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Journal of Artificial Organs : the... Apr 2024Impella is a mechanical circulatory support device of a catheter-based intravascular microaxial pump for left ventricular support and unloading. However, nonclinical...
Impella is a mechanical circulatory support device of a catheter-based intravascular microaxial pump for left ventricular support and unloading. However, nonclinical studies assessing the effects of the extended duration of left ventricular unloading on cardiac recovery are lacking. An animal model using Impella implanted with a less invasive procedure to enable long-term support is required. This study aimed to evaluate the feasibility of an animal model for long-term support with Impella 5.5 implanted through carotid artery access in sheep.Impella 5.5 was implanted in four sheep through the proximal region of the left carotid artery without a thoracotomy, and myocardial injuries were induced by coronary microembolization. Support by Impella 5.5 was maintained for 4 weeks, and the animals were observed. The position of Impella 5.5 and cardiac function was evaluated using cardiac computer tomography at 2 and 4 weeks after implantation.All four animals completed the 4-week study without major complications. The discrepancy in the Impella 5.5 flow rate between the conscious and anesthetized states was observed depending on the device's position. Animals in whom the inflow was above the left ventricular papillary muscle had a relatively high flow rate under the maximum performance level without a suction alarm during the conscious state. Pathological changes in the aortic valve were observed. Cardiac function under the minimum performance level was observed with no remarkable deterioration.The animal model with myocardial injuries supported for 4 weeks by Impella 5.5 implanted through carotid artery access in sheep was feasible.
PubMed: 38642185
DOI: 10.1007/s10047-024-01444-0 -
Tissue & Cell Jun 2024Our research aims to conduct a comprehensive ultrastructural, histochemical, and immunohistochemical examination of Tarentola annularis' tongue, utilizing various...
Lingual adaptations of the Tarentola annularis with new insights into its papillary system adaptations: Ultrastructure, histochemistry, and immunohistochemical observations.
Our research aims to conduct a comprehensive ultrastructural, histochemical, and immunohistochemical examination of Tarentola annularis' tongue, utilizing various techniques such as light, scanning electron microscopy, and morphometric analysis. The complex papillary system consisted of four conical subtypes and one filiform type. The apex carried three conical subtypes (elongated, quadrilateral, and round); the midtongue carried two papillary types (quadrilateral conical and rectangular pointed filiform); and the hindtongue carried two conical subtypes (quadrilateral and elongated serrated). The dorsal papillary surface carried little taste pores on the foretongue and taste buds on the midtongue. The foretongue had a slightly stratum corneum that spread to coat the papillae, while the mid- and hindtongue did not. The glands are absent from the foretongue but are found in the interpapillary spaces of the mid- and hindtongue. Histochemical analysis reveals the presence of collagen fibers in the muscle bundles and the papillary core. The midtongue glands exhibited a strong reaction to AB and PAS, while the hindtongue showed moderate AB positivity and strong positive PAS. The cytokeratin expression in the foretongue papilla was positive, whereas the papillae in other regions were negative. The Tarentola annularis exhibits distinctive lingual structural characteristics due to its varied feeding habits influenced by available food particles.
Topics: Animals; Tongue; Immunohistochemistry; Taste Buds; Adaptation, Physiological
PubMed: 38640599
DOI: 10.1016/j.tice.2024.102366 -
Journal of Anatomy Apr 2024Despite centuries of investigation, certain aspects of left ventricular anatomy remain either controversial or uncertain. We make no claims to have resolved these... (Review)
Review
Despite centuries of investigation, certain aspects of left ventricular anatomy remain either controversial or uncertain. We make no claims to have resolved these issues, but our review, based on our current knowledge of development, hopefully identifies the issues requiring further investigation. When first formed, the left ventricle had only inlet and apical components. With the expansion of the atrioventricular canal, the developing ventricle cedes part of its inlet to the right ventricle whilst retaining the larger parts of the cushions dividing the atrioventricular canal. Further remodelling of the interventricular communication provides the ventricle with its outlet, with the aortic root being transferred to the left ventricle along with the newly formed myocardium supporting its leaflets. The definitive ventricle possesses inlet, apical and outlet parts. The inlet component is guarded by the mitral valve, with its leaflets, in the normal heart, supported by papillary muscles located infero-septally and supero-laterally. There is but a solitary zone of apposition between the leaflets, which we suggest are best described as being aortic and mural. The trabeculated component extends beyond the inlet to the apex and is confluent with the outlet part, which supports the aortic root. The leaflets of the aortic valve are supported in semilunar fashion within the root, with the ventricular cavity extending to the sinutubular junction. The myocardial-arterial junction, however, stops well short of the sinutubular junction, with myocardium found only at the bases of the sinuses, giving rise to the coronary arteries. We argue that the relationships between the various components should now be described using attitudinally appropriate terms rather than describing them as if the heart is removed from the body and positioned on its apex.
