurate assessment of diastolic function than the conventional propagation velocity.
This work is partially supported by a National Science Foundation Graduate Research Fellowship Grant (0547434). 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 Science Foundation. Financial support has also been received from Wake Forest Translational Science Institute. An application for a provisional patent covering the analysis program has been filed by Virginia Tech and Wake Forest Universities, which employ the authors. The authors have reported that they have no relationships to disclose.
- Received July 23, 2010.
- Revision received September 17, 2010.
- Accepted September 21, 2010.
- American College of Cardiology Foundation