Experimental study of the so called left ventricular isovolumic relaxation phase.

Introduction And Objectives: Left ventricular filling begins in the ventricular isovolumic relaxation phase. According to the Torrent-Guasp myocardial band theory, this phase results from the contraction of the final portion of the myocardial band: the ascending segment of the apical loop. The objectives were to study the myocardial mechanisms influencing transmitral flow during early diastole and to determine whether the rapid ventricular filling phase involves contraction or relaxation.

The helical ventricular myocardial band of Torrent-Guasp: potential implications in congenital heart defects.

The new concepts of cardiac anatomy and physiology, based on the observations made by Francisco Torrent-Guasp's discovery of the helical ventricular myocardial band, can be useful in the context of the surgical strategies currently used to manage patients with congenital heart defects. The potential impact of the Torrent-Guasp's Heart on congenital heart defects have been analyzed in the following settings: ventriculo-arterial discordance (transposition of the great arteries), double (atrio-ventricular and ventriculo-arterial) discordance (congenitally corrected transposition of the great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and complex intra-ventricular malformations. The functional interaction of right and left ventricles occurs not only through their arrangements in series but also thanks to the structural spiral features.

The sequence of regional ventricular motion.

Objective: The chronology of electrical events that mechanically activate the myocardium has been described as initiating at the level of the septum, spreading to the apex, then to the bodies of both ventricles and eventually to the base of the heart (apex-to base activation). It has recently been suggested that the myocardium is a single muscular band that conforms a double-loop helicoid. Contraction of the myocardium would follow the trajectory of the muscular fibers that originate at the pulmonary artery towards the body of the left ventricle and to the aorta (base-to apex contraction).

The helical ventricular myocardial band: global, three-dimensional, functional architecture of the ventricular myocardium.

We are currently witnessing the advent of new diagnostic tools and therapies for heart diseases, but, without serious scientific consensus on fundamental questions about normal and diseased heart structure and function. During the last decade, three successive, international, multidisciplinary symposia were organized in order to setup fundamental research principles, which would allow us to make a significant step forward in understanding heart structure and function. Helical ventricular myocardial band of Torrent-Guasp is the revolutionary new concept in understanding global, three-dimensional, functional architecture of the ventricular myocardium.

Towards new understanding of the heart structure and function.

Structure and function in any organ are inseparable categories, both in health and disease. Whether we are ready to accept, or not, many questions in cardiovascular medicine are still pending, due to our insufficient insight in the basic science. Even so, any new concept encounters difficulties, mainly arising from our inert attitude, which may result either in unjustified acceptance or denial.

Systolic ventricular filling.

The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities.

The structure and function of the helical heart and its buttress wrapping. VII. Critical importance of septum for right ventricular function.

The macroscopic structure of the right ventricle includes a transverse basal loop for the free wall, and oblique septal components, originating from the descending and ascending segments of the apical loop. Data is presented that determines why right ventricular function is related principally to intraventricular septal function, and why right ventricular failure is magnified by septal stunning caused by poor myocardial protection. The background of this architectural/functional change can explain normal right ventricular function, the relationship of right ventricular performance to pulmonary vascular resistance, experimental studies that characterize right ventricular performance after architectural free wall ablation, right ventricular disconnection, right coronary occlusion, and free wall replacement.

The structure and function of the helical heart and its buttress wrapping. VI. Geometric concepts of heart failure and use for structural correction.

The macroscopic basis for congestive heart failure is defined as conversion of a helical heart, whereby the apical loop fiber angle orientation that produces a 60% ejection fraction becomes more transverse to develop a spheric configuration. The geometric consequence is flattening of the apical loop architecture, so that the 15% shortening can produce only 30% ejection fraction. The fundamental shape change is alteration of normal relationships between the transverse basal loop and oblique apical loop, to make the apical loop become more basal through more transverse fiber orientation.

The structure and function of the helical heart and its buttress wrapping. V. Anatomic and physiologic considerations in the healthy and failing heart.

A macroscopic structure of an elliptic heart, formed by the helix provided by the apical loop, is defined and related, initially, to normal function. To define the sequence of normal progressive muscular activity, cardiac pressure, magnetic resonance imaging (MRI), and multiple gated acquisition (MUGA) records are reviewed. This novel format of structure for the helical heart is then compared with historic studies of ventricular structure.

