Author + information
- Received January 29, 2014
- Revision received April 18, 2014
- Accepted April 30, 2014
- Published online November 11, 2014.
- Richard Ro, MD∗,
- Dan Halpern, MD∗,
- David J. Sahn, MD†,
- Peter Homel, PhD∗,
- Milla Arabadjian, NP∗,
- Charles Lopresto, BA∗ and
- Mark V. Sherrid, MD∗∗ ()
- ∗Division of Cardiology, Mount Sinai Roosevelt and St. Luke's Hospitals, Icahn School of Medicine at Mount Sinai, New York, New York
- †Division of Pediatric Cardiology, Oregon Health and Science University, Portland, Oregon
- ↵∗Reprint requests and correspondence:
Dr. Mark V. Sherrid, Division of Cardiology, Mount Sinai Roosevelt Hospital, 1000 10th Avenue, 3B-30, New York, New York 10019.
Background The hydrodynamic cause of systolic anterior motion of the mitral valve (SAM) is unresolved.
Objectives This study hypothesized that echocardiographic vector flow mapping, a new echocardiographic technique, would provide insights into the cause of early SAM in obstructive hypertrophic cardiomyopathy (HCM).
Methods We analyzed the spatial relationship of left ventricular (LV) flow and the mitral valve leaflets (MVL) on 3-chamber vector flow mapping frames, and performed mitral valve measurements on 2-dimensional frames in patients with obstructive and nonobstructive HCM and in normal patients.
Results We compared 82 patients (22 obstructive HCM, 23 nonobstructive HCM, and 37 normal) by measuring 164 LV pre- and post-SAM velocity vector flow maps, 82 maximum isovolumic vortices, and 328 2-dimensional frames. We observed color flow and velocity vector flow posterior to the MVL impacting them in the early systolic frames of 95% of obstructive HCM, 22% of nonobstructive HCM, and 11% of normal patients (p < 0.001). In both pre- and post-SAM frames, we measured a high angle of attack >60° of local vector flow onto the posterior surface of the leaflets whether the flow was ejection (59%) or the early systolic isovolumic vortex (41%). Ricochet of vector flow, rebounding off the leaflet into the cul-de-sac, was noted in 82% of the obstructed HCM, 9% of nonobstructive HCM, and none (0%) of the control patients (p < 0.001). Flow velocities in the LV outflow tract on the pre-SAM frame 1 and 2 mm from the tip of the anterior leaflet were low: 39 and 43 cm/s, respectively.
Conclusions Early systolic flow impacts the posterior surfaces of protruding MVL initiating SAM in obstructive HCM.
- hypertrophic cardiomyopathy
- hypertrophic obstructive cardiomyopathy
- LVOT obstruction
- vector flow map
Hitachi-Aloka, Ltd., provided the echocardiography machine used in this research. The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Steven Nissen, MD, served as the Guest Editor for this paper.
- Received January 29, 2014.
- Revision received April 18, 2014.
- Accepted April 30, 2014.
- American College of Cardiology Foundation