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contribution provided by each segment in which the myocardium is divided, according to the single muscle band model (unpublished data), finding that on average the RS contributes 25%, the LS 12%, the DS 37%, and the AS 26%.In this way, the BL contributes approximately 37% and the AL 63%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.