PubMed: 38629319
DOI: 10.1111/joa.14048 -
Journal of Muscle Research and Cell... Apr 2024We examined the integrity of flash-frozen and cryo-sectioned cardiac muscle preparations (introduced by Feng and Jin, 2020) by assessing tension transients in response...
Biomechanical evaluation of flash-frozen and cryo-sectioned papillary muscle samples by using sinusoidal analysis: cross-bridge kinetics and the effect of partial Ca activation.
We examined the integrity of flash-frozen and cryo-sectioned cardiac muscle preparations (introduced by Feng and Jin, 2020) by assessing tension transients in response to sinusoidal length changes at varying frequencies (1-100 Hz) at 25 °C. Using 70-μm-thick sections, we isolated fiber preparations to study cross-bridge (CB) kinetics: preparations were activated by saturating Ca as well as varying concentrations of ATP and phosphate (Pi). Our results showed that, compared to ordinary skinned fibers, in-series stiffness decreased to 1/2, which resulted in a decrease of isometric tension to 62%, but CB kinetics and Ca sensitivity were little affected. The pCa study demonstrated that the rate constant of the force generation step (2πb) is proportionate to [Ca] at < 5 μM, suggesting that the activation mechanism can be described by a simple second order reaction. We also found that tension, stiffness, and magnitude parameters are related to [Ca] by the Hill equation, with a cooperativity coefficient of 4-5, which is consistent with the fact that Ca activation mechanisms involve cooperative multimolecular interactions. Our results support the long-held hypothesis that Process C (Phase 2) represents the CB detachment step, and Process B (Phase 3) represents the force generation step. Moreover, we discovered that constant H may represent the work-performing step in cardiac preparations. Our experiments demonstrate excellent CB kinetics with two well-defined exponentials that can be more distinguished than those found using ordinary skinned fibers. Flash-frozen and cryo-sectioned preparations are especially suitable for multi-institutional collaborations nationally and internationally because of their ease of transportation.
PubMed: 38625452
DOI: 10.1007/s10974-024-09667-7 -
Molecular and Cellular Endocrinology Aug 2024High sucrose intake is linked to cardiovascular disease, a major global cause of mortality worldwide. Calcium mishandling and inflammation play crucial roles in cardiac...
INTRODUCTION
High sucrose intake is linked to cardiovascular disease, a major global cause of mortality worldwide. Calcium mishandling and inflammation play crucial roles in cardiac disease pathophysiology.
OBJECTIVE
Evaluate if sucrose-induced obesity is related to deterioration of myocardial function due to alterations in the calcium-handling proteins in association with proinflammatory cytokines.
METHODS
Wistar rats were divided into control and sucrose groups. Over eight weeks, Sucrose group received 30% sucrose water. Cardiac function was determined in vivo using echocardiography and in vitro using papillary muscle assay. Western blotting was used to detect calcium handling protein; ELISA assay was used to assess TNF-α and IL-6 levels.
RESULTS
Sucrose led to cardiac dysfunction. RYR2, SERCA2, NCX, pPBL Ser16 and L-type calcium channels were unchanged. However, pPBL-Thr17, and TNF-α levels were elevated in the S group.
CONCLUSION
Sucrose induced cardiac dysfunction and decreased myocardial contractility in association with altered pPBL-Thr17 and elevated cardiac pro-inflammatory TNF-α.
Topics: Animals; Male; Rats; Calcium-Binding Proteins; Interleukin-6; Myocardial Contraction; Myocardium; Phosphorylation; Rats, Wistar; Sucrose; Tumor Necrosis Factor-alpha
PubMed: 38608803
DOI: 10.1016/j.mce.2024.112236 -
Catheterization and Cardiovascular... Jun 2024The use of left atrial appendage occlusion (LAAO) devices have gained prominence as an alternative to long-term anticoagulation therapy in patients with atrial...
