Although the heart atria have a lesser functional importance than the ventricles, atria play an important role in the pathophysiology of heart failure and supraventricular arrhythmias, particularly atrial fibrillation. In addition, knowledge of atrial morphology recently became more relevant as cardiac electrophysiology and interventional procedures in the atria gained an increasingly significant role in the clinical management of patients with heart disease. The atrial chambers are thin-walled, and several vessels enter at the level of the atria. The left and right atrium have different structures and shape. In general, both atrial chambers have the venous part, the appendage, and the vestibule; different aspects of each part allow us to distinguish morphologically between the left and right atrium. The human atrial conduction system consists of the sinus node and the atrioventricular node with no histologically specialized conduction pathways in the atrial chamber and an interatrial connection. The data show that the propagation of the impulse depends mainly on the myocardial architecture in the atria and the orientation of the myocytes plays a significant role in conduction. To complete the picture, it is also important to know how the atria develop and what is the embryonic origin of its different structures, as this may play a role in the development of some pathological conditions such as atrial fibrillation or certain types of congenital heart defects. Functional impairment of the atria can in some situations severely compromise heart pumping function, and conversely, can support it if other areas are damaged, balancing the blood flow to the body for some time. Key words Morphology of atrial chambers, Pectinate muscles, Atrial function.

• MeSH
• lidé MeSH
• převodní systém srdeční * fyziologie   MeSH
• srdce - funkce síní * fyziologie   MeSH
• srdeční síně * embryologie   anatomie a histologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Atrioventricular (AV) accessory pathways (APs) provide additional electrical connections between the atria and ventricles, resulting in severe electrical disturbances. It is generally accepted that APs originate in the altered annulus fibrosus maturation in the late prenatal and perinatal period. However, current experimental methods cannot address their development in specific locations around the annulus fibrosus because of the inaccessibility of late fetal hearts for electrophysiological investigation under physiological conditions. In this study, we describe an approach for optical mapping of the retrogradely perfused chick heart in the last third of the incubation period. This system showed stability for electrophysiological measurement for several hours. This feature allowed analysis of the number and functionality of the APs separately in each clinically relevant position. Under physiological conditions, we also recorded the shortening of the AV delay with annulus fibrosus maturation and analyzed ventricular activation patterns after conduction through APs at specific locations. We observed a gradual regression of AP with an area-specific rate (left-sided APs disappeared first). The results also revealed a sudden drop in the number of active APs between embryonic days 16 and 18. Accessory myocardial AV connections were histologically documented in all positions around the annulus fibrosus even after hatching. The fact that no electrically active AP was present at this stage highlights the necessity of electrophysiological evaluation of accessory atrioventricular connections in studying AP formation.NEW & NOTEWORTHY We present the use of retrograde perfusion and optical mapping to investigate, for the first time, the regression of accessory pathways during annulus fibrosus maturation, separately examining each clinically relevant location. The system enables measurements under physiological conditions and demonstrates long-lasting stability compared with other approaches. This study offers applications of the model to investigate electrical and/or functional development in late embryonic development without concern about heart viability.

• Klíčová slova
• Langendorff perfusion, atrioventricular accessory pathway, preexcitation,
• MeSH
• akční potenciály * MeSH
• kuřecí embryo MeSH
• nodus atrioventricularis embryologie   patofyziologie   MeSH
• perfuze MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

A well-developed heart is essential for embryonic survival. There are constant interactions between cardiac tissue motion and blood flow, which determine the heart shape itself. Hemodynamic forces are a powerful stimulus for cardiac growth and differentiation. Therefore, it is particularly interesting to investigate how the blood flows through the heart and how hemodynamics is linked to a particular species and its development, including human. The appropriate patterns and magnitude of hemodynamic stresses are necessary for the proper formation of cardiac structures, and hemodynamic perturbations have been found to cause malformations via identifiable mechanobiological molecular pathways. There are significant differences in cardiac hemodynamics among vertebrate species, which go hand in hand with the presence of specific anatomical structures. However, strong similarities during development suggest a common pattern for cardiac hemodynamics in human adults. In the human fetal heart, hemodynamic abnormalities during gestation are known to progress to congenital heart malformations by birth. In this chapter, we discuss the current state of the knowledge of the prenatal cardiac hemodynamics, as discovered through small and large animal models, as well as from clinical investigations, with parallels gathered from the poikilotherm vertebrates that emulate some hemodynamically significant human congenital heart diseases.

