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Circulation Journal : Official Journal... Mar 2017Endomyocardial biopsy (EMB) has been established in parallel with the development of percutaneous catheter technology for the diagnosis of cardiac diseases. It was... (Review)
Review
Endomyocardial biopsy (EMB) has been established in parallel with the development of percutaneous catheter technology for the diagnosis of cardiac diseases. It was developed in the early 1960 s in Japan by Drs. Konno, Sakakibara and Sekiguchi of Tokyo Women's Medical University. EMB is a valuable and useful, but invasive, modality for making a definite diagnosis in diseases such as myocarditis and secondary cardiomyopathies, which are often difficult to diagnose by imaging modality alone. In the field of heart transplantation, the histology of EMB helps monitor rejection to allografts. In cases of chronic heart failure, fibrosis and degeneration of cardiomyocytes are very important findings of heart remodeling. Recently, molecular biology technology has been applied to EMB specimens to get more detailed information. However, we must also recognize that EMB is an invasive examination that should not be performed without skillful cardiac catheterization experience to avoid complications. In this review as a message from pathologists, we present key cardiac histopathology using EMB, in a way that allows one to imagine whole cardiac pathological conditions. We also describe the current role of EMB and its significance in order to encourage young cardiologists to perform EMB to see another world of pathology.
Topics: Biopsy; Cardiomyopathies; Endocardium; Heart Diseases; Humans; Myocarditis; Myocardium
PubMed: 28331134
DOI: 10.1253/circj.CJ-16-0927 -
Circulation Research Feb 2022Unraveling how new coronary arteries develop may provide critical information for establishing novel therapeutic approaches to treating ischemic cardiac diseases. There...
BACKGROUND
Unraveling how new coronary arteries develop may provide critical information for establishing novel therapeutic approaches to treating ischemic cardiac diseases. There are 2 distinct coronary vascular populations derived from different origins in the developing heart. Understanding the formation of coronary arteries may provide insights into new ways of promoting coronary artery formation after myocardial infarction.
METHODS
To understand how intramyocardial coronary arteries are generated to connect these 2 coronary vascular populations, we combined genetic lineage tracing, light sheet microscopy, fluorescence micro-optical sectioning tomography, and tissue-specific gene knockout approaches to understand their cellular and molecular mechanisms.
RESULTS
We show that a subset of intramyocardial coronary arteries form by angiogenic extension of endocardium-derived vascular tunnels in the neonatal heart. Three-dimensional whole-mount fluorescence imaging showed that these endocardium-derived vascular tunnels or tubes adopt an arterial fate in neonates. Mechanistically, we implicate Mettl3 (methyltransferase-like protein 3) and Notch signaling in regulating endocardium-derived intramyocardial coronary artery formation. Functionally, these intramyocardial arteries persist into adulthood and play a protective role after myocardial infarction.
CONCLUSIONS
A subset of intramyocardial coronary arteries form by extension of endocardium-derived vascular tunnels in the neonatal heart.
Topics: Animals; Coronary Vessels; Endocardium; Methyltransferases; Mice; Mice, Inbred C57BL; Organogenesis
PubMed: 34995101
DOI: 10.1161/CIRCRESAHA.121.320335 -
Journal of the American College of... May 2017
Topics: Cardiomyopathies; Endocardium; Humans; Tachycardia
PubMed: 28449779
DOI: 10.1016/j.jacc.2017.03.536 -
The Journal of Cell Biology Jun 2022Tissue-resident macrophages play essential functions in the maintenance of tissue homeostasis and repair. Recently, the endocardium has been reported as a de novo...
Tissue-resident macrophages play essential functions in the maintenance of tissue homeostasis and repair. Recently, the endocardium has been reported as a de novo hemogenic site for the contribution of hematopoietic cells, including cardiac macrophages, during embryogenesis. These observations challenge the current consensus that hematopoiesis originates from the hemogenic endothelium within the yolk sac and dorsal aorta. Whether the developing endocardium has such a hemogenic potential requires further investigation. Here, we generated new genetic tools to trace endocardial cells and reassessed their potential contribution to hematopoietic cells in the developing heart. Fate-mapping analyses revealed that the endocardium contributed minimally to cardiac macrophages and circulating blood cells. Instead, cardiac macrophages were mainly derived from the endothelium during primitive/transient definitive (yolk sac) and definitive (dorsal aorta) hematopoiesis. Our findings refute the concept of endocardial hematopoiesis, suggesting that the developing endocardium gives rise minimally to hematopoietic cells, including cardiac macrophages.
