Myocardial torsion and cardiac fulcrum

Trainini, Jorge C.; Lowenstein, Jorge; Beraudo, Mario; Wernicke, Mario; Trainini, Alejandro; Llabata, Vicente Mora; Carreras, C.F.

doi:10.1016/j.morpho.2020.06.010

Cited by 20 publications

(23 citation statements)

References 6 publications

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“…Between aortic valve closure and mitral valve opening, there is an abrupt drop of intraventricular pressure with energy expenditure until reaching negative values (Figure 2). It is during this phase that muscle contraction of the ascending segment end in its insertion into the cardiac fulcrum elicits LV lengthening-detorsion with the closed chamber [3]. This was corroborated in our investigations in patients using three-dimensional electroanatomical mapping with Carto navigation and mapping system (Figure 3) [4,5].…”

Section: Introductionsupporting

confidence: 80%

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Cardiac Energy

Trainini¹,

Jesús²,

Francesc³

et al. 2022

CEI

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Introduction/Objectives: In the cardiac cycle, should a coupling phase be considered between systole and diastole where cardiac suction occurs? Shouldn't the left ventricular ejection fraction be considered a poor reliability index? According to these considerations, would it not be more logical to speak of cardiac energy of suction and ejection as parameters that summarize the cardiac potential and to which variables that are not independent would concur. Materials and Methods: The concept of energy is incorporated by means of a detailed evaluation of the cardiac ability developed by both ventricles as a counterpart of ejection fraction values to assess ventricular function. The heart in its pump function, presents a dynamic effect that is greater than the volume it ejects. Data involving patients will have informed consent. Results: Understanding the active mechanism of the suction phase as a link between systole and diastole opens a wide scenario on surgical techniques and medical treatments for many cardiac diseases that are still the focus of attention. Conclusion: The important incorporation of other disciplines such as physics and hydraulics has allowed the evaluation of cardiac mechanics from pre-existing laws that denote and justify what the heart really represents: a mechanical suction pump. The understanding of cardiac functions is achieved from the cardiac structure-function and from a physico/hydraulic point of view.

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Section: Introductionsupporting

confidence: 80%

“…There is asynchrony between the RV and the LV. In our investigations, the former contracts 12.4 ms before the left one [3]. This facilitates left ventricular suction after the end of right ventricular ejection, as the heart does not contract en bloc but in fractions of a continuous structural unit.…”

Section: Congestionmentioning

confidence: 58%

Cardiac Energy

Trainini¹,

Jesús²,

Francesc³

et al. 2022

CEI

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“…In this supporting site, the muscle bers 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. (18) This structural composition keeps correspondence with the activation of the myocardial band. The stimulus runs by its muscle pathways, but in order to ful ll the function proposed by its helical arrangement, it is essential for it to simultaneously activate the left ventricular descending and ascending segments.…”

Section: Discussionmentioning

confidence: 79%

“…This mechanism is explained by the persistence of the ascending segment contraction during the isovolumic diastolic phase. (16)(17)(18)(19)(20)(21)(22) We have found that the endocardium is completely depolarized during the rst part of the QRS. 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).…”

Section: Resultsmentioning

confidence: 99%

Cardiac Helical Function

Jorge

Lowenstein²,

Beraudo³

et al. 2020

Preprint

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Background. The aim of this study was to investigate: a) the starts and ends of the myocardial band; b) the slippage between the band segments, when performing both torsion and ventricular detorsion, implies that there should be an antifriction mechanism that avoids dissipating the energy; c) the electrical activation of the endocardial and epicardial bands and secondarily understand ventricular twist and the mechanism of active suction during the diastolic isovolumic phase. Methods. They were used: a) Ten young-bovine hearts (800-1000 g) and seven human hearts (one embrión, 4 g; one 10 years, 250 g and five adult, 300 g/average); b) five patients with no structural cardiac abnormalities and normal QRS complexes underwent three-dimensional endoepicardial electroanatomic mapping. Results. We have found in all the bovine and human hearts studied a nucleus (fulcrum) underlying the right trigone, whose osseus, chondroid or tendinous histological structure depends on the specimen analyzed. All the hearts studied presented myocardial attachment to the rigid structure of the fulcrum. Hyaluronic acid was found in the cleavage planes between the myocardial bundles.Endo-epicardial mapping demonstrates an electrical activation sequence in the area of the apex loop in agreement with the synchronic contraction of the descending and ascending band segments, consistent with the mechanism of ventricular twist. The late activation of the ascending band segment is consistent with its persistent contraction during the initial period of the isovolumic diastolic phase (the basis of the suction mechanism). Conclusions. The finding of the fulcrum gives support to the spiral myocardial band being the point of fixation that allows the helicoidal torsion. The hyaluronic acid would act as a lubricant and provide great resistance to mechanical pressures. This study explains the ventricular twist and the active suction mechanism during the isovolumic diastolic and early ventricular filling phases.Trial. This work does not correspond to a trial

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“…Anecdotally, we calculated RV torsion in a case of congenital total absence of the pericardium (Supplementary Fig. wall and enters the septum [18,19]. In this study, global RV torsion was counterclockwise, to a smaller degree but in the same direction as the LV (Fig.…”

Section: Segmental Rv Torsionmentioning

confidence: 99%

Right Ventricular Segmental Rotation and Torsion in Normal Subjects on 2D Speckle Tracking Echocardiography

Yang¹,

Mookadam²,

Khandheria³

et al. 2022

Clin Ultrasound

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Background/Aims: Little is known about the complex anatomy of right ventricular (RV) torsion in the general population. This study was designed to assess RV’s global and segmental torsional motion in subjects without cardiac pathologies.Methods: We used the Vivid 7 ultrasound system (GE Healthcare, Chicago, IL, USA) to acquire parasternal short-axis views of the RV at the basal and apical levels, and analyzed global and segmental torsion using a 2D speckle tracking algorithm in EchoPAC workstation (GE Healthcare, Wauwatosa, WI, USA).Results: Forty-eight individuals (44 ± 17 years, 54% male) were included, with either normal left ventricular diastolic function (group I, n = 40) or grade I diastolic dysfunction (group II, n = 8). Group I showed global peak systolic torsion of 9.0 ± 6.6 degrees with higher segmental torsion in the mid-interventricular septum (IVS) than in the anterior walls (p = 0.001). Global RV torsion showed a very strong positive correlation with apical rotation (r = 0.91, p < 0.001). Group I exhibited higher segmental torsion in the anterior-IVS and mid-IVS walls than group II (9.8 ± 7.1 vs. 3.5 ± 9.6 degrees, p = 0.036; 10.4 ± 9.1 vs. 2.4 ± 12.3 degrees, p = 0.038, respectively).Conclusions: Analysis of RV segmental torsion was feasible using a 2D speckle tracking algorithm. Apical rotation can be used as a simplified index of global RV torsion. Further studies are needed to evaluate the clinical impact of RV torsion in various pathologies.

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Myocardial torsion and cardiac fulcrum

Cited by 20 publications

References 6 publications

Cardiac Energy

Cardiac Energy

Cardiac Helical Function

Right Ventricular Segmental Rotation and Torsion in Normal Subjects on 2D Speckle Tracking Echocardiography

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