Cardiac Helical Function

2020 ◽  
Author(s):  
Jorge Trainini ◽  
Jorge Lowenstein ◽  
Mario Beraudo ◽  
Mario Wernicke ◽  
Vicente Mora Llabata ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Initial Period ◽  
Three Dimensional ◽  
Electrical Activation ◽  
Histological Structure ◽  
Great Resistance ◽  
Diastolic Phase ◽  
The Right ◽  
Ventricular Twist ◽  
Ventricular Filling

Abstract 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

Hemodynamic correlates of the fourth heart sound

1961 ◽  
Vol 201 (6) ◽  
pp. 1090-1094 ◽  
Author(s):  
G. Muiesan ◽  
D. M. MacCanon ◽  
D. Nunez-Dey ◽  
G. Di Bartolo
Keyword(s):  
Left Atrial ◽  
Cardiac Cycle ◽  
Heart Sound ◽  
Electrical Activation ◽  
Late Component ◽  
Left Heart ◽  
Atrial Contraction ◽  
Pressure Peak ◽  
The Right ◽  
Ventricular Filling

Intracardiac phonocardiographic characteristics of the atrial sounds and the relation of these vibrations to mechanical and electrical events of the cardiac cycle were studied in 21 dogs. Simultaneous recordings of intracardiac (from RA, LA, RV, and LV) and external phonocardiograms and equisensitive intracardiac pressures confirmed that the atrial sound is commonly formed by two main sets of vibrations: the first coincident with the onset of the atrial "a" wave, the second with its highest pressure peak. It is suggested that the first group of vibrations is usually due to atrial contraction and the second to ventricular filling. A short reversal of presystolic AV pressures after atrial relaxation occurred in some of the cases, suggesting that here a valvular mechanism was involved in the production of the late component of the atrial sound. The rapid intravenous infusion of saline generally increased the amplitude of the atrial sound and made evident the presence of a second component. The administration of drugs inducing systemic or pulmonary hypertension failed to give consistent changes in the amplitude and timing of the atrial sound. An asynchronism between right and left atrial sounds was demonstrated, the right-sided presystolic vibrations preceding those of the left heart by 0.026 sec (AS1) and 0.023 sec (AS2), respectively, in accordance with the earlier electrical activation and contraction of the right atrium.

Noninvasive high-resolution electromyometrial imaging of uterine contractions in a translational sheep model

2019 ◽  
Vol 11 (483) ◽  
pp. eaau1428 ◽  
Author(s):  
Wenjie Wu ◽  
Hui Wang ◽  
Peinan Zhao ◽  
Michael Talcott ◽  
Shengsheng Lai ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Electrical Activation ◽  
Current Clinical Practice ◽  
Sheep Model ◽  
Activation Patterns ◽  
Uterine Contractions ◽  
Spatial Specificity ◽  
Uterine Electrical Activity ◽  
Pressure Catheter

In current clinical practice, uterine contractions are monitored via a tocodynamometer or an intrauterine pressure catheter, both of which provide crude information about contractions. Although electrohysterography/electromyography can measure uterine electrical activity, this method lacks spatial specificity and thus cannot accurately measure the exact location of electrical initiation and location-specific propagation patterns of uterine contractions. To comprehensively evaluate three-dimensional uterine electrical activation patterns, we describe here the development of electromyometrial imaging (EMMI) to display the three-dimensional uterine contractions at high spatial and temporal resolution. EMMI combines detailed body surface electrical recording with body-uterus geometry derived from magnetic resonance images. We used a sheep model to show that EMMI can reconstruct uterine electrical activation patterns from electrodes placed on the abdomen. These patterns closely match those measured with electrodes placed directly on the uterine surface. In addition, modeling experiments showed that EMMI reconstructions are minimally affected by noise and geometrical deformation. Last, we show that EMMI can be used to noninvasively measure uterine contractions in sheep in the same setup as would be used in humans. Our results indicate that EMMI can noninvasively, safely, accurately, robustly, and feasibly image three-dimensional uterine electrical activation during contractions in sheep and suggest that similar results might be obtained in clinical setting.

scholarly journals Right-sided Bochdalek hernia in an adult with hepatic malformation and intestinal malrotation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Naoki Enomoto ◽  
Kazuhiko Yamada ◽  
Daiki Kato ◽  
Shusuke Yagi ◽  
Hitomi Wake ◽  
...  
Keyword(s):  
Elective Surgery ◽  
Abdominal Cavity ◽  
Three Dimensional ◽  
Simulation Software ◽  
3D Simulation ◽  
Diaphragmatic Defect ◽  
Intestinal Malrotation ◽  
Intestinal Loop ◽  
Bochdalek Hernia ◽  
The Right

Abstract Background Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely.

scholarly journals Alteration within the Hippocampal Volume in Patients with LHON Disease—7 Tesla MRI Study

2020 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Cezary Grochowski ◽  
Kamil Jonak ◽  
Marcin Maciejewski ◽  
Andrzej Stępniewski ◽  
Mansur Rahnama-Hezavah
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Molecular Layer ◽  
Three Dimensional ◽  
Hippocampal Volume ◽  
7 Tesla ◽  
Diagnostic Process ◽  
Resonance Imaging ◽  
The Right