Topics: Animals; Aorta; Cell Lineage; Endocardium; Heart; Hematopoiesis; Macrophages; Myocardium; Yolk Sac
PubMed: 35482005
DOI: 10.1083/jcb.202108093 -
The International Journal of... 2009The vertebrate heart is unique among the blood pumps described in metazoans. In contrast to the myoepithelial tubes found in most animal phyla, the vertebrate heart is... (Review)
Review
The vertebrate heart is unique among the blood pumps described in metazoans. In contrast to the myoepithelial tubes found in most animal phyla, the vertebrate heart is made up of multilayered myocardial cells surrounded by connective tissue derived from epicardium and endocardium, and endowed with complex valvular, coronary vessel and conduction systems. Despite these profound differences, a common genetic program seems to underlie the specification and differentiation of all the cardiac tissues. In this article, we will review the similarities in the transcriptional networks and signalling mechanisms regulating cardiac development in different animals, as well as the origin of the main differences existing between vertebrate and invertebrate hearts. We will pay special attention to the hypotheses concerning the evolutionary origin of the endothelium and the epicardium from ancestral blood cells and pronephric progenitors, respectively. We can summarize the transition between the invertebrate and the vertebrate heart as the result of the thickening of the primarily myoepithelial cardiac tube which was concomitant with: 1) an inner lining by an endothelium with the ability to transform into mesenchyme; 2) an outer lining derived from an ancestral pronephric glomerular primordium with vasculogenic potential; 3) a neural crest cell population which reaches the heart from the pharyngeal region; 4) the incorporation of new myocardium at both ends from a second heart field and 5) the formation of specialized chambers. The complex interactions between all these elements originated an exceptionally powerful blood pump which allowed vertebrates to reach their characteristically large size and activity.
Topics: Animals; Biological Evolution; Body Patterning; Endocardium; Gene Expression Regulation, Developmental; Heart; Models, Biological; Myocardium; Pericardium; Vertebrates
PubMed: 19247975
DOI: 10.1387/ijdb.072409jp -
Pacing and Clinical Electrophysiology :... Jan 2011Electrophysiological properties of the atrial endocardium compared to epicardium are not well understood. The purpose of this study was to compare the... (Comparative Study)
Comparative Study
BACKGROUND
Electrophysiological properties of the atrial endocardium compared to epicardium are not well understood. The purpose of this study was to compare the electrophysiological properties and vulnerability to arrhythmia induction from these regions.
METHODS AND RESULTS
Transseptal endocardial and percutaneous epicardial mapping were performed in a porcine model (n = 7). Two opposing 4-mm electrophysiological catheters were positioned endocardially and epicardially. A circular mapping catheter (CMC) was positioned at the ostium of the common inferior pulmonary vein (CIPV) recording left atrial (LA)-PV potentials. Endocardial and epicardial effective refractory periods (ERPs) at two basic cycle lengths (CLs) of 600 and 400 ms were recorded from four anatomic locations (CIPV, LA appendage, right superior PV, and LA posterior wall). Atrial repetitive response (ARR) induction was also tested from endocardial and epicardial sites. Overall, 254 ERP measurements (mean 36.3 per animal) and 84 induction attempts (mean 12 per animal) were performed. The ERP was significantly shorter in the epicardium compared to the endocardium at basic CL of 400 ms (P = 0.006) but not at CL of 600 ms (P = 0.2). In addition, only the epicardium demonstrated ERP shortening when the CL of the basic drive was shortened (P = 0.03). ARR could be induced more often from the epicardium (P = 0.002) and fibrillatory activity with epicardial/endocardial dissociation was recorded (n = 3). Also, the earliest PV activation site on the CMC was noted to be different in 16.5% of cases during epicardial and endocardial pacing.
CONCLUSION
The electrophysiological characteristics of the atrial epicardium are different from the endocardium with a shorter ERP and more frequent ARR induction by programed stimulation.
Topics: Action Potentials; Animals; Atrial Function; Cardiac Pacing, Artificial; Endocardium; Heart Conduction System; Pericardium; Swine
PubMed: 20946283
DOI: 10.1111/j.1540-8159.2010.02892.x -
Interactive Cardiovascular and Thoracic... Jun 2021The aim of this study was to evaluate the lesion size and depth of radiofrequency (RF) ablation in a simultaneous biparietal bidirectional bipolar (SBB) approach,...
