Richard Ro1, Dan Halpern1, David J Sahn2, Peter Homel1, Milla Arabadjian1, Charles Lopresto1, Mark V Sherrid3. 1. Division of Cardiology, Mount Sinai Roosevelt and St. Luke's Hospitals, Icahn School of Medicine at Mount Sinai, New York, New York. 2. Division of Pediatric Cardiology, Oregon Health and Science University, Portland, Oregon. 3. Division of Cardiology, Mount Sinai Roosevelt and St. Luke's Hospitals, Icahn School of Medicine at Mount Sinai, New York, New York. Electronic address: msherrid@chpnet.org.
Abstract
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.
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.
Authors: Robert A Levine; Albert A Hagége; Daniel P Judge; Muralidhar Padala; Jacob P Dal-Bianco; Elena Aikawa; Jonathan Beaudoin; Joyce Bischoff; Nabila Bouatia-Naji; Patrick Bruneval; Jonathan T Butcher; Alain Carpentier; Miguel Chaput; Adrian H Chester; Catherine Clusel; Francesca N Delling; Harry C Dietz; Christian Dina; Ronen Durst; Leticia Fernandez-Friera; Mark D Handschumacher; Morten O Jensen; Xavier P Jeunemaitre; Hervé Le Marec; Thierry Le Tourneau; Roger R Markwald; Jean Mérot; Emmanuel Messas; David P Milan; Tui Neri; Russell A Norris; David Peal; Maelle Perrocheau; Vincent Probst; Michael Pucéat; Nadia Rosenthal; Jorge Solis; Jean-Jacques Schott; Ehud Schwammenthal; Susan A Slaugenhaupt; Jae-Kwan Song; Magdi H Yacoub Journal: Nat Rev Cardiol Date: 2015-10-20 Impact factor: 32.419
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