| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eur J Cardiothorac Surg 2006;29:S2-S3
© 2006 Elsevier Science NL
Editorial |
a Option on Bioengineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
b Department of Surgery, Division of Cardiothoracic Surgery, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, 62-258 CHS, Los Angeles, CA 90095-1741, USA
* Tel.: +1 310 206 1027; fax: +1 310 825 5895. (Email: gbuckberg{at}mednet.ucla.edu).
Keith [1], in 1918, provided an innovative and classic manuscript that stated, ‘we cannot claim to have mastered the mechanism of the human heart until we give a fundamental explanation of its architecture; an arrangement so complex that not any one of us succeeds in giving a satisfactory explanation.’ This underlying concept was the basis for a 2005 symposium held in Liverpool, England concerning ‘The New Concepts of Cardiac Anatomy,’ whereby a focal point of this meeting was a collaborative interaction amongst basic scientists and clinicians to determine if the helical ventricular myocardial band (HVMB), described in 1957 by Torrent-Guasp could fulfill the basic structural component that is responsible for cardiac function.
This supplemental volume of the European Journal of Cardiovascular Surgery will review the topics of this symposium, display differences of opinion about the validity of this HVMB concept and provide further insight from a broad spectrum of basic and clinical studies that examine if valid structure/function relationship exists. The underlying theme is that the scientific testing of viable action is the only solid proof of the soundness of the structural theory.
Complete understanding of cardiac architecture has perplexed anatomists for almost 500 years [2], yet an insight into the simplicity of heart formation was initiated in 1660 when Lower described an anatomic apical vortex in which a spiral configuration existed; internal cardiac fibers moved to the outside, while fibers on the outside moved to the inside. Borelli, in 1680, provided physiologic insight into the activity of underlying structure by mechanically defining ejection as squeezing blood from the ventricle, like ‘ wringing a towel.’ This motion is evident by the view of the working heart (see Videos 1 and 2 at http://ejcts.ctsnetjournals.org/content/vol27/issue2/images/data/202/DC1) and exists by twisting in systole to eject and reciprocally twisting to rapidly fill after emptying. This visual evidence is vastly different from the prevailing concept that the heart constricts to eject and dilates to fill. Such traditional concepts stem from the classic observations of Harvey [3], whose ingenious observations of the involvement of the pulmonary circulation in 1628 have properly established him as forefather of our current knowledge of the circulatory system.
The spiral configuration of the heart was conceptualized by many anatomists, but inability to unfold the structure to define the anatomic mechanisms responsible for cardiac formation has been described by Pettigrew in 1865 [4] as ‘Gordian knot of Anatomy,’ as his label for the complexity of configuration. Einstein, whose celebrated contributions of four papers that changed the scientific world were recently celebrated on their 100th anniversary in ‘Einstein 1905: the standard of greatness’ [5] focused upon simplicity. Perhaps elegance is simplicity, and confusion is complexity. Progress in knowledge is built upon growth, and this volume will evaluate if the work of Torrent-Guasp, who unwrapped the heart to uncover the ventricular myocardial fold, has provided us with the power of a simple muscular band that can explain the dual spiral configuration of helical heart that is responsible for subsequent function.
Torrent-Guasp's analysis of the components of the heart was achieved by hand dissection of the previously boiled heart. His observations describe a basal loop that wraps (like a buttress of a church) around a helix (like a church dome) comprising descending and ascending fiber pathways with a vortex at the apex (Fig. 1 ). The validity of these findings will create a revolution in understanding and may have profound implications for rethinking conventional concepts of normality and disease.
|
In the final analysis, form and function must fit for normality, and abnormal function thereby must follow abnormal form. This supplement will focus on enhancing the understanding of the normality of structure and demonstrate how distortion of form by disease may account for problems in pediatric and adult disease. Although astonishing progress has evolved in our capacity to image cardiac action in health and disease, such vision of integrated function currently addresses the intact whole heart rather than the underlying spatial configuration responsible for observed actions. Consequently, valid gross movement observations exist without an insight into specific geometric mechanisms responsible for normal and abnormal cardiac motions.
