The present research is the last step of a research activity started in 2011 and carried out successfully by the same Sapienza's Research Group (SRG) under Sapienza¿s support (see https://sites.google.com/a/uniroma1.it/paolanardinocchi/attivita for an overview of our ongoing activity). In our mind, this project is the natural conclusion of a 10 years long collaboration between medical doctors and engineers. We aim to use all our skills and competences to build a morphometric atlas of the left heart, based on the data we acquired in the past years and on the mechanical models we built on those data.
Specifically, the aim of the present project is the mechanichal analysis the left heart in healthy and diseased subjects joined with an approach based on Modern Shape Analysis in order to unveil stabilities (i.e. physiological changes) and irregularities (i.e. pathophysiological changes) across a wide range of conditions including both healthy condition and a relatively broad spectrum of pathologies thus including volume- and pressure overload.
The analysis of the interplay between pvc diagram and global changes of shape (to be intended in a statistical sense) is new and, to the best of our knowledge, never implemented. It is true that the idea to create a morphometric atlas can be traced back to the ¿90 years when morphometric atlas of skulls or other hard parts of human body started to be developed. However, the Atlas we are planning to elaborate is a completely different object being a collection of elements, each of them being a shape corresponding to the global behavior of a left heart all along the cardiac cycle. This makes it worth as it says something about heart functionality in a dynamic sense. It is important not to confuse shapes which are the object of MSA with shapes which are also objects of Mechanics: the first ones inherit their characteristics from the behavior of the heart along the cardiac cycle; the second ones can only represent the geometry of the left hearts at different instants of the same cycle.
Developing patient-specific digital heart models and establishing a unified foundation for in silico cardiovascular medicine is a target of many Groups all around the world, as evidenced in the previous section. The final target is leading cardiovascular researchers, medical device manufacturers, regulatory agencies, and practicing cardiologists on the shared mission to develop and validate digital human heart models.
The common elements of the different Groups, including our own, are their high interdisciplinarity, due to the translational character of the topic, the availability of a well-done database comprehensive of healthy persons and patients, the skills required to build a mechanical/electromechanical heart model, the implementation of the digital human heart model into a strong computational infrastructure.
In the past years, we developed our skills looking for methods allowing theidentification of a synthetic way to address cardiac function in healthy versus pathological situations, with reference to the left ventricle or to the whole left heart, thus including the left atrium. To get it, we developed an original methodology based on MSA to look at image-based clinical studies. It allowed to extract from the echocardiographic images taken by the Clinicians of our Group a few mathematically and mechanically quantifiable key global features of the heart motion, with the idea to successively establish the mechanical model of the heart on such elements.
Now, as a last step, we¿ll build a morphometric Atlas of the heart what has never been build. It can provide support in distinguishing the parameters in a patient-specific digital heart model which affect heart functionality. It can help in pre-operative planning as well as in diagnosing pathological lesions and in projecting patient-specific 3D printed implants. In this sense, the morphometric Atlas built on the digital database we developed in the past years of funded research, is a great challenge that can greatly help obtaining a major breakthrough in the mechanics of the heart.
It is worth noting that, during the last years, our long-term project highlighted the role of morphometric analysis in cardiac mechanics as evidenced by the viewpoint below cited and published on a high rank scientific Journal as a comment to a recent publication of our group:
¿In this issue of Experimental Physiology, Piras et al. (2019) elegantly load geometric morphometrics and four-dimensional trajectory analysis onto three-dimensional speckle tracking echo-cardiography to characterize myocardial deformation in a brand new way¿
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