Authors: R H Anderson, N A Brown

BACKGROUND

There is a marked conservative tendency to be found in anatomic descriptions, with a seeming reluctance on the part of acknowledged experts to test new theories by returning to direct studies of gross anatomy. This tendency has become manifest to us during recent attempts to review the structure and function of the heart.

METHODS

We have reviewed our recent experience in trying to describe the structure and development of the atrial septum and arterial roots, attempting at the same time to establish the place of semantic as opposed to morphologic factors in disagreements on these topics.

RESULTS

Dissection of the structures separating the right atrium from the left atrium shows a fundamental difference between the infolded superior rim of the oval foramen, made up of the atrial walls, versus the make up of the sinus and atrioventricular septums, which are true septal structures. Analysis of the arterial roots shows that the major feature is the semilunar attachment of the valvar leaflets, an arrangement not ideally described in terms of an annulus.

CONCLUSIONS

Understanding of details of cardiac anatomy, as set out in standard textbooks, is hindered by a reluctance on the part of some to accept material presented on the basis of straightforward gross dissection. Instead, there is a seeming desire to depend on conventional wisdom, often unsupported by anatomic fact. Such controversies can be ameliorated by appropriate recognition to contributions of gross morphology and by using simple words to describe the observed anatomic features.

Topics: Anatomy; Arteries; Coronary Vessels; Heart; Heart Septum; Heart Valves; Humans; Terminology as Topic

PubMed: 8876818
DOI: 10.1002/(SICI)1097-0185(199609)246:1<1::AID-AR1>3.0.CO;2-Y

Comparative Study

Authors: S J Crick, M N Sheppard, S Y Ho...

Transgenic technology has potentially solved many of the immunological difficulties of using pig organs to support life in the human recipient. Nevertheless, other problems still remain. Knowledge of cardiac anatomy of the pig (Sus scrofa) is limited despite the general acceptance in the literature that it is similar to that of man. A qualitative analysis of porcine and human cardiac anatomy was achieved by gross examination and dissection of hearts with macrophotography. The porcine organ had a classic 'Valentine heart' shape, reflecting its location within the thorax and to the orientation of the pig's body (unguligrade stance). The human heart, in contrast, was trapezoidal in silhouette, reflecting man's orthograde posture. The morphologically right atrium of the pig was characterised by the tubular shape of its appendage (a feature observed on the left in the human heart). The porcine superior and inferior caval veins opened into the atrium at right angles to one another, whereas in man the orifices were directly in line. A prominent left azygous vein (comparable to the much reduced left superior caval or oblique vein in man) entered on the left side of the pig heart and drained via the coronary sinus. The porcine left atrium received only 2 pulmonary veins, whereas 4 orifices were generally observed in man. The sweep between the inlet and outlet components of the porcine right ventricle was less marked than in man, and a prominent muscular moderator band was situated in a much higher position within the porcine right ventricle compared with that of man. The apical components of both porcine ventricles possessed very coarse trabeculations, much broader than those observed in the human ventricles. In general, aortic-mitral fibrous continuity was reduced in the outlet component of the porcine left ventricle, with approximately two-thirds of the aortic valve being supported by left ventricular musculature. Several potentially significant differences exist between porcine and human hearts. It is important that these differences are considered as the arguments continue concerning the use of transgenic pig hearts for xenotransplantation.

Topics: Adult; Animals; Animals, Newborn; Coronary Vessels; Dissection; Heart; Heart Atria; Heart Ventricles; Humans; Infant, Newborn; Radiography; Swine

PubMed: 9758141
DOI: 10.1046/j.1469-7580.1998.19310105.x

Review

Authors: Lingjuan He, Kathy O Lui, Bin Zhou...

Understanding how coronary blood vessels form and regenerate during development and progression of cardiac diseases will shed light on the development of new treatment options targeting coronary artery diseases. Recent studies with the state-of-the-art technologies have identified novel origins of, as well as new, cellular and molecular mechanisms underlying the formation of coronary vessels in the postnatal heart, including collateral artery formation, endocardial-to-endothelial differentiation and mesenchymal-to-endothelial transition. These new mechanisms of coronary vessel formation and regeneration open up new possibilities targeting neovascularization for promoting cardiac repair and regeneration. Here, we highlight some recent studies on cellular mechanisms of coronary vessel formation, and discuss the potential impact and significance of the findings on basic research and clinical application for treating ischemic heart disease.

