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JORGE C. TRAININI - JORGE LOWENSTEIN - MARIO BERAUDO - ALEJANDRO TRAININI - VICENTE MORA LLABATA - MARIO WERNICKE

The Authors

Jorge C. Trainini. Cardiac surgeon. Universidad Nacional de Avellaneda, Buenos Aires, Argentina. Universidad Católica de Murcia, España.

Jorge A. Lowenstein. Cardiologist, Ultrasound specialist. Investigaciones Médicas, Buenos Aires, Argentina.

Mario Beraudo. Cardiac surgeon. Clínica Güemes, Luján, Pcia de Buenos Aires, Argentina.

Alejandro Trainini. Cardiac surgeon. Hospital Presidente Perón, Buenos Aires, Argentina.

Vicente Mora Llabata. Cardiologist, Ultrasound specialist. Hospital “Dr Peset”, Valencia, España.

Mario Wernicke. Pathologist. Clínica Güemes, Luján, Pcia de Buenos Aires, Argentina.

MYOCARDIAL TORSION

Myocardial Torsion is a book different from others, simply because this book is unique, unusual, and I dare say with admiration, it is a curious book, partly magical, full of personality, for initiatory readers, revealing, provocative, challenging. The book has the infrequent peculiarity of being based, to a great extent, on original personal and multidisciplinary investigations, granting it an important extra value. The authors define their purpose since the first pages of the book: to provide solidity, validity and even more to Torrent Guasp’s concepts.

This is certainly a different book in its structure, content and elaboration. It is a text that the reader may admire or criticize, that may create skepticism or surprise at the new data it proposes, but which undoubtedly will leave nobody indifferent, and that is something few books can achieve.

Myocardial Torsion: Anatomo-Functional Research / Jorge C. Trainini ... [et al.]. - 1a ed.- Ciudad Autónoma de Buenos Aires: Biblos, 2020.

Libro digital, EPUB

Archivo Digital: descarga y online

Traducción de Amalia Pujadas ; Elena Lascano.

ISBN 978-987-691-797-1

1. Medicina. 2. Cardiología. I. Trainini, Jorge C. II. Pujadas, Amalia, trad. III. Lascano, Elena , trad.

CDD 616.12

The heart is a stately city of well-known boundaries with hidden, mysterious and unexplored pathways.

Working Hypothesis

The function of the heart corresponds to a mechanical dimension that should be addressed in terms of its structure, which is where we find the origin of the idea that led our research to explain its organic-functional integrity. If we stop in classical descriptions of the heart we realize that anatomical attention was focused on its external and internal surfaces, granting scant importance to the intimate muscle conformation. This was believed to be of a homogeneous solid nature with global uniform contraction, not considering that its mechanical capacity demanded a reinterpretation of its spatial anatomy and motions, leading us into other topics of its functioning that were completely disregarded by cardiology.

The anatomy of the heart was traditionally thought to be formed by spiraling muscle bundles, but these were never described in association with their physiology. Even though R. F. Shaner in 1923 expresses that the “myocardium is characterized by two flattened muscles shaped as a figure of 8. These muscles twist in opposite directions during systole, emptying its content”, it was the Spaniard Torrent Guasp who in 1970 initiated the description and interpretation of the myocardial muscle band, starting point to understand its motions. This was demonstrated in multiple dissections showing that the ventricular myocardium is made up of a group of muscle fibers coiled unto themselves, resembling a rope, flattened laterally as a band, which by giving two spiral twists describes a helix that limits the two ventricles and defines their performance.

An explanation for this muscle homogenization with an intricate anatomical arrangement that hides the myocardial band, implies considering that its structural solidity is required in birds and mammals so that blood is ejected at high speed in a limited time span by an organ that must serve two circulations (systemic and pulmonary). Currently, the myocardial band can be confirmed by the anatomical study of the heart via an adequate dissection, histological examination, magnetic resonance diffusion tensor imaging procedures, echocardiographic analysis and electrophysiological studies with three-dimensional electroanatomical mapping.

Despite all these considerations leading to discern the real internal myocardial anatomy, and contrary to the classical concept, dissection finds a structure with defined planes that allows successive and concatenated physiological motions of narrowing, shortening-twisting, lengthening-untwisting and expansion depending on the propagation of the electrical stimulus along its muscle pathways.

