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Myocardial torsion and cardiac fulcrum

J Trainini1, J Lowenstein2, M Beraudo3

  • 1Department of Cardiac Surgery, Hospital Presidente Perón, Buenos Aires, Argentina; Universidad Nacional de Avellaneda, Buenos Aires, Argentina.

Morphologie : Bulletin De L'Association Des Anatomistes
|July 11, 2020
PubMed

Insights

A newly discovered rigid structure, the fulcrum, underlies the right trigone in bovine and human hearts. This finding supports the spiral myocardial band theory, explaining cardiac torsion during systole and diastole.

Area of Science:

  • Cardiovascular Anatomy
  • Cardiac Physiology
  • Histology

Background:

  • The myocardial band's function in cardiac cycle mechanics has been debated.
  • Understanding its fixed points is crucial for explaining myocardial movements like torsion.

Purpose of the Study:

  • To investigate the anatomical and histological basis of the myocardial band's fixation points.
  • To identify structures that facilitate the helical rotation of the myocardial band during systole and diastole.

Main Methods:

  • Macroscopic and microscopic examination of seven young-bovine and seven human hearts (embryonic to adult).
  • Histological analysis focused on the region underlying the right trigone.

Main Results:

  • A novel structure, termed the fulcrum, was identified beneath the right trigone in all studied hearts.
  • The fulcrum exhibited varied histological compositions (osseous, chondroid, tendinous) depending on the specimen.
  • Myocardial attachment to this rigid fulcrum was consistently observed, with no myocardiocytes found at the trigones or valve bases.

Conclusions:

  • The identified fulcrum serves as the crucial fixation point for the spiral myocardial band.
  • This anatomical finding provides mechanical support for the helicoidal torsion model of myocardial function.
Abstract

Keywords:
Cardiac anatomyFulcrumHeartMyocardial torsionMyocardiumVentricular band

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