China
Africa
Explore chapters and articles related to this topic
Autopsy Cardiac Examination
Published in Mary N. Sheppard, Practical Cardiovascular Pathology, 2022
Histology of the right atrium shows a thin wall which varies considerably depending on which area of the wall is looked at. The pectinate muscle is thick but in between the wall is almost transparent when held up to the light so thickness will also vary histologically (Fig. 1.45). The myocytes show marked variation in size admixed with fat and with prominent subendocardium (Fig. 1.46). Myocytes are isolated into bundles with variable orientation. In the thin transparent areas between pectinate muscle, the wall consists of collagen and scattered myocyte bundles. In the fossa ovalis, there is little residual myocytes, the fossa consisting mainly of collagen. As one goes towards the atrioventricular junction, the myocyte bundles are increasingly surrounded by collagen until at the junction there is complete separation by collagen from the right ventricle (Fig. 1.47). There is little or no epicardial fat in atrial epicardium which contains parallel bundles of collagen.
Isolated Atrial Preparations
Published in John H. McNeill, Measurement of Cardiac Function, 2020
M.K. Pugsley, E.S. Hayes, M.J.A. Walker
As described above, isolated atrial strips are usually obtained from larger species and include human atrial preparations obtained during open-heart surgery. In most cases, narrow strips of atrium are obtained through excision between the anterior vena cava and the atrio-ventricular groove. Usually tissue is obtained from the middle of the atrial wall with cuts parallel to the pectinate muscles. Isolated tissue from human subjects is usually obtained in the form of an approximately 1 cm2 atrial appendage removed as a part of the cannulation procedure for cardiopulmonary bypass.28 Atrial strips can be mounted in vertical or horizontal organ baths and attached to an appropriate recording device as described above. Atrial strips are often used in microelectrode studies of action potentials where they are mounted in horizontal tissue baths. Atrial strips from larger species are also suitable for measurement of atrial contractility.
Cardiac masses
Published in Andrew R. Houghton, MAKING SENSE of Echocardiography, 2013
Compared with a myxoma, a thrombus usually has a more irregular shape. Thrombus usually attaches to the endocardium via a broad base rather than a pedicle, and is consequently less mobile. A large proportion of LA thrombi are within the LA appendage, which can be difficult to inspect fully on TTE. The appendage is, however, clearly seen on TOE. It is important to try to distinguish between thrombus and the pectinate muscles, the normal muscle ridges found on the walls of both atria and the appendage. Pectinate muscles are immobile and run in bands; thrombus is usually more rounded and mobile.
Tricuspid Valve Dysplasia at Fetal Autopsy
Published in Fetal and Pediatric Pathology, 2022
Sumathi Shanmugam, Usha Nandhini Sennaiyan, Mani Ram Krishna
The autopsy was performed according to published guidelines [2]. There were no external anomalies. There was usual arrangement of the lungs and bronchial tree. The anterior abdomen was occupied by an enlarged liver. The thoracic cavity was dominated by an enlarged atrium. Both the lungs were pushed to the side (Fig. 1). On segmental analysis of the heart, the superior and inferior caval veins drained into an enlarged morphological right atrium with a pyramidal atrial appendage and extension of pectinate muscles beyond the appendage and all the way to the atrio-ventricular (A-V) groove (Fig. 2A). The pulmonary veins drained into the more posterior and left atrium with no pectinate muscle extension beyond the atrial appendage. There was a moderate sized atrial communication. The atrio-ventricular connections were concordant and there was right handed topology of the ventricles. The right A-V valve annulus was dilated. The anterior-superior, inferior and septal leaflets were not displaced from the A-V groove. However the leaflets were thickened with rolled-up edges (Fig. 2B). The left A-V valve was normal with morphologically normal aortic and mural leaflets. The inter-ventricular septum was intact and there was pulmonary valve aplasia. The aortic arch was left sided with normal branching pattern and an arterial duct was seen arising from the under surface of the arch to the pulmonary confluence. A diagnosis of tricuspid valve dysplasia with pulmonary artery atresia was established.
Left Atrial Appendage Closure Review: Addressing Unmet Needs of AF Mediated Stroke Prevention with Evolving Science
Published in Structural Heart, 2021
Anwar Tandar, Jack Nielsen, Brian K. Whisenant
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is projected to affect >12 million Americans by 2030.1,2 Stroke is the most debilitating complication of AF.3 The prevalence of AF among patients admitted with acute ischemic stroke has increased from 16% to 20% between 2003 and 2014. AF-related strokes are more disabling, more likely to recur, and are associated with higher mortality rates than non-AF-associated strokes.2 In atrial fibrillation, blood stagnates among left atrial appendage (LAA) pectinate muscles leading to thrombus and stroke.4 The LAA has been recognized as the source of AF-associated thrombus and stroke since 1949 and is the source of at least 90% of AF-associated thrombi.5 Left atrial thrombi independent of the appendage are largely reserved to patients with rheumatic heart disease and rheumatic, calcific, or post-surgical mitral stenosis.6 Chronic oral anticoagulation, usually with warfarin, remains the standard of care for patients with rheumatic heart disease and/or mitral stenosis.7
New developments in catheter ablation for patients with congenital heart disease
Published in Expert Review of Cardiovascular Therapy, 2021
Mathieu Le Bloa, Sylvia Abadir, Krishnakumar Nair, Blandine Mondésert, Paul Khairy
Once in the chamber of interest, real-time ultrasonic guidance may be helpful in [15]: Identifying anatomical structures that can prevent optimal catheter contact (e.g., prominent Eustachian ridge, pectinate muscle, pouches, recesses) and lead to gaps in linear ablation lesions;Visualizing the relationship between the mapping catheter and critical structures such as coronary arteries;Better visualizing the endocardial border [16], particularly with intravenous ultrasound contrast;Monitoring catheter stability during the ablation application;Early detection of potential complications such as pericardial effusion.