The anatomical evolutionary state of the heart agrees with ventricular mechanics but lacked the understanding of an electrical propagation that could accurately explain the physiology. The studies on this topic aim to show the integrity of an essential cardiac structure-function. The left ventricular endocardial and epicardial electrical activation performed in patients with three-dimensional electroanatomical mapping allowed considering this fundamental topic to analyze it. The circulatory duct of annelids works with a peristaltic mechanism in its contractile progression. The impulse along its length preserves a pattern of axial transmission, but after the cardiac duct twists in birds and mammals, radial transmission of the impulse is added, allowing the helical motion indispensable to produce the successive twisting-shortening motions during systole and untwisting-lengthening in the subsequent suction phase.

This pathway leading from structure to function induced the understanding of topics poorly explained by their mechanical organization, but which should be considered complementary among them and essential for the physiology of the heart.

The methods used in this study to explain the hypothesis of the anatomo-functional integrity of the heart were:

Findings and clinical data presented are the result of experimental tests performed under the approval of all the required regulatory authorities and under the informed consent of all patients following the principles described in the current World Medical Association Declaration of Helsinki (2013). The experiments were carried out according to the 1996 Law of scientific procedures in animals of the United Kingdom and the “National Institutes of Health” guide for the care and use of laboratory animals (NIH Publication No. 8023, updated in 1978).

Prologue

Probably only because of my age, I have had the fortune of making the leading prologue for a dozen books, generally of disciples and friends. It has always been an inspiring and personal pleasure rather than an obligation, a diversion in which one tries to give the future readers a global and necessary synoptic view of its virtues. I have to acknowledge that the work of making a prologue for the book of Professor Jorge Trainini et al.: Myocardial Torsion has been different from others, simply because this book is unique, unusual, and I dare say with admiration, it is a curious book, partly magical, full of personality, for initiatory readers, revealing, provocative, challenging, as a book about the knights of the Round Table presenting the reasons and pathways followed searching and perhaps finding the Holy Grail.

The book by Professor Jorge Trainini bonds with one of the most beautiful, romantic and for a long time misunderstood stories of the world of cardiology of the last hundred years: the life and work of Francisco Torrent Guasp (1931-2005), which would deserve in itself a film or better the production of a great opera, as was the life of the master, with its scientific zeals, its sufferings, its incomprehensible pathways, and an end that, unexpected and strangely striking, would be unbelievable in real life, as we would only see it as the exaggeration of the writer, passionate admirer of the hero.

Added to the attraction of a book with these characteristics is the unusual prose of professor Trainini, leader of this work. The book has the infrequent peculiarity of being based, to a great extent, on original personal and multidisciplinary investigations led by Professor Trainini, granting it an important extra value.

The text deals essentially with the anatomy and dynamic function of the heart clarified by the revolutionary anatomical studies of Torrent Guasp who, with his famous dissections, described how the ventricular myocardium was formed by muscle fibers which twisted unto themselves like a rope and flattened laterally as a band, shaped a helix that limited the two ventricular chambers defining their function. All his studies converged in the great outstanding and revolutionary contribution of diastolic suction as an active process due to the contraction of the myocardial band ascending segment.

The authors define their purpose since the first pages of the book: to provide solidity, validity and even more to the master’s concepts. The book attempts to answer a series of questions on cardiac physiology, which emerge when this is approached with the same anatomy of Torrent Guasp, and which are its essence: Do the bands surrounding the ventricles have a point of support similar to most muscles or are they supported by blood itself? How is ventricular torsion produced? Cardiac torsion implies friction mechanisms: is there an organic lubricating source? What is the relationship between ventricular vortex and myocardial torsion mechanisms? How is the mechanically active early diastolic ventricular suction explained? To answer these questions, among others, means fitting together many of the separate pieces that provide even greater strength to Torrents Guasp’s anatomy.

The book is originally organized into four chapters. In chapter 1 the authors write throughout nine sections, one of the most wonderful and original descriptions of myocardial functional anatomy that one could have possibly read. I wish to highlight, because I think it is especially interesting and surprisingly new, the concept of the cardiac fulcrum. The master Torrent Guasp considered that the cardiac band lacked a fixed point of support as the muscles in the musculoskeletal system, and which is the basis for their ability to develop force. The authors describe the structure of the origin and end of the myocardial band, which they call cardiac fulcrum in a parallelism and tribute to the concept of point of support to provide leverage expressed by Archimedes of Syracuse. It is amazing that in the first quarter of the 21st century they show us for the first time the existence of this structure with proper anatomical and histological entity, even more amazing in animal dissections. It is like finding an unknown island not represented in current maps. Only for this, one should be recreated and surprised in reading this book.