• Klíčová slova
• Axolotl, Chick embryo, DORV, Developing myocardium, ET1, Embryogenesis, Endothelin 1, Fetal heart, Guinea pig, HLHS, Hemodynamics, Hyperplasia, Hypertrophy, Hypoplastic left heart syndrome, KLF2, Krüppel-like factor 2, Lamb, Mouse, NOS3, Nitric oxide synthase 3, Pressure overload, Rat, Reptile, VSD, Volume overload, Zebrafish,
• MeSH
• hemodynamika * fyziologie   MeSH
• lidé MeSH
• srdce * růst a vývoj   fyziologie   MeSH
• vrozené srdeční vady patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

In 2023, six decades have elapsed since the first experimental work on the heart muscle was published, in which a member of the Institute of Physiology of the Czech Academy of Sciences participated as an author; Professor Otakar Poupa was the founder and protagonist of this research domain. Sixty years - more than half of the century - is certainly significant enough anniversary that is worth looking back and reflecting on what was achieved during sometimes very complicated periods of life. It represents the history of an entire generation of experimental cardiologists; it is possible to learn from its successes and mistakes. The objective of this review is to succinctly illuminate the scientific trajectory of an experimental cardiological department over a 60-year span, from its inaugural publication to the present. The old truth - historia magistra vitae - is still valid. Keywords: Heart, Adaptation, Development, Hypoxia, Protection.

• MeSH
• akademie a ústavy * dějiny   MeSH
• biomedicínský výzkum * dějiny   trendy   MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• fyziologie dějiny   MeSH
• kardiologie dějiny   trendy   MeSH
• lidé MeSH
• srdce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• přehledy MeSH
• Geografické názvy
• Česká republika MeSH

The mammalian ventricular myocardium forms a functional syncytium due to flow of electrical current mediated in part by gap junctions localized within intercalated disks. The connexin (Cx) subunit of gap junctions have direct and indirect roles in conduction of electrical impulse from the cardiac pacemaker via the cardiac conduction system (CCS) to working myocytes. Cx43 is the dominant isoform in these channels. We have studied the distribution of Cx43 junctions between the CCS and working myocytes in a transgenic mouse model, which had the His-Purkinje portion of the CCS labeled with green fluorescence protein. The highest number of such connections was found in a region about one-third of ventricular length above the apex, and it correlated with the peak proportion of Purkinje fibers (PFs) to the ventricular myocardium. At this location, on the septal surface of the left ventricle, the insulated left bundle branch split into the uninsulated network of PFs that continued to the free wall anteriorly and posteriorly. The second peak of PF abundance was present in the ventricular apex. Epicardial activation maps correspondingly placed the site of the first activation in the apical region, while some hearts presented more highly located breakthrough sites. Taken together, these results increase our understanding of the physiological pattern of ventricular activation and its morphological underpinning through detailed CCS anatomy and distribution of its gap junctional coupling to the working myocardium.

• Klíčová slova
• cardiac conduction system, connexin, immunohistochemistry, myocardium, optical mapping,
• MeSH
• konexin 43 fyziologie   MeSH
• mezerový spoj fyziologie   MeSH
• mezibuněčná komunikace * MeSH
• myši MeSH
• perikard cytologie   fyziologie   MeSH
• Purkyňova vlákna cytologie   fyziologie   MeSH
• srdeční komory patologie   MeSH
• svalové buňky cytologie   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• GJA1 protein, mouse MeSH Prohlížeč
• konexin 43 MeSH