TY - JOUR
T1 - Cutting second-order chords does not prevent acute ischemic mitral regurgitation
AU - Rodriguez, Filiberto
AU - Langer, Frank
AU - Harrington, Katherine B.
AU - Tibayan, Frederick A.
AU - Zasio, Mary K.
AU - Liang, David
AU - Daughters, George T.
AU - Ingels, Neil B.
AU - Miller, D. Craig
PY - 2004/9/14
Y1 - 2004/9/14
N2 - Background-Cutting anterior mitral leaflet second-order chordae has been proposed for repair in ischemic mitral regurgitation (IMR). We examined the efficacy of such chordal cutting in preventing acute IMR. Methods and Results-Six sheep underwent radiopaque marker placement (left ventricle, mitral annulus, papillary muscles [PMs], and leaflets). The largest second-order chord from each PM was encircled with exteriorized wire snares. Three-dimensional marker coordinates were obtained with biplane videofluoroscopy before and during acute ischemia (80 seconds of mid-circumflex occlusion). Color Doppler transesophageal echocardiography was used to grade MR on a 0 to 4+ scale. Data were acquired immediately before and after dividing second-order chordae. Slope of the end-diastolic volume-stroke work relationship (PRSW) was calculated to assess systolic function. Chordal cutting increased anterior leaflet inflection angle (155±12 versus 162±9 degrees; P=0.03), resulting in a flatter leaflet, but did not increase effective leaflet length (1.97±0.24 versus 2.08±0.23 cm; P=0.15); PRSW decreased (63±15 versus 56±12 mm Hg; P=0.008). Both before and after chordal cutting, ischemia caused: Septal-lateral annular dilation (P=0.005), posterior PM displacement away from the mid-septal annulus (P=0.06), increased leaflet tenting area (P=0.001), and increased leaflet tenting volume (P=0.002). Before chordal cutting, MR increased significantly during ischemia (0.5±0.3 versus 1.7±0.4; P<0.001), and IMR increased similarly even after the second-order chords were cut (0.7±0.4 versus 1.9±0.9; P<0.001). Conclusions-Cutting second-order chordae resulted in LV systolic dysfunction and neither prevented nor decreased the severity of acute IMR, septal-lateral annular dilation, leaflet tenting area, or leaflet tenting volume.
AB - Background-Cutting anterior mitral leaflet second-order chordae has been proposed for repair in ischemic mitral regurgitation (IMR). We examined the efficacy of such chordal cutting in preventing acute IMR. Methods and Results-Six sheep underwent radiopaque marker placement (left ventricle, mitral annulus, papillary muscles [PMs], and leaflets). The largest second-order chord from each PM was encircled with exteriorized wire snares. Three-dimensional marker coordinates were obtained with biplane videofluoroscopy before and during acute ischemia (80 seconds of mid-circumflex occlusion). Color Doppler transesophageal echocardiography was used to grade MR on a 0 to 4+ scale. Data were acquired immediately before and after dividing second-order chordae. Slope of the end-diastolic volume-stroke work relationship (PRSW) was calculated to assess systolic function. Chordal cutting increased anterior leaflet inflection angle (155±12 versus 162±9 degrees; P=0.03), resulting in a flatter leaflet, but did not increase effective leaflet length (1.97±0.24 versus 2.08±0.23 cm; P=0.15); PRSW decreased (63±15 versus 56±12 mm Hg; P=0.008). Both before and after chordal cutting, ischemia caused: Septal-lateral annular dilation (P=0.005), posterior PM displacement away from the mid-septal annulus (P=0.06), increased leaflet tenting area (P=0.001), and increased leaflet tenting volume (P=0.002). Before chordal cutting, MR increased significantly during ischemia (0.5±0.3 versus 1.7±0.4; P<0.001), and IMR increased similarly even after the second-order chords were cut (0.7±0.4 versus 1.9±0.9; P<0.001). Conclusions-Cutting second-order chordae resulted in LV systolic dysfunction and neither prevented nor decreased the severity of acute IMR, septal-lateral annular dilation, leaflet tenting area, or leaflet tenting volume.
KW - Contractility
KW - Ischemia
KW - Mitral valve
KW - Regurgitation
KW - Remodeling
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U2 - 10.1161/01.CIR.0000138396.24335.6a
DO - 10.1161/01.CIR.0000138396.24335.6a
M3 - Article
C2 - 15364845
AN - SCOPUS:4644360062
SN - 0009-7322
VL - 110
SP - II91-II97
JO - Circulation
JF - Circulation
IS - 11 SUPPL.
ER -