The use of left atrial appendage occlusion (LAAO) devices have gained prominence as an alternative to long-term anticoagulation therapy in patients with atrial fibrillation at risk of stroke and high risk of bleeding. While these devices have shown efficacy in reducing stroke risk, there have been reported cases of embolization of the Watchman device. There are very few cases of successful percutaneous retrieval of embolized Watchman devices from the left ventricle (LV), as many of these cases require open heart surgery for safe removal. We are presenting a case of an 80-year-old male whose Watchman device embolized to the LV and was entrapped on the LV papillary muscle that was then successfully retrieved via percutaneous methods, which shows the percutaneous options remain a viable strategy to retrieve LAAO devices from the LV.
Topics: Humans; Male; Aged, 80 and over; Device Removal; Treatment Outcome; Atrial Fibrillation; Cardiac Catheterization; Foreign-Body Migration; Papillary Muscles; Heart Ventricles; Embolism; Atrial Appendage; Echocardiography, Transesophageal
PubMed: 38606476
DOI: 10.1002/ccd.31049 -
European Journal of Cardio-thoracic... Mar 2024Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering...
OBJECTIVES
Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering follows. We previously reported a new technique of the right ventricular papillary muscle approximation (RV-PMA) for functional TR associated with leaflet tethering. The objective of this study is to elucidate the mid-term outcomes and evaluate the durability of RV-PMA.
METHODS
Between January 2014 and March 2023, we applied RV-PMA in 20 patients of advanced functional TR with severe leaflet tethering. The indication of the technique was severe TR with leaflet tethering height >8 mm, and/or a right ventricular end-diastolic diameter >45 mm. The patients were followed up with echocardiography before discharge and at annual interval thereafter.
RESULTS
There was no perioperative mortality. In the echocardiography performed before discharge, TR was decreased to mild or less in 85%, and a significant improvement in right ventricular end-diastolic diameter and tethering height were achieved (53-45 mm and 11.1-4.4 mm, respectively). Furthermore, during the median 3-year follow-up period, TR was kept controlled mild or less in 80% of the cases.
CONCLUSIONS
RV-PMA is considered to be a safe, effective and durable technique as an additional approach for tricuspid annuloplasty.
Topics: Humans; Tricuspid Valve Insufficiency; Papillary Muscles; Male; Female; Aged; Middle Aged; Heart Ventricles; Treatment Outcome; Echocardiography; Cardiac Valve Annuloplasty; Retrospective Studies; Tricuspid Valve; Severity of Illness Index; Follow-Up Studies
PubMed: 38603618
DOI: 10.1093/ejcts/ezae151 -
Frontiers in Cardiovascular Medicine 2024Mitral annular disjunction (MAD) refers to the arrhythmic mitral valve prolapse (MVP) syndrome associated with ventricular arrhythmias and sudden cardiac death. Although...
BACKGROUND
Mitral annular disjunction (MAD) refers to the arrhythmic mitral valve prolapse (MVP) syndrome associated with ventricular arrhythmias and sudden cardiac death. Although the pathophysiology of this disease is still under investigation, specific imaging criteria that establish the diagnosis have been recognized. In this article, we demonstrate most of these criteria using three-dimensional transthoracic echocardiography (3D-TTE) and provide added value in the management of MAD syndrome.
CASE PRESENTATION
A 50-year-old male patient with recent syncope and a history of mitral regurgitation (MR) and MAD was admitted to our clinic for further investigation. According to our protocol, the patient underwent a complete 3D-TTE, laboratory blood exams, and 24 h ambulatory electrocardiogram (ECG). Our investigation confirmed the presence of MAD syndrome with bileaflet prolapse, severe MR, and non-sustained ventricular tachycardia, necessitating an implantable cardioverter defibrillator (ICD) and surgical mitral valve repair. The 3D-TTE analysis of the mitral valve demonstrated mitral annular systolic expansion and systolic flattening of the saddle-shaped annulus and quantified the extent of the disjunction arc. Additionally, four-dimensional (4D) strain analysis of the left ventricle revealed the presence of fibrosis of the posteromedial papillary muscle and basal inferolateral wall, which are variables that are required for the diagnosis and therapeutic management of MAD syndrome.