The structure and function of the helical heart and its buttress wrapping. IV. Concepts of dynamic function from the normal macroscopic helical structure.

Torrent-Guasp's model of the helical heart is presented, which includes the cardiac muscular structures that produce 2 simple loops and that start at the pulmonary artery and end in the aorta. These components include a horizontal basal loop that surrounds the right and left ventricles, changes direction through a spiral fold in the ventricular band to cause a ventricular helix produced by now obliquely oriented fibers, forming a descending and ascending segment of the apical loop with an apical vortex. These anatomic concepts are successively activated to produce a sequence of narrowing by the basal loop, shortening by the descending segment, lengthening by the ascending segment, and widening in the cardiac cycle that causes ventricular ejection to empty and suction to fill.

The structure and function of the helical heart and its buttress wrapping. I. The normal macroscopic structure of the heart.

The Gordian knot of anatomy has been the architectural arrangement of ventricular muscle mass, which may have finally become understood. The description of Francisco Torrent-Guasp's model of the helical heart is presented, which includes the cardiac structures that produce 2 simple loops that start at the pulmonary artery and end in the aorta. An unscrolled ventricular band is shown, achieved by blunt dissection that extends between the points of origin of the right ventricle, at the pulmonary artery root, to termination at the aortic root, in the left ventricle.

[Agonist-antagonist mechanics of the descendent and ascendent segments of the ventricular myocardial band].

In this article the macroscopic structure of the ventricular myocardium is described, which is configurated as a band along which four segments can be distinguished. Such band traces a helicoids with two spiral turns in the space, in its trajectory from the pulmonary artery root to the aortic root, delimits both ventricular cavities. Our interest in achieving the knowledge of the coherent relationship between that anatomical fact and cardiac mechanics, which necessarily exist between the form and the function of any organ, has led us to perform some experimental approaches which show that the volume decrease of the ventricular cavities takes place, simultaneously with the descent of the base, thanks to the agonist contraction of the descending segment of the band, previously stretched out in a rectilinear way.

[A containing prosthesis in the treatment of dilated myocardiopathy].

A contention prosthesis is proposed for the surgical treatment of the dilated cardiomyopathy. The device of this prosthesis is based on experimental anatomical, physiological and dynamic data through which new concepts of the ventricular myocardium structure and function have been obtained.

[4 proposals for ventricular remodelling in the surgical treatment of dilated myocardiopathy].

Four surgical procedures are proposed to achieve an efficient remodelling of the ventricles with a low injury to heart muscle, for the treatment of the dilated cardiomyopathy. Those procedures are based the partial ventriculectomy technique of Batista an on the new conception of the macroscopical myocardium structure of the ventricles evidenced in the second half of the present century.

The anisotropic structure of the human left and right ventricles.

An important determinant of cardiac output derives from the structure of the ventricular wall given by the arrangement of the cardiac muscle fibres. A key feature of this arrangement is both a global and local anisotropy. First, a preparation method necessary for analyzing the main aspects of spatial fibre architecture is outlined.

A silicone rubber mould of the heart.

The macroscopical structure of the ventricular myocardium has been an unsolved problem since the XVIth century, when Anatomy started as an authentic science. Since then the spatial organization of the myocardial fibres has represented, as Pettigrew says, "an arrangement so unusual and perplexing, that it has long been considered as forming a kind of Gordian knot in Anatomy. Of the complexity of the arrangement I need not speak further than to say that Vesalius, Albinus, Haller and De Blainville, all confessed their-inability to unravel it".

[Elastic].

Since the ventricular myocardium is made up of a band of myocardial fibres which are configured into a complicated three-dimensional helical way, some time spent handling and observing this teaching model can help any cardiologist involved in imaging methods to understand and interpret the structural basis of the motion patterns of the heart. We concede that we need the cooperation of all disciplines to elucidate functional understanding of the myocardial band structure described above.

The difficult access to morphology of the heart: clinical implications.

The literature on the morphology of the heart is reviewed within the context of recent histological findings. There is strong evidence for a dualistic myocardial function, whereby both ventricular constricting and expanding forces are supposed to act synchronously although with variable effect over the heart cycle.The morphological basis of this dualistic myocardial function is the contorted rope-like structure worn into the bulk of the heart muscle.