In chapter 2 the authors elegantly demonstrate, with 3D mapping electrophysiological studies of cardiac activation in human hearts, the propagation of the electrical stimulus in Torrent Guasp’s myocardial band, surpassing the theoretical ideas of the master.

In chapter 3, they express the theoretical and historical considerations of the cardiac suction pump, with a general vision obtained through the experimental models they developed to confirm the hypothesis.

Finally, in chapter 4 the book ends with a global synthesis of the complex cardiac functional mechanics dominated by the explanation of cardiac suction, the cornerstone of the master´s theory. This section stands out by the beautiful and difficult synthesis of cardiac torsion with myocardial strain echocardiographic techniques, for which the authors show exquisite proficiency.

Synthesis of Myocardial
Torsion Demonstration

The anatomo-physiological study we performed finds a starting point in the description of the myocardial band. Its spatial helical arrangement is in agreement with the mechanical function evidenced by the different segments that compose it.

The histological analysis sequence of the unfolded myocardial band demonstrates its linear orientation according to the segmental continuity of its spatial organization when the band is coiled, both in its internal and external surfaces. It can be seen that the myocardial structure is not a lattice but a band.

The myocardial band cannot be anatomically suspended and free in the thoracic cavity because it would be impossible to eject blood at a speed of 300 cm/s. Therefore, there must be a point of attachment, which was identified as the cardiac fulcrum (supporting point of leverage).

In this supporting point, the muscle fibers are inevitably forced to “intertwine” with the connective, chondroid or osseous fulcrum, and our anatomical and histological investigations have shown that this insertion attaches both the origin and end of the myocardial band.

This structural composition keeps correspondence with the activation of the myocardial band. The stimulus runs by its muscle pathways, but in order to fulfill the function proposed by its helical arrangement, it is essential for it to simultaneously activate the left ventricular descending and ascending segments. The transmission of the stimulus between them generates the necessary ventricular torsion (a situation similar to “wringing a towel”) that enables the ejection of the blood content in a limited time span with the necessary force to adequately supply the whole body.

The following suction phase of the heart is not feasible due to the small difference with peripheral pressure. Neither can it be passive. The untwisting of the heart in the first 100 ms of diastole (isovolumic diastolic phase) generates the negative intraventricular force to draw blood into the left ventricle, even in the absence of the right ventricle, as shown in experimental animals. This suction phase (“suction cup” mechanism) is active with energy expenditure, and implies that the heart cycle consists of three stages: systole, suction and diastole.

The opposing sliding motion of the left ventricular internal segments in relation to the external segments to achieve the mechanism of ventricular torsion, generates an inevitable friction between them. This would entail a high energy cost if the heart did not have a spongy system, with the participation of Thebesian and Langer venous conduits that act as a lubricating antifriction system.

The antifriction effect found in the histological studies of this spongy matrix and its conduits is due to the hyaluronic acid which flows across the myocardial thickness.

The helical arrangement of the band (structure) and ventricular torsion (function) turns the intraventricular blood content into a small eddy, explained by the physical laws of dissipative structures. This vortex, as a result of ventricular torsion, allows the blood to be ejected with the necessary force to supply the whole organism.

The investigation shows cardiac coherence from the myocardial band to the intraventricular vortex. This explains its high mechanical efficiency and also the procedures that were used in medical practice without a clear understanding of their mechanisms, as right ventricular removal, cardiomyoplasty, ventricular resynchronization and univentricular mechanical assistance surgeries. This consideration is of vital importance, as the assessment of torsion could be considered more reliable than functional class or ejection fraction and become an essential clinical predictor of heart failure.