Topics: Animals; Cell Differentiation; Cell Lineage; Coronary Vessels; Endocardium; Endothelium; Heart; Heart Diseases; Humans; Myocardial Ischemia; Neovascularization, Physiologic; Organogenesis; Pericardium; Regeneration; Stem Cells

PubMed: 31636078
DOI: 10.1101/cshperspect.a037168

Review

Authors: Vineesh Kappadan, Anies Sohi, Ulrich Parlitz...

Optical mapping is a widely used tool to record and visualize the electrophysiological properties in a variety of myocardial preparations such as Langendorff-perfused isolated hearts, coronary-perfused wedge preparations, and cell culture monolayers. Motion artifact originating from the mechanical contraction of the myocardium creates a significant challenge to performing optical mapping of contracting hearts. Hence, to minimize the motion artifact, cardiac optical mapping studies are mostly performed on non-contracting hearts, where the mechanical contraction is removed using pharmacological excitation-contraction uncouplers. However, such experimental preparations eliminate the possibility of electromechanical interaction, and effects such as mechano-electric feedback cannot be studied. Recent developments in computer vision algorithms and ratiometric techniques have opened the possibility of performing optical mapping studies on isolated contracting hearts. In this review, we discuss the existing techniques and challenges of optical mapping of contracting hearts.

Topics: Action Potentials; Heart; Myocardium

PubMed: 36866700
DOI: 10.1113/JP283683

Review

Authors: Laura Dyer, Xinchun Pi, Cam Patterson...

The establishment of the coronary circulation is one of the final critical steps during heart development. Despite decades of research, our understanding of how the coronary vasculature develops and connects to the aorta remains limited. This review serves two specific purposes: it addresses recent advances in understanding the origin of the coronary endothelium, and it then focuses on the last crucial step of coronary vasculature development, the connection of the coronary plexus to the aorta. The chick and quail animal models have yielded most of the information for how these connections form, starting with a fine network of vessels that penetrate the aorta and coalesce to form two distinct ostia. Studies in mouse and rat confirm that at least some of these steps are conserved in mammals, but gaps still exist in our understanding of mammalian coronary ostia formation. The signaling cues necessary to guide the coronary plexus to the aorta are also incompletely understood. Hypoxia-inducible transcription factor-1 and its downstream targets are among the few identified genes that promote the formation of the coronary stems. Together, this review summarizes our current knowledge of coronary vascular formation and highlights the significant gaps that remain. In addition, it highlights some of the coronary artery anomalies known to affect human health, demonstrating that even seemingly subtle defects arising from incorrect coronary plexus formation can result in significant health crises.

Topics: Animals; Coronary Vessels; Endothelium, Vascular; Gene Expression Regulation, Developmental; Heart; Humans; Models, Anatomic; Models, Cardiovascular; Stem Cells

PubMed: 25173872
DOI: 10.1016/j.ydbio.2014.08.024

Review

Authors: Tharusha Gunawardena, Ioannis Merinopoulos, Upul Wickramarachchi...

The fervency for advancement and evolution in percutaneous coronary intervention has revolutionised the treatment of coronary artery disease. Historically, the focus of the interventional cardiologist was directed at the restoration of luminal patency of the major epicardial coronary arteries, yet whilst this approach is evolving with much greater utilisation of physiological assessment, it often neglects consideration of the role of the coronary microcirculation, which has been shown to clearly influence prognosis. In this review, we explore the narrative of the coronary circulation as more than just a simple conduit for blood but an organ with functional significance. We review organisation and physiology of the coronary circulation, as well as the current methods and techniques used to examine it. We discuss the studies exploring coronary artery endothelial function, appreciating that coronary artery disease occurs on a spectrum of disorder and that percutaneous coronary intervention has a latent effect on the coronary circulation with long-term consequences. It is concluded that greater recognition of the coronary artery endothelium and mechanisms of the coronary circulation should further guide revascularisation strategies.

Topics: Coronary Artery Disease; Coronary Circulation; Endothelium, Vascular; Heart; Humans; Percutaneous Coronary Intervention

PubMed: 32552654
DOI: 10.2174/1573403X16666200618161942

Review

Authors: Bailey Dye, Joy Lincoln

Endocardial cells are specialized endothelial cells that, during embryogenesis, form a lining on the inside of the developing heart, which is maintained throughout life. Endocardial cells are an essential source for several lineages of the cardiovascular system including coronary endothelium, endocardial cushion mesenchyme, cardiomyocytes, mural cells, fibroblasts, liver vasculature, adipocytes, and hematopoietic cells. Alterations in the differentiation programs that give rise to these lineages has detrimental effects, including premature lethality or significant structural malformations present at birth. Here, we will review the literature pertaining to the contribution of endocardial cells to valvular, and nonvalvular lineages and highlight critical pathways required for these processes. The lineage differentiation potential of embryonic, and possibly adult, endocardial cells has therapeutic potential in the regeneration of damaged cardiac tissue or treatment of cardiovascular diseases.