OBJECTIVES
The aim of this study was to evaluate the lesion size and depth of radiofrequency (RF) ablation in a simultaneous biparietal bidirectional bipolar (SBB) approach, compared to a simultaneous and staged unipolar and uniparietal bipolar setup [simultaneous uniparietal bipolar (SiUB) and staged uniparietal bipolar (StUB), respectively].
METHODS
Fresh left atrial porcine tissue was mounted into the ABLA-BOX simulator. Different ablation approaches were tested: (i) SBB: a concept consisting of SBB endo-epicardial ablation, (ii) SiUB: simultaneous epicardial uniparietal bipolar and endocardial unipolar ablation and (iii) StUB: staged epicardial uniparietal bipolar and endocardial unipolar ablation. In the StUB setup, a 1-h interval between the epi-endo ablation was respected.
RESULTS
Transmural lesions were present in 90% of the bipolar biparietal ablations, yet no full transmurality was observed in the simultaneous nor in the staged unipolar with uniparietal bipolar ablation group. In SBB, the area and volume of the ablation lesions were smaller (523.33 mm2/mm and 52.33 mm3/mm, respectively) than in SiUB (588.17 mm2/mm and 58.81 mm3/mm, respectively) and StUB (583.76 mm2/mm and 58.37 mm3/mm, P = 0.044). Also, in SBB, the overall, epicardial and endocardial maximum diameters of the lesions (1.59, 1.57 and 1.52 mm; respectively) were smaller than in SiUB (2.38, 2.26 and 2.33 mm; respectively) and in StUB (2.36, 2.28 and 2.14 mm; respectively, all P < 0.001).
CONCLUSIONS
Although bipolar biparietal bidirectional RF ablation results in smaller lesions than uniparietal bipolar and unipolar ablation, their capacity to penetrate the tissue is much higher. Moreover, in uniparietal RF applications, the energy spreads in the superficial layers of the tissue but fails to penetrate. Therefore, the degree of transmurality is much higher when using such a 'truly bipolar' ablation approach.
Topics: Animals; Atrial Fibrillation; Catheter Ablation; Endocardium; Heart Atria; Swine
PubMed: 33611536
DOI: 10.1093/icvts/ivab047 -
Current Topics in Developmental Biology 2019Heart formation involves a complex series of tissue rearrangements, during which regions of the developing organ expand, bend, converge, and protrude in order to create... (Review)
Review
Heart formation involves a complex series of tissue rearrangements, during which regions of the developing organ expand, bend, converge, and protrude in order to create the specific shapes of important cardiac components. Much of this morphogenesis takes place while cardiac function is underway, with blood flowing through the rapidly contracting chambers. Fluid forces are therefore likely to influence the regulation of cardiac morphogenesis, but it is not yet clear how these biomechanical cues direct specific cellular behaviors. In recent years, the optical accessibility and genetic amenability of zebrafish embryos have facilitated unique opportunities to integrate the analysis of flow parameters with the molecular and cellular dynamics underlying cardiogenesis. Consequently, we are making progress toward a comprehensive view of the biomechanical regulation of cardiac chamber emergence, atrioventricular canal differentiation, and ventricular trabeculation. In this review, we highlight a series of studies in zebrafish that have provided new insight into how cardiac function can shape cardiac morphology, with a particular focus on how hemodynamics can impact cardiac cell behavior. Over the long-term, this knowledge will undoubtedly guide our consideration of the potential causes of congenital heart disease.
Topics: Animals; Biomechanical Phenomena; Body Fluids; Cell Differentiation; Endocardial Cushions; Endocardium; Gene Expression Regulation, Developmental; Heart; Morphogenesis; Zebrafish
PubMed: 30797515
DOI: 10.1016/bs.ctdb.2018.12.009 -
The National Medical Journal of India 1993
Review
Topics: Biopsy; Echocardiography; Endocardium; Endomyocardial Fibrosis; Humans; Mitral Valve; Palliative Care; Tricuspid Valve
PubMed: 7694719
DOI: No ID Found -
The Annals of Thoracic Surgery Jan 2006
Comparative Study
Topics: Acute Disease; Animals; Atrial Fibrillation; Disease Models, Animal; Dose-Response Relationship, Radiation; Electrocoagulation; Endocardium; Heart Atria; Heart Ventricles; Humans; Microwaves; Pericardium; Sus scrofa; Time Factors
PubMed: 16368339
DOI: 10.1016/j.athoracsur.2005.08.040