CHAPTER 3
The Three-Stage Heart
The Suction Pump

1. Chronology of the suction mechanism concept

Erasistratus of Keos, a Greek anatomist and physician in Alexandria (300-250 BC), detailed the anatomy of the heart, described its valves, giving its current name to the tricuspid valve, and referred to the intermediate system between arteries and veins, which he called synanastomóseis as a first approach to the capillaries. The latter would have led Erasistratus, had he not been influenced by the pneumatic theory -according to which the pneuma should be transported by the arteries along the body to the veins by means of synanastomóseis –to a more precise knowledge of blood circulation.(114) Erasistratus considered that arteries did not carry blood, but pneuma, and assumed that the fundamental movement of the heart was dilatation produced by a contracting muscle.(108) This concept persisted in history by the work of Galen of Pergamus (130-200 AC). In 1542, Andrea Vesalius in his work De Humani Corporis fabrica established “when the left ventricle expands again, breath and blood are attracted once more towards the ventricle.”(114)

In 1628, William Harvey published the fundamental work of human physiology Exercitatio anatomica de motu cordis et sanguinis in animalibus. In it, he regarded systole as the main factor of cardiac function opposing Galen, who believed that the activity of the heart was manifested in its expansion, by means of the vis pulsifica.(114)

This concept remained unchanged despite the fact that the possibility of blood suction produced by the ventricles was repeatedly raised through different opinions.(29,108) Among them we can mention Zugenbühler (1815), Schubarth (1817), Wedemeyer (1828), Jonson (1823), and Chassignac (1836). There were also personalities such as Von den Velden (1906), Straub (1910) and Carl Wiggers (1928) who did not accept diastolic suction. Paradoxically, in Wiggers’ own laboratory, Louis Katz (1930) experimentally proved diastolic suction of the turtle’s left ventricle.(52,104,141)

It was necessary to wait until 1954 when Francisco Torrent Guasp (136) describes, within a theoretical framework, diastolic ventricular suction as an active contractile process, leading G Brecher (6) (1954) to assume that “achieving a demonstrative experimental evidence of diastolic ventricular suction is very difficult.” However, this same author elaborated on this concept and sometime later established the certain possibility of ventricular suction existence.(7, 8) The efforts, mainly of anatomical research, together with a deep reflective analysis on the subject, led to the acknowledgement of the ventricular myocardial band postulated by Torrent Guasp, (104) though without a clear physiological interpretation. This situation would progress in the physiological understanding of ventricular pressure in the different phases of the cardiac cycle through the work performed by F Torrent Guasp (106), D Streeter (98), P Lunkenheimer (61), G Buckberg (10-13) and J Trainini (137).

The experimental study in pigs by Juan Cosín Aguilar et al. in 2009, using piezoelectric crystals on the ventricular wall, considered the possibility of myocardial contraction in the isovolumic diastolic phase. (25) The study in humans conducted by Trainini et al. (122) in 2015 on the propagation of the electrical activity in the muscle band verifies cardiac suction as an interface between systole and diastole.

2. Active suction in the diastolic isovolumic phase

A fundamental issue we investigated, which did not have electrophysiological evidence, was to consider ventricular filling as an active phenomenon generated by a myocardial contraction that tends to lengthen the left ventricular apex-base distance after the ejective phase, thus producing a suction effect similar to a “suction cup”. This mechanism is explained by the persistence of the ascending segment contraction during the isovolumic diastolic phase.

We have found that the endocardium is completely depolarized during the first part of the QRS.(135) Buckberg also recorded that the mechanical contraction triggered by this electrical phenomenon begins about 50 ms after its onset and persists for approximately 350 ms. If according to our studies the depolarization of the ascending segment starts 25.8 ms on average after that of the descending segment and its contraction persists for the same period of time, the condition of ventricular contraction will last approximately 400 ms. On the other hand, as ventricular systole lasts about 300 ms, the remaining 100 ms correspond to the diastolic isovolumic phase (erroneously called isovolumic relaxation, because as we see there is ventricular contraction). Briefly, during the initial part of this phase the ascending segment remains contracted as a result of the depolarization that occurred during the QRS. To explain this late contraction, depolarizations after the QRS are therefore, not required, as Pedro Zarco assumed.(143,144)

The final part of the QRS corresponds in our investigation to the activation of the ascending segment (chapter 2, Figure 2.5). In this way, during the diastolic isovolumic phase, the contraction necessary to generate suction (“suction cup effect”) occurs. With the onset of untwisting during the diastolic isovolumic phase the ascending segment progressively lengthens, generating negative intraventricular pressure with this segment still contracted (active process) as an energy residue of the twisting process. On this point Zarco expressed in 2001 “there is a point in which we cannot agree: that the straightening of the ascending segment is due to an active contraction of the heart muscle in full diastole.” (143) It is precisely this situation what we have found in our investigation constituting the mechanism that achieves fast ventricular filling in a short period of time during diastole, estimated as 20% of its duration.(121-127)