Mechanistic insights into posterior mitral leaflet inter-scallop malcoaptation during acute ischemic mitral regurgitation

David T. Lai, Frederick A. Tibayan, Truls Myrmel, Tomasz A. Timek, Paul Dagum, George T. Daughters, David Liang, Neil B. Ingels, D. Craig Miller

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Background - Three-dimensional dynamics of the 3 individual scallops within the posterior mitral leaflet during acute ischemic mitral regurgitations have not been previously measured. Methods - Radiopaque markers were sutured to the mitral annulus, papillary muscle tips, and leaflet edges in 13 sheep. Immediately postoperatively, under open-chest conditions, 3-D marker coordinates were obtained using high-speed biplane videofluoroscopy before and during echocardiographically verified acute ischemic mitral regurgitation produced by occlusion of the left circumflex coronary artery. Results - During acute ischemic mitral regurgitation, at end systole, the anterolateral edge of the central scallop was displaced 0.8±0.9 mm laterally and 0.9±0.6 mm apically away from the anterolateral scallop; such displacement correlated with lateral displacement of the lateral annulus (R2=0.7, SEE=0.7 mm, P<0.001) and movement of the right lateral annulus away from the nonischemic anterior papillary tip (R2=0.6, SEE=0.8 mm, P=0.002), respectively. End-systolic displacement of the posteromedial edge of the central scallop was 1.4±0.9 mm anteriorly and 0.9±0.6 mm laterally away from the posteromedial scallop, corresponding to anterior displacement of the mid-lateral annulus (R2=0.5, SEE=1.0 mm, P<0.001). Conclusions - Malcoaptation of the scallops within the posterior leaflet during acute left ventricular ischemia is a novel observation. The primary geometric mechanism underlying scallop malcoaptation in acute ischemic mitral regurgitation was annular dilatation, which hindered leaflet coaptation by drawing the individual scallops apart. These findings support the use of annular reduction in the repair of ischemic mitral regurgitation and also suture closure of prominent subcommissures between posterior leaflet scallops.

Original languageEnglish (US)
Pages (from-to)I40-I45
JournalCirculation
Volume106
Issue number13 SUPPL.
StatePublished - Sep 24 2002
Externally publishedYes

Keywords

  • Coronary artery disease
  • Ischemic heart disease
  • Ischemic mitral regurgitation
  • Leaflet dynamics
  • Mitral scallops
  • Mitral valve 3-D geometry
  • Posterior mitral leaflet

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Fingerprint

Dive into the research topics of 'Mechanistic insights into posterior mitral leaflet inter-scallop malcoaptation during acute ischemic mitral regurgitation'. Together they form a unique fingerprint.

Cite this