Topics: Animals; Embryonic Development; Endocardial Cushions; Endocardium; Heart Valves; Humans; Myocardium; Signal Transduction

PubMed: 31988139
DOI: 10.1101/cshperspect.a036723

Review

Authors: Ravi Namani, Yoram Lanir, Lik Chuan Lee...

The oxygen consumption by the heart and its extraction from the coronary arterial blood are the highest among all organs. Any increase in oxygen demand due to a change in heart metabolic activity requires an increase in coronary blood flow. This functional requirement of adjustment of coronary blood flow is mediated by coronary flow regulation to meet the oxygen demand without any discomfort, even under strenuous exercise conditions. The goal of this article is to provide an overview of the theoretical and computational models of coronary flow regulation and to reveal insights into the functioning of a complex physiological system that affects the perfusion requirements of the myocardium. Models for three major control mechanisms of myogenic, flow, and metabolic control are presented. These explain how the flow regulation mechanisms operating over multiple spatial scales from the precapillaries to the large coronary arteries yield the myocardial perfusion characteristics of flow reserve, autoregulation, flow dispersion, and self-similarity. The review not only introduces concepts of coronary blood flow regulation but also presents state-of-the-art advances and their potential to impact the assessment of coronary microvascular dysfunction (CMD), cardiac-coronary coupling in metabolic diseases, and therapies for angina and heart failure. Experimentalists and modelers not trained in these models will have exposure through this review such that the nonintuitive and highly nonlinear behavior of coronary physiology can be understood from a different perspective. This survey highlights knowledge gaps, key challenges, future research directions, and novel paradigms in the modeling of coronary flow regulation.

Topics: Coronary Circulation; Heart; Hemodynamics; Homeostasis; Humans; Models, Cardiovascular; Myocardial Contraction

PubMed: 32142361
DOI: 10.1152/ajpheart.00563.2019

Review

Authors: Nurmakhan Zholshybek, Zaukiya Khamitova, Bauyrzhan Toktarbay...

BACKGROUND

Physical activity contributes to changes in cardiac morphology, which are known as "athlete's heart". Therefore, these modifications can be characterized using different imaging modalities such as echocardiography, including Doppler (flow Doppler and Doppler myocardial imaging) and speckle-tracking, along with cardiac magnetic resonance, and cardiac computed tomography.

MAIN TEXT

Echocardiography is the most common method for assessing cardiac structure and function in athletes due to its availability, repeatability, versatility, and low cost. It allows the measurement of parameters like left ventricular wall thickness, cavity dimensions, and mass. Left ventricular myocardial strain can be measured by tissue Doppler (using the pulse wave Doppler principle) or speckle tracking echocardiography (using the two-dimensional grayscale B-mode images), which provide information on the deformation of the myocardium. Cardiac magnetic resonance provides a comprehensive evaluation of cardiac morphology and function with superior accuracy compared to echocardiography. With the addition of contrast agents, myocardial state can be characterized. Thus, it is particularly effective in differentiating an athlete's heart from pathological conditions, however, is less accessible and more expensive compared to other techniques. Coronary computed tomography is used to assess coronary artery anatomy and identify anomalies or diseases, but its use is limited due to radiation exposure and cost, making it less suitable for young athletes. A novel approach, hemodynamic forces analysis, uses feature tracking to quantify intraventricular pressure gradients responsible for blood flow. Hemodynamic forces analysis has the potential for studying blood flow within the heart and assessing cardiac function.

CONCLUSIONS

In conclusion, each diagnostic technique has its own advantages and limitations for assessing cardiac adaptations in athletes. Examining and comparing the cardiac adaptations resulting from physical activity with the structural cardiac changes identified through different diagnostic modalities is a pivotal focus in the field of sports medicine.

Topics: Humans; Cardiomegaly, Exercise-Induced; Heart; Echocardiography; Myocardium; Heart Ventricles; Athletes

PubMed: 38098064
DOI: 10.1186/s12947-023-00319-3

Authors: Yutang Wang, Kate M Denton

Cardiovascular diseases (CVDs) constitute a spectrum of disorders affecting the heart and blood vessels, which include coronary heart disease, cerebrovascular disease, and peripheral artery disease [...].

Topics: Humans; Cardiovascular Diseases; Heart; Sympathetic Nervous System; Cerebrovascular Disorders; Coronary Disease

PubMed: 38473880
DOI: 10.3390/ijms25052633