Blood flow structure and dynamics, and ejection mechanism in the left ventricle: Analysis using echo-dynamography

Motonao Tanaka, Tsuguya Sakamoto, Shigeo Sugawara, Hiroyuki Nakajima, Yoshiaki Katahira, Shigeo Ohtsuki, Hiroshi Kanai

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)

Abstract

Using our "echo-dynamography", blood flow structure and flow dynamics during ventricular systole were investigated in 10 normal volunteers. The velocity vector distribution demonstrated blood flow during ejection was laminar along the ventricular septum. The characteristic flow structure was observed in each cardiac phases, early, mid- and late systole and was generated depending on the wall dynamic events such as peristaltic squeezing, hinge-like movement of the mitral ring plane, bellows action of the ventricle and dimensional changes in the funnel shape of the basal part of the ventricle, which were disclosed macroscopically by using the new technology of high speed scanning echo-tomography and microscopically by the strain rate distribution measured by phase tracking method. The pump function was reflected on the changes in the flow structure represented by the flow axis line distribution and the acceleration along the flow axis line. The acceleration of the ejection had three modes, "A", "B" and "C", and generated by the wall dynamic events. "A" appeared from the apical to the outflow area along the main flow axis line, "B" along the anterior mitral leaflet and the branched flow axis line, and "C" generated by the high speed vortex behind the mitral valve. The magnitude of the acceleration was estimated quantitatively from the velocity gradient along the flow axis line. Macroscopic and microscopic asynchrony in the myocardial contraction and extension appeared systematically in the local part of the ventricular wall, which was helpful for making the flow structure and for performing the smooth pump function.

Original languageEnglish
Pages (from-to)86-101
Number of pages16
JournalJournal of cardiology
Volume52
Issue number2
DOIs
Publication statusPublished - 2008 Oct

Keywords

  • Blood flow dynamics
  • Echo-dynamography
  • Ejection mechanism
  • Flow axis line
  • Flow velocity vector
  • Velocity gradient
  • Ventricular wall dynamics

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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