The components of this supplement will initially present the contributions of the participants in the Liverpool symposium. Unfortunately, Torrent-Guasp, whose lifetime work established the myocardial band, was not present because he passed away just prior to this symposium. Following a broad revisiting of Cardiac Architecture and the Fundamental Relation of Form and Function by two of my teachers, the initial presentation by Donald Ross shall address the legacy of Torrent-Guasp. The helical myocardial ventricular band impacts the theme of this symposium. The presentations at the meeting include studies of (1) anatomic architecture of the helical ventricular myocardial band, (2) an alternate view that disagrees with this HVMB concept and focuses upon the architectural cardiac syncytial mesh, (3) morphologic and functional studies of helical heart by non-invasive cardiac imaging, (4) conceptual electrophysiologic implications of HVMB, and (5) how implications of how the band influences congenital heart disease shall comprise the first part of the supplement.
The second component will survey several other elements described during the symposium and will also (6) include embryologic considerations of the ventricular band, (7) identify sonomicrometer definition of the function of basal and apical myocardial band components. For systolic ventricular filling (8) describe active diastolic suction by a muscular component, (9) demonstrate that intraventricular septum has a similar structure/function relationship as the left ventricular free wall, (10) describe the septum as a motor for the left and right ventricles, (11) identify diastolic dysfunction as a muscular action that can be changed pharmacologically, (12) demonstrate by MRI that the interaction between twisting motions for ejection and rapid filling may be related to sequential motions of the helical heart, (13) define motion measurements by MRI tissue phase mapping to provide an insight into ventricular fiber orientation, (14) integrate the MRI measurements of motion and fiber orientation with other imaging methods including echocardiography, sonomicrometer crystals, radionuclide ventriculography, and anatomic corrosion casts of spiral trabecular geometry in the left ventricle, (15) correlate radionuclide ventriculography motions (MUGA) with the HVMB, (16) define differences between cardiac motion and fiber shortening to distinguish whole heart movement and action of its parts, (17) present the hypothesis of an anisotropic conducting matrix with the electrical spiral of the heart, (18) correlate pacer asynchrony with dysfunction of the normal sequential actions of the myocardial band, (19) document the dysfunction of band dynamics introduced by biventricular pacing, and introduce a novel method of stimulating excitation–contraction pathways by high septal pacing, that relates to electrode positioning and the myocardial fold of the band, (20) employ the HVMB concept in surgical restoration of the dilated spherical heart with non-ischemic cardiomyopathy, by rebuilding an elliptical shape with the Pacopexy or septal anterior ventricular exclusion (SAVE) procedure, and (21) introduce the common theme of heart scaffold and human architectural structures by comparing Stonehenge and the heart. This Stonehenge component will follow the accompanying reports from the RESTORE team.
The aforementioned concert of electrical, imaging, structural, clinical, and architectural changes shall support novel thinking that demonstrates how structure/functional aspects of the HVMB can be used to understand normality. These observations may underscore the future development of underlying principles that may create guidelines that can be used to treat disease processes that upset normality. The innovative anatomic observations of Francisco Torrent-Guasp were the stimulus for this transformation of thinking about the cardiovascular system. His ideas were the torch for the novel discoveries that followed his vision and pathways, and this supplement is dedicated to his memory.
References
This article has been cited by other articles:
|
|
 |
|
  P. P. Sengupta, J. Korinek, M. Belohlavek, J. Narula, M. A. Vannan, A. Jahangir, and B. K. Khandheria Left Ventricular Structure and Function: Basic Science for Cardiac Imaging J. Am. Coll. Cardiol., November 21, 2006; 48(10): 1988 - 2001. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. H. Anderson and P. P. Lunkenheimer The helical heart. Eur. J. Cardiothorac. Surg., October 1, 2006; 30(4): 689 - 690. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