Purpose: The aim of this study was to assess the volumetry of the hippocampus in the Leber’s hereditary optic neuropathy (LHON) of blind patients. Methods: A total of 25 patients with LHON were randomly included into the study from the national health database. A total of 15 patients were selected according to the inclusion criteria. The submillimeter segmentation of the hippocampus was based on three-dimensional spoiled gradient recalled acquisition in steady state (3D-SPGR) BRAVO 7T magnetic resonance imaging (MRI) protocol. Results: Statistical analysis revealed that compared to healthy controls (HC), LHON subjects had multiple significant differences only in the right hippocampus, including a significantly higher volume of hippocampal tail (p = 0.009), subiculum body (p = 0.018), CA1 body (p = 0.002), hippocampal fissure (p = 0.046), molecular layer hippocampus (HP) body (p = 0.014), CA3 body (p = 0.006), Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)–GC ML DG body (p = 0.003), CA4 body (p = 0.001), whole hippocampal body (p = 0.018), and the whole hippocampus volume (p = 0.023). Discussion: The ultra-high-field magnetic resonance imaging allowed hippocampus quality visualization and analysis, serving as a powerful in vivo diagnostic tool in the diagnostic process and LHON disease course assessment. The study confirmed previous reports regarding volumetry of hippocampus in blind individuals.

Right Atrial Thrombosis and Pulmonary Embolism: A Narrative Review

2020 ◽  
Vol 46 (08) ◽  
pp. 895-907
Author(s):  
Nina D. Anfinogenova ◽  
Oksana Y. Vasiltseva ◽  
Alexander V. Vrublevsky ◽  
Irina N. Vorozhtsova ◽  
Sergey V. Popov ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Embolism ◽  
High Risk ◽  
Transesophageal Echocardiography ◽  
Three Dimensional ◽  
Right Atrial ◽  
Treatment Protocols ◽  
High Risk Patients ◽  
Risk Patients ◽  
The Right

AbstractPrompt diagnosis of pulmonary embolism (PE) remains challenging, which often results in a delayed or inappropriate treatment of this life-threatening condition. Mobile thrombus in the right cardiac chambers is a neglected cause of PE. It poses an immediate risk to life and is associated with an unfavorable outcome and high mortality. Thrombus residing in the right atrial appendage (RAA) is an underestimated cause of PE, especially in patients with atrial fibrillation. This article reviews achievements and challenges of detection and management of the right atrial thrombus with emphasis on RAA thrombus. The capabilities of transthoracic and transesophageal echocardiography and advantages of three-dimensional and two-dimensional echocardiography are reviewed. Strengths of cardiac magnetic resonance imaging (CMR), computed tomography, and cardiac ventriculography are summarized. We suggest that a targeted search for RAA thrombus is necessary in high-risk patients with PE and atrial fibrillation using transesophageal echocardiography and/or CMR when available independently on the duration of the disease. High-risk patients may also benefit from transthoracic echocardiography with right parasternal approach. The examination of high-risk patients should involve compression ultrasonography of lower extremity veins along with the above-mentioned technologies. Algorithms for RAA thrombus risk assessment and protocols aimed at identification of patients with RAA thrombosis, who will potentially benefit from treatment, are warranted. The development of treatment protocols specific for the diverse populations of patients with right cardiac thrombosis is important.

scholarly journals Three-Dimensional Printable Hydrogel Using a Hyaluronic Acid/Sodium Alginate Bio-Ink

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 794 ◽  
Author(s):  
Su Jeong Lee ◽  
Ji Min Seok ◽  
Jun Hee Lee ◽  
Jaejong Lee ◽  
Wan Doo Kim ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Hyaluronic Acid ◽  
Sodium Alginate ◽  
Three Dimensional ◽  
Fibroblast Cell ◽  
Chemical Crosslinking ◽  
Fibroblast Cell Line ◽  
Engineering Applications ◽  
Encapsulated Cells ◽  
Crosslinking Agents

Bio-ink properties have been extensively studied for use in the three-dimensional (3D) bio-printing process for tissue engineering applications. In this study, we developed a method to synthesize bio-ink using hyaluronic acid (HA) and sodium alginate (SA) without employing the chemical crosslinking agents of HA to 30% (w/v). Furthermore, we evaluated the properties of the obtained bio-inks to gauge their suitability in bio-printing, primarily focusing on their viscosity, printability, and shrinkage properties. Furthermore, the bio-ink encapsulating the cells (NIH3T3 fibroblast cell line) was characterized using a live/dead assay and WST-1 to assess the biocompatibility. It was inferred from the results that the blended hydrogel was successfully printed for all groups with viscosities of 883 Pa∙s (HA, 0% w/v), 1211 Pa∙s (HA, 10% w/v), and 1525 Pa∙s, (HA, 30% w/v) at a 0.1 s−1 shear rate. Their structures exhibited no significant shrinkage after CaCl2 crosslinking and maintained their integrity during the culture periods. The relative proliferation rate of the encapsulated cells in the HA/SA blended bio-ink was 70% higher than the SA-only bio-ink after the fourth day. These results suggest that the 3D printable HA/SA hydrogel could be used as the bio-ink for tissue engineering applications.

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
Clinical Situation ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

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