CONCLUSIONS
3D-TTE and 4D strain offer valuable insights for diagnosing and managing patients with MAD syndrome. This method seems to correlate well with the other imaging modalities and could be included in the management protocol of MAD syndrome.
PubMed: 38601046
DOI: 10.3389/fcvm.2024.1366444 -
Cardiology Apr 2024With the implementation of early reperfusion therapy, the number of complications in patients with acute coronary syndrome (ACS) has diminished significantly. However,...
INTRODUCTION
With the implementation of early reperfusion therapy, the number of complications in patients with acute coronary syndrome (ACS) has diminished significantly. However, ACS patients are still routinely admitted to units with high-level monitoring such as the coronary or intensive care unit (CCU/ICU). The cost of these admissions is high and there is often a shortage of beds. The aim of this study was to analyze the complications in contemporary emergency department (ED) patients with ACS and to map patient management.
METHODS
This observational study was a secondary analysis of data collected in the ESC-TROP trial (NCT03421873) that included 26,545 consecutive chest pain patients ≥18 years at five Swedish EDs. Complications were defined as the following within 30 days: death, cardiac arrest, cardiogenic shock, pulmonary edema, severe ventricular arrhythmia, high-degree atrioventricular (AV) block that required a pacemaker, and mechanical complications such as papillary muscle rupture, cardiac tamponade, or ventricular septum defects (VSDs). Complications were identified via diagnosis and/or intervention codes in the database, and manual chart review was performed in cases with complications.
RESULTS
Of all 26,545 patients, 2,463 (9.3%) were diagnosed with ACS, and 151 of these (6.1%) suffered any complication within 30 days. Mean age was higher in patients with (79.2 years) than without (69.4 years) complications, and more were female (39.7% vs. 33.0%). Eighty-four (3.4% of all ACS patients) patients died, 33 (1.3%) had cardiac arrest, 22 (0.9%) respiratory failure, 13 (0.5%) high-degree AV block, 10 (0.4%) cardiogenic shock, 12 (0.5%) severe ventricular arrhythmia, and 2 each (<0.1%) had VSD or cardiac tamponade. Almost 30% of the complications were present already at the ED, and 40% of patients with complications were not admitted to the CCU/ICU. Only 80 (53%) of the patients with complications underwent coronary angiography and 62 (41%) were revascularized with percutaneous coronary intervention or coronary artery bypass grafting.
CONCLUSION
With current care, serious complications occurred in only 6 out of 100 ACS patients, and 2 of these complications were present already at the ED. Four out of 10 ACS patients with complications were not admitted to the CCU/ICU and about half did not undergo coronary angiography. Further research is needed to improve risk assessment in ED ACS patients, which may allow more effective use of cardiac monitoring and hospital resources.
PubMed: 38599184
DOI: 10.1159/000538637 -
JA Clinical Reports Apr 2024Left ventricular (LV) decompression is an essential strategy for improving early survival in patients with refractory cardiogenic shock. Low pump flow in patients on...
Anterolateral papillary muscle suction causing low flow in a COVID-19 patient without medical history: a case report of central extracorporeal life support with left ventricular apex decompression.
BACKGROUND
Left ventricular (LV) decompression is an essential strategy for improving early survival in patients with refractory cardiogenic shock. Low pump flow in patients on extracorporeal life support (ECLS) with LV apex decompression is a life-threatening issue. However, identifying the underlying causes of low flow can be challenging.
CASE PRESENTATION
A 38-year-old woman with COVID-19-related fulminant myocarditis was treated with central ECLS with LV apex decompression. The pump flow in the intensive care unit (ICU) was intermittently low, and low flow alerts were frequent. The initial evaluation based on pressure monitor waveforms and transthoracic echocardiography failed to identify the underlying cause. Prompt bedside transesophageal echocardiography (TEE) revealed that the anterolateral papillary muscle was suctioned into the vent cannula of the LV apex during systole. The patient underwent a repeat sternal midline incision in the operating room, and the cannula at the LV apex was repositioned. There were no further suction events after the repositioning, and the patient was weaned from ECLS 12 days after admission to the ICU. The patient was discharged in a stable condition and without neurological deficits.
CONCLUSIONS
TEE is an important diagnostic tool to identify the underlying cause of low flow flow in patients undergoing ECLS with LV apex decompression.
PubMed: 38597982
DOI: 10.1186/s40981-024-00701-8