Myocardial Dissection and Percentage Segmental
Contribution of Ventricular Mass.
The standardization and protocolization of its procedure have been
widely reported previously by various authors3,7.
However, questions cited by a current of thought that is parallel and
discordant to the single muscle model of the myocardium are taken up
again11. The ”predominance
principle”12 was discussed as one where muscle fibers
reveal their unique functional anatomic vector planes, rather than
specific eclectic ones within the ventricular mass, demonstrating that
myocardial fiber fields follow a consistent and comparable
organizational pattern. within normal four-chamber mammalian hearts.
Cardiac muscle is also embedded in a specific connective tissue
scaffold, so the term ”myocardial fiber” refers to cardiac myocytes
surrounded and interconnected by a perimysium, this being the
scaffolding for the hierarchy of myocardial fibers, and the predominant
local direction of its longitudinal axes defines the macroscopic
architecture becoming evident on blunt dissection. In Editorial
Letter11 it is argued that Professor Streeter refers
to the following as ”the wall of the heart” with a
three-dimensional continuum formed basically by the one-dimensional
cylindrical element, the cardiac muscle cell” 13.
However, in another article, given the reproducibility of the dissection
technique, he comments as follows ”all myocardial dissection is an
artifact but said artifact is reproducible and significant when the main
pathway of the fiber is the only arbiter of the dissection
protocol” 14, Torrent-Guasp never questioned the
existence and importance of structural and functional interconnections
at different length scales, allowing the myocardium to be considered as
a ”functional syncytium”, identifying pattern driving its behavior,
respecting the predominance and fiber direction.
Antúnez-Montes and Sosa-Olavarría quantified the mass contribution
provided by each segment in which the myocardium is divided, according
to the single muscle band model (unpublished data), finding that on
average the RS contributes 25%, the LS 12%, the DS 37%, and the AS
26%.In this way, the BL contributes approximately 37% and the AL 63%
to the ventricular economy. (Table 1) This does not
differ from what was recently reported by Trainini, analyzing the
contribution of different segments of the helicoidal heart in the free
walls of the right and left ventricle and the septum, they have reported
histologically a wide area of osteochondroid tissue in a vicinity of
the right fibrous trigone which they have decided to call (cardiac
fulcrum), something that Torrent-Guasp had attributed to the residual
volume of blood calling this fulcrum as (Hemoskeleton), supposed to
facilitate the ventricular torsion movements15, 16,
17. The osteochondroid structure had already been identified as similar
to ”bone tissue” attributing it to the nature of the fibrous trigone by
Antúnez-Montes in 2014, with comments in a video class found on the
virtual platform https://www.youtube.com/watch?v= HZmaPA837Q8&t=727s at
10:22.