The autonomic nervous system and the origins of neurocardiology.

Following new concepts by Bichat in the early 19th century, of organic and animal life centered around the ganglionic nervous system, over 100 years of anatomic studies and physiologic experimentation eventually resulted in Gaskell's 1916 book entitled "The Involuntary Nervous System" and Langley's 1921 book entitled "The Autonomic Nervous System." Neurology and cardiology emerged as specialties of medicine in the early 20th century. Although neurology made several prominent discoveries in neurophysiology during the first half of the 20th century, cardiology developed coronary care units and cardiac catheterization in the 1960s. Programmed electrical stimulation of the heart and noninvasive ambulatory monitoring provided new methodologies to study clinical cardiac arrhythmias. Experimentally, direct cardiac nerve stimulation of sympathetic nerve endings, as well as parasympathetic control of the atrioventricular node, provided the background to new detailed autonomic studies of the heart. Neurocardiology, perhaps initially more directed towards our understanding of sudden cardiac death, ultimately embraced an even significantly more complex scheme of local circuit neurons and near-endless loops of interconnecting neurons in the heart. Intrathoracic extracardiac and intracardiac ganglia have been recharacterized, both anatomically and physiologically, laying the groundwork for potential new therapies of cardiac neuromodulation.

A modifiable valve-sparing pediatric cardiac dissection technique promotes specimen longevity and optimizes advanced image analysis postpathological examination.

This paper illustrates a valve-sparing cardiac dissection technique that keeps the atrioventricular and semilunar valves and other important cardiac structures intact. The technique minimizes disruption in heart specimens, so they remain suitable for teaching, demonstration, and further research. When performed following the perfusion-distension method of fixation, as our group previously described, this technique could optimize the preservation of heart specimens for teaching and digital archiving postdissection.

Incidence of quadricuspid pulmonary valves at postmortem examination.

Quadricuspid pulmonic valve is a rare congenital abnormality and because of its difficult non-invasive assessment, it is usually discovered incidentally at autopsies (reported prevalence in post-mortem specimens ranges from 1 in 400 to 1 in 2000). Unlike a bicuspid pulmonary valve, it rarely presents with clinical complications, such as valvular insufficiency or stenosis. Abnormal function is rarely reported in cases that are not associated with other congenital heart disease. With increased sophistication of imaging coincidental quadricuspid valves autopsy studies are important to understand the anatomical consequences of this finding. Our case series identified 21 QPV cases from the Victorian Institute of Forensic Medicine, Melbourne and St George's University of London, Department of Cardiovascular Pathology. Cases were identified through local database searches and review of autopsy/cardiac examination reports over a 20-year period. Available photographs were also systematically examined. Fifteen cases had causes of death with no direct causality to cardiac valvular pathology alone. Six cases were considered unascertained or similar (sudden arrhythmic death syndrome and sudden unexpected death in epilepsy). The presence of QPV in these instances were uncertain but thought to be unlikely contributory to death, due to the absence of pulmonary valvular complications.

Ventricular Epicardial Adipose Distribution on Human Hearts: 3-Dimensional Reconstructions and Quantitative Assessments.

Epicardial interventions have forged new frontiers in cardiac ablation and device therapies. Healthy human hearts typically present with significant adipose tissue layers superficial to the ventricular myocardium and may hinder success or increase the complexities of epicardial interventions. We quantitatively evaluated the distribution of epicardial adipose tissue on the surface of human hearts and provided high-fidelity 3-dimensional reconstructions of these epicardial adipose tissue layers. The regional thickness of adipose tissues was analyzed at 51 anatomical reference points surrounding both ventricles and compared to specific patient demographics. Adipose deposits on the human hearts displayed characteristic patterns, with the thickest accumulations along the interventricular septa (anterior, 9.01 ± 0.50 mm; posterior, 6.78 ± 0.50 mm) and the right ventricular margin (7.44 ± 0.57 mm). We provide one of the most complete characterizations of human epicardial adipose location and relative layer thickness. These results are considered fundamental for an underlying anatomic understanding when performing procedures within the pericardial space.

A 15-Year Experience With Total Anomalous Pulmonary Venous Connection in Vietnam.

BACKGROUND: This article aims to demonstrate the morphology of 261 total anomalous pulmonary venous connection (TAPVC) cases operated at Children's Hospital 1 with in-hospital mortality of 19.5% (51/261). METHODS: All the surgical protocols of TAPVC cases repaired between 2008 and June 2023 were reviewed. The descriptions of TAPVC were based on operative findings by surgeons. RESULTS: A total of 261 TAPVC patients were operated, including 124 (47.5%) supra, 83 (31.8%) intra, 41 (15.7%) infra, and 13 (5%) mixed cases. The in-hospital mortality was 19.5% (51/261). Fifteen cases are associated with other anomalies of the heart. Four subtypes of 124 supra TAPVC were found, with 42 (33.9%) obstructed cases. The standard was all pulmonary veins (PVs) forming a common vein (CV) and draining into the innominate veins, then going to the superior vena cava (SVC) (100/124, 80.6%). Eleven supra TAPVC cases were vascular vise type. Ten cases had the vertical vein running from the right of the CV and draining directly into the SVC. Of 83 intracardiac TAPVCs with 9 (10.8%) obstructed cases, the most common was all PVs draining directly into the coronary sinus (60/83, 72.3%). The second was all PVs draining directly into the right atrium (RA) via separated ostia or forming a CV before entering the RA (17/83, 20.5%). Also, there were three cases with rare variants and 100% obstruction when the diagnosis was explored. The in-hospital mortality of intracardiac type was 13.3% (11/83) 41 infra TAPVC with obstructed rate of 61% (25/41) and in-hospital mortality of 29.3% (12/41). Thirteen mixed TAPVCs were repaired, with most cases having three PVs forming a CV. CONCLUSION: This article provides valuable information about the morphology of TAPVC types in Asian patients.

Longitudinal Evaluation of Congenital Cardiovascular Surgical Performance and Skills Retention Using Silicone-Molded Heart Models.

Objective: Hands-on surgical training (HOST) for congenital heart surgery (CHS), utilizing silicone-molded models created from 3D-printing of patients' imaging data, was shown to improve surgical skills. However, the impact of repetition and frequency of repetition in retaining skills has not been previously investigated. We aimed to longitudinally evaluate the outcome for HOST on two example procedures of different technical difficulties with repeated attempts over a 15-week period. Methods: Five CHS trainees were prospectively recruited. Repair of coarctation of the aorta (CoA) and arterial switch operation (ASO) were selected as example procedures of relatively low and high technical difficulty. Procedural time and technical performance (using procedure-specific assessment tools by the participant, a peer-reviewer, and the proctor) were measured. Results: Coarctation repair performance scores improved after the first repetition but remained unchanged at the follow-up session. Likewise, CoA procedural time showed an early reduction but then remained stable (mean [standard deviation]: 29[14] vs 25[15] vs 23[9] min at 0, 1, and 4 weeks). Conversely, ASO performance scores improved during the first repetitions, but decreased after a longer time delay (>9 weeks). Arterial switch operation procedural time showed modest improvements across simulations but significantly reduced from the first to the last attempt: 119[20] versus 106[28] min at 0 and 15 weeks, P = .049. Conclusions: Complex procedures require multiple HOST repetitions, without excessive time delay to maintain long-term skills improvement. Conversely, a single session may be planned for simple procedures to achieve satisfactory medium-term results. Importantly, a consistent reduction in procedural times was recorded, supporting increased surgical efficiency.

Characteristics of Lambl excrescences of aortic and pulmonary valves in healthy hearts.

Lambl excrescences (LEs) were initially described in the mid-1800s during autopsies of human hearts, and their significance and biology have been debated ever since. LEs are typically found on aortic and pulmonary valve (semilunar) cusps. There is debate concerning whether LEs are a significant cause of thromboembolic events, or whether they are harmless growths. However, there have not been many reports discussing LEs, and fewer still have examined the prevalence and characteristics of LEs in healthy human hearts. Those who have examined LE prevalence have reported a very high incidence of LEs (85-90%). Herein, we examine LE prevalence and characteristics (size, location, number) in 403 healthy human hearts across all age groups. We find that the prevalence of LEs in healthy hearts is far lower than previously reported.

Operative Repair of Aortopulmonary Window: A 25-Year Experience.

Background: Aortopulmonary window (APW) is a rare anomaly with variable morphology and associated cardiac anomalies. We evaluated impact of patient and operative factors on mid-term outcomes following APW repair. Methods: Twenty-nine patients underwent surgical APW repair at our institution from 1996 to 2022. Eight (28%) had simple APW, accompanied by only atrial septal defect or patent ductus arteriosus; 21 (72%) had complex APW with additional cardiovascular lesions, including nine with interrupted aortic arch. Median operative age was 19 days (range 2 days-1.5 years) via single-patch (n = 12, 41%), double-patch (n = 15, 52%), or ligation and division (n = 2, 7%). Results: The only mortality occurred in-hospital 1.4 years postoperatively following remote myocardial infarction. Factors associated with longer postoperative length of stay were complex APW (P = .003), genetic syndrome (P = .003), noncardiovascular comorbidities (P = .002), lower birth weight (P = .03), and lower operative weight (P = .03). Six patients (21%) with complex APW underwent unplanned cardiothoracic reintervention(s), including two with arch reintervention following arch advancement for interruption. Reintervention-free survival was similar for simple versus complex APW, operative age categories, and repair techniques. At median follow-up 5.5 years postoperatively, no patients had residual APW or persistent pulmonary hypertension, 1 (3%) had greater than mild ventricular dysfunction, and 25 (89% survivors) had NYHA class I functional status. Conclusions: Operative APW repair has excellent mid-term survival, durability, and functional status, regardless of operative age, cardiovascular comorbidities, or repair technique. Cardiac and noncardiac comorbidities may be associated with prolonged length of stay.

A Triad of Intricacies: An Exploration of Concomitant Codominant Coronary Artery Pattern, Patent Foramen Ovale, and Chiari Network in a Cadaveric Study.

Although findings related to codominant coronary artery circulation, patent foramen ovale (PFO), and Chiari network (CN) have been documented in isolation, there is a gap in literature detailing the unique case with the presence of all three cardiac anomalies concomitantly present in a single heart. The purpose of this case report is to detail a unique cadaveric heart case, to serve as reference to provide useful data for interventionalists and clinicians. This observational cadaveric study assessed a single donor heart obtained through the University of Houston College of Medicine's Willed Donor Program. After meticulous dissection, relevant heart surface structures were isolated and identified. Morphometric analysis and measurements were obtained via a digital vernier caliper. The donor heart exhibited a typical codominant coronary arterial scheme, in that the posterior interventricular artery arose as a merger between the right coronary and the circumflex on the postero-inferior surface of the heart when placed in the valentine orientation. Interestingly, the antero-lateral surface of the heart was supplied via a left marginal artery (LMA) and an accessory left anterior interventricular artery.Contribution to the existing knowledge base of unique concomitant cardiac anomalies, may prove to be a beneficial future reference for interventionalists in hopes that an expanded knowledge base may lead to comprehensive and safe implementation of a wide variety of procedures.

Anomalous Left Circumflex Artery Arising From the Right Coronary Artery: A Cadaveric Case Report and Review of the Literature.

Coronary artery anomalies are relatively rare in the general population; however, they remain clinically significant due to their varying effects on cardiovascular function and diagnostic and treatment outcomes. Here is described an anomalous left circumflex artery (ALCx) discovered during routine dissection of a 76-year-old female anatomical donor. The ALCx was seen arising from shared ostia with the right coronary artery and conus artery from the right aortic sinus of Valsalva, giving off the left atrial branch along its retroaortic course before reaching the left aspect of the coronary sulcus. The left coronary artery took a traditional course, arising from the left aortic sinus of Valsalva before traveling in the anterior interventricular sulcus. A review of the literature was conducted to determine the incidence of ALCx and elucidate any associated clinical considerations. Though relatively rare, clinical awareness is necessary as evidence indicates ALCx, particularly the retroaortic portion, may be more prone to atherosclerosis, intimal proliferation, luminal occlusion, and increased ratio of necrotic core in atherosclerotic plaques. Imaging studies, including the aortic root sign on left ventriculography, can aid in the identification of ALCx. Awareness of ALCx and its potential influence on cardiac health is critical for the avoidance of diagnostic errors and adverse treatment outcomes. Through this case report, we seek to present the current evidence outlining the incidence of ALCx, as well as the literature surrounding its clinical implications.

El fulcro cardíaco y su relación con el nódulo auriculoventricular / Cardiac Fulcrum, its Relationship with the Atrioventricular Node

RESUMEN Introducción. El estudio de la anatomía funcional del miocardio helicoidal continuo permite visualizar su inicio y fin en el nacimiento de los grandes vasos. En nuestras investigaciones siempre hemos considerado que debía tener un punto de unión que permitiera su rotación helicoidal para cumplir los movimientos fundamentales de acortamiento-torsión (sístole) y alargamiento-destorsión (succión). Una vez encontrado, se le llamó fulcro cardíaco. Objetivos. Esta investigación tiene como objeto describir y entender la interrelación entre el fulcro cardíaco y el nódulo auriculoventricular de Aschoff-Tawara Material y métodos. Se utilizaron 31 corazones procedentes de la morgue y del matadero: 17 correspondieron a bóvidos y 14 a seres humanos. Resultados. En nuestras investigaciones hemos demostrado que el soporte del miocardio, denominado fulcro cardíaco, que se localiza en el trayecto del segmento septal del anillo aórtico y se extiende desde el trígono izquierdo hasta el derecho por debajo del origen de la arteria coronaria derecha, es adyacente al nódulo auriculoventricular (AV). Otro aspecto importante de esta posición contigua es que el fulcro está rodeado, e incluso invadido, por un plexo nervioso interconectado con el nódulo. Conclusión. Esta descripción del fulcro cardíaco pondría fin al problema de la falta de apoyo del miocardio para cumplir su función de torsión/destorsión. La proximidad del fulcro al nódulo AV y la penetración de los plexos nerviosos en el apoyo indican la existencia de una unidad electromecánica, que hemos investigado en función de la anatomía helicoidal del corazón. Hemos comprobado una mejor estimulación cardíaca cuando el catéter se coloca en el infundíbulo ventricular derecho.

ABSTRACT Background. The functional anatomy of the helical, continuous myocardium allows envisioning that it initiates and ends at the origin of the great vessels. In our research, we have always considered that it should have a point of attachment to allow its helical rotation to fulfill the fundamental movements of shortening-torsion (systole) and lengthening-detorsion (suction), which once found, was called the cardiac fulcrum. Objectives. The research aims to describe the important aspect of understanding the interrelationship between the cardiac fulcrum and the Aschoff-Tawara atrioventricular node Material and Methods. A total of 31 hearts, arising from the morgue and slaughterhouse were used: 17 corresponded to bovids and 14 were human. Results. Our investigations have shown that the myocardial support termed cardiac fulcrum, located in the trajectory of the aortic annulus septal segment, extending from the left to the right trigone and below the origin of the right coronary artery, is adjacent to the AV node. Another important aspect of this contiguous position is that the fulcrum is surrounded, and even invaded, by a rich nervous plexus interconnected with the node. Conclusion. This description of the cardiac fulcrum would end the problem of lack of support of the myocardium to fulfill its function of torsion/detorsion. The proximity of the fulcrum to the AV node and the penetration of the nervous plexuses in the support suggest an electromechanical unit, which we have investigated according to the helical anatomy of the heart, establishing an improved cardiac stimulation with a catheter placed in the right ventricular outflow tract.

El soporte del miocardio / Myocardial support

RESUMEN Objetivo: El músculo cardíaco no puede estar anatómicamente libre en el tórax y sin un soporte para cumplir con su función hemodinámica. Por tanto, se analizó la posibilidad de la existencia de un punto de apoyo que actuara a modo de palanca. Material y métodos: Se utilizaron: 1) disección cardíaca en diez corazones bovinos jóvenes (dos años) (800-1000 g); 2) disección cardíaca en ocho corazones humanos: un embrión de 23 semanas de gestación; uno de 10 años, 250 g; y seis adultos, peso medio 300 g. La banda miocárdica se desenrolló en su totalidad. Las piezas extraídas fueron analizadas por anatomía e histología. Se completó la investigación con estudios de imágenenes radiograficas simples, resonancia nuclear magnética y tomografia computada. Resultados: En investigaciones anatómicas hemos encontrado en todos los corazones humanos y bovinos estudiados un núcleo subyacente al trígono derecho de estructura histológica ósea-condroide-tendinosa. El análisis microscópico reveló en corazones bovinos una matriz osteocondral trabecular (fulcro). En todos los corazones humanos se encontró que el fulcro se halla formado por tejido condroide. En esta estructura, no descrita por otros autores, tienen inserción muscular el origen y el final de las fibras miocárdicas. Las técnicas con imágenes confirmaron su existencia. Conclusiones: El fulcro cardíaco encontrado en la investigación anatómica de corazones humanos y bovinos aclararía sobre el necesario punto de apoyo del músculo miocárdico para completar sus movimientos de torsión.

ABSTRACT Objective: The cardiac muscle cannot be anatomically free in the thorax. Therefore, it was thought and analyzed that there could be a myocardial support point (lever fulcrum). Material and Methods: Cardiac dissection in ten young (two years old) bovine hearts (800-1000 g); and in eight human hearts ( one embryo, 4 g; one 10 years old, 250 g; and six adult, mean weight 300 g) were performed. The myocardial band was unrolled in its entirety. The extracted pieces were analyzed by anatomy and histology. A study with magnetic resonance images, tomography and simple radiology was also carried out. Results: In anatomical investigations we have found in all the human and bovine hearts studied a nucleus underlying the right trigone of bone, chondroid or tendon histological structure. The microscopic analysis revealed in bovine hearts a trabecular osteochondral matrix (fulcrum). In the ten year old human heart and in the fetus, a central area of the fulcrum formed by chondroid tissue was found. Histology found a tendon matrix in adult human hearts. This fulcrum is attached to the myocardium and would serve to support both the origin and the end of the myocardium. The images showed evidence of the cardiac fulcrum. Conclusions: The cardiac fulcrum found in the anatomical investigation of bovine and human hearts would clarify the point of support of the myocardial muscle to